Abstract Bookphysics.unipune.ac.in/~rmc/2018/RMC2018_Abstract_book.pdfYogesh Jadhav Quaternary Semiconductor Nanocrystals: An Electrochemical Investigation of Band Edge Parameters

Organized by,

Research Students,

Department of Physics,

Savitribai Phule Pune University, Pune, India.

24th Raman Memorial Conference

on

Unravelling Physics of Advanced Materials

23rd - 24th February, 2018

Abstract Book

ABSTRACT BOOK

24th Raman Memorial Conference

23rd - 24th February, 2018

rmc - 2018

Organized by, Reasearch Students,

Department of Physics,Savitribai Phule Pune University,

Pune, India.

Our

Sponsors

Ambai Computers

Anna Canteen

Ashish Stationary

National Centre for Radio Astrophysics of the

Tata Institute of Fundamental Research (NCRA-

TIFR)

The Inter-University Centre for

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MESSAGE BY HOD

It gives me immense pleasure to write this foreword on the occasion of the

Raman Memorial Conference 2018 to be held on 23rd & 24th February, 2018 in

the Department of Physics, S. P. Pune University. As Head of the Department of

Physics, I am proud to point out that Raman Memorial Conference is one of the most

important annual academic events of our Department. As it is being conducted in

our Department continuously since 1994, this year the conference embarks on the

milestone of silver jubilee. In this era, Materials Science has emerged as prime area

of research hence the theme for this conference is rightly chosen to be Unravelling

Physics of Advanced Materials. The fact that the conference is entirely managed by

the students is the USP of this conference. Hence, the conference not only

contributes to the academic enrichment of the students but also prepares them to

shoulder administrative responsibilities. The research students of the

Department work tirelessly to plan the details of the conference and to execute

their plans to make it a successful conference. The postgraduate students of

the department also actively participate in the RMC and are able to get a

glimpse of research world. I am sure that like every year, even this year the

conference will provide a distinctive opportunity to delegates to exchange

ideas with the renowned plenary speakers about the latest developments in

diverse research areas and have fruitful academic interactions with fellow

participants. I wish RMC 2018 a great success.

Prof. S. W. Gosavi

Head, Department of Physics

S. P. Pune University, Pune.

CONFERENCE THEME

Unravelling Physics of Advanced Materials

Advanced materials refer to all new materials and modifications to

existing material to obtain superior performance in one or more

characteristics that outperform conventional materials in their applications

e.g. Graphene, an allotrope of carbon and worlds first 2D material has

captured the attention of scientist, researchers and industry worldwide due

to its novel electronic, optical and mechanical properties.

Many such materials and their process technologies can open a way for

their exploitation in wide spectrum of applications ranging from electronics to

optics, sensors, bio devices and many more. With this perspective, RMC-2018

throws light on the fundamental physics of advanced materials and a wide

spectrum of their applications.

LOCAL ORGANIZING COMMITTEE

Mr. Subhash Pandharkar

Mr. Amol Vedpathak

Ms. Rupali Kulkarni

Ms. Shruthi Nair

Ms. Shalaka Kamble

Ms. Neha Ghodke

Mr. Shridhar Puranik

Mr. Bharat Baraskar

Mr. Vishal Kadam

Mr. Ravindra Waykar

Mr. Bharat Bade

Mr. Pravin Kadane

Mr. Ajinkya Bhorde

Mr. Somnath Bhopale

Ms. Sameena Mulani

Ms. Shraddha Mahakal

Table of Content

ID No. Author and Title of Paper Page No.

Invited Talks

Keynote

Prof. Dinesh Amalnerkar

Bridging the Gap between Vedic Science and Modern Science: Nano-centric

Healthcare Revelations

02

IT-1 Prof. Dilip G. Kanhere

Research: A Serious Endeavour 03

IT-2 Dr. G. V. Pavan Kumar

Nanowire Gap- Plasmons assisted Raman Scattering 04

Thesis Presentations

TP-1

Yogesh Jadhav

Quaternary Semiconductor Nanocrystals: An Electrochemical Investigation

of Band Edge Parameters and Their Solar Cell Applications

06

TP-2

Gayatri Dhamale

Study of Radio Frequency Plasma Synthesis of Ceramic Oxides: Simulation

and Characterization

07

TP-3

Prashant Bankar

Synthesis and Characterization of BiOI-GO, CdS-Bi2S3 and MoO3-RGO

Nanocomposites and their Multifunctional (Photo detection, Photocatalytic,

Humidity Sensing and Field electron Emission) behaviour

09

TP-4

Avinash Rokade

Synthesis and opto-electronic properties of metal oxide core-shell nano-

materials by electrodeposition for Photo-electrochemical water splitting

10

TP-5 Shankar Kekade

Crystallographic and electronic behaviour of Bismuth Vanadate 11

TP-6

Ganesh Bhand

Metal and Semiconductor Nanostructures for Hybrid Organic-Inorganic

Solar Cells

13

TP-7

Onkar Shinde

Study of selected processes in solar cell fabrication for reducing input

energy

15

Oral Presentations

OP-1

S. Premkumar

Effect of Poling Parameter on structural and piezoelectric properties of Sr,

La doped PZT Ceramics

17

OP-2

Prashant Gaikwad

Stability and electronic structure of bulk-like non-stoichiometric ZnO

clusters.

18

OP-3

Imran Shaikh

Highly sensitive thermally grown Ag nanoparticles for the application of

surface enhanced Raman scattering.

19

OP-4 Aniruddha Kibey

Transport Properties of Zigzag SnSe Nanoribbons 20

OP-5

Mohammad Abdul Haque

Low temperature Photoluminescence study of d-d transitions in Mn-doped

ZnSe nanocrystals

21

OP-6

Manasi Mahabal

Sensing Behaviour of B-N-C Monolayer towards Greenhouse Gas molecules :

DFT Study

22

OP-7

Suyog Raut

Synthesis of Iron Oxide Polymorphs by Thermal Plasma and Their

Application in the Development of Mechanical Vibration Damper

23

OP-8

Chandrima Paul

Metallic and antiferromagnetic fixed points from gravity 25

OP-9

Sumayya Anasari

Nanostructured CoFe2O4 micro-granules for Adsorption of Pb(II) from

Aqueous Solution

26

OP-10

Deepashri Saraf

Enhancement of HER and OER Activity

Through Vacancy Defect and Functionalization in Stable PdS2 Monolayer

28

OP-11

Ashwini Datar

Observation and manipulation of magnetic domains in sol gel derived thin

films of zinc substituted Nickel ferrite

29

OP-12 Sandip Wadhai

Copper based Super hydrophobic Surface and granulation for Liquid Marble 30

OP-13

Bhavana Keswani

Investigation of Structural, Ferroelectric, Piezoelectric and Dielectric

Properties of Ba0.92Ca0.08TiO3-BaTi0.96Zr0.04O3 Lead-free Electro ceramics

31

OP-14

Ravi Ingle

Electrical and Optical Properties of Nanocrystalline Cadmium Sulphide and

their Solar Cell applications

32

OP-15

Supriya More

Atmospheric plasma torch for the degradation of highly contaminated water

with organic dye and use of treated water for the growth of chick pea plant

33

OP-16

Laxman Tatikondewar

Electronic Structure of Graded Semiconductor Layered Structures for Solar

Cell Application.

34

OP-17

Dnyaneshwar Bhosale

Ultrahigh Mixed Ionic-Electronic Conductivity below 400C

in Garnets CaxY3-xFe5O12- for LT-SOFC technology

35

OP-18

Ambadas Phatangare

Ultra-high sensitive SERS substrates of 3 nm gold nanoparticles embedded

on SiO2 nanospheres with nanogaps 1 nm for fingerprint detection of

pesticide and dye at ~ 1018 M

36

OP-19

Sameer Salunkhe

Detection of Di_use Synchrotron Emission from Large Scale Structure Using

Radio Astronomical techniques

37

OP-20

Shalaka Kamble

Synthesis of Nanocrystalline Lanthanum Cerium Hexaboride by thermal arc

plasma gas phase condensation route

38

OP-21

Prateek Gupta

Numerical modelling of synchrotron radio emission from large scale

structures of the Universe

40

OP-22 Aparna Shinde

Stimulated emission and polarized emission of CsPbBr3 nanocrystals 41

OP-23

Shridhar Puranik

Feasibility of synthesizing Aluminium Boride High Energy Materials Using

Thermal Plasma Reactor

42

OP-24

Reju Sam John

Energetics and the Evolving Dynamical States of Large

Scale Structure in the Universe

44

OP-25 Archana U. Chavan

Formation and characterizations of NiO -GDC/GDC structure for IT-SOFC 45

OP-26 Balu Thombare

Physical properties of Nd1-xSrxMnO3 (0.3x 0.7) nanoparticles 47

OP-27 Shrikant Kulkarni

Hydrothermal Synthesis and Electrochemical Properties of C:MnFe2O4 48

OP-28

Mahesh Badhane

The linear Response of CaF2:Dy Dosimeter to Radiation Dose Studied by

Thermoluminescence

50

OP-29

Bhagyashri Bhangare

NO2 Sensing andAdsorption-Desorption Behaviour of SnO2/RGO

Nanocomposite

51

OP-30

Krishna Daware

Optical detection of Hg(II) ions in aqueous samples by functionalized gold

NPs

53

Poster Presentations

PP1

Deepali Ghone

Effect of Ho substituting on the magnetoelectric properties of composite of

CoFe2O4 and PSZT.

56

PP2

Pravin Kadhane

Dielectric and Ferroelectric Properties of Ca2+ and Sn4+ Modified

Ba0.97Ca0.03Ti0.97Sn0.03O3 Lead-Free Electroceramics

57

PP3

Sushant Haldkar

Mechano-Milling Effect on Zinc Ferrite Nanoparticles for Psuedocapacitor

Applications

58

PP4

Tulshidas Darvade

Structural and magnetostrictive properties of NiFe2O4ferrimagnetic oxide

synthesized by solution combustion method

59

PP5

Vaishali Thakare/Suwarna Pawar

Synthesis and structural morphological, optical and electrical properties of

chemically deposited PbS films

60

PP6 Sonali Hapse

FNC based split ring resonators for electromagnetic Cloaking in X band 61

PP7

Roshni Rajith

C.dots from Geera: An efficient green approach to an on-off

photoluminescence probe for Fe3+ ion sensing

62

PP8

Abhilasha Sharma

Studies on CH3NH3PbI3 powder prepared by a simple chemical reaction

method

63

PP9 Ashish Kumbhar

Synthesis of rGO/MnO2 composite using hydrothermal method 64

PP10

Aditi Lohkare

Synthesis and characterisations of transition metal dichalcogenides cobalt

and nikel selenides

65

PP11 Aditi Kulkarni

Investigating diffusion of boron into Silicon (100) substrate 67

PP12

Rubeena Sajid

Spin coated Ag nanoparticles SERS substrate for Trace detection of

methylene blue

68

PP13

Sagar Nikam

Effect of milling time on mechanochemically synthesized BiVO4

nanoparticles for visible light Photocatalysis

69

PP14

Smita Yadav

Facile fabrication of TiO2/C3N4 composite photocatalyst with enhanced

photocatalytic activity

70

PP15 Sneha Kandare

Raman spectroscopic study of Nano-Cu2ZnSnS4 under high pressures 71

PP16

Mandakini Shinde

Interaction of antihypertensive drug and protein by fluorescence

spectroscopy

72

PP17

Asif Shaikh/Ankita Kulkarni

Investigating the effect of Microgravity on cellular Growth and Physiology of

Escherichia coli and Saccharomyces cerevisiae

73

PP18

Deeraj Kumar

Electrometric Studies of Ternary Complexes of some Transition Metal

Complexes

74

PP19

Indra Hang Subba

Effect of transverse magnetic field on electromagnetically induced

absorption in 87Rb

75

PP20

Mishael Joseph

A theoretical study of structural, electronic and magnetic properties of iron

oxide clusters

76

PP21 Namrata Jaykhedekar

First-principles Study of Polarization and Piezoelectric Properties of PbZrO3 77

PP22

Nilkantha Tripathi

Ab-initio electronic structure of Corrugated Graphene and adsorption of

9water molecule on Corrugated Graphene.

78

PP23

Shruthi Nair

First principles study of structural and electronic properties of Tl-Bi halide

based double perovskite for PV applications- Cs2TlBiI6

79

PP24 Nishal Rai

Holographic Fermi surfaces 80

PP25 Swarnim shirkhe

Breath figures of volatile surface: Growth dynamics 81

PP26 Vipul Ghemud

Electronic structure study of Mn, Cu and Yb doped SnO2 82

PP27 Rinku Datkhile

Phonon dispersion analysis of Graphene 83

PP28

Arati Mehere

Surfactant free synthesis of Gold nanostars in aqueous medium by seed

mediated growth method

84

PP29 Himani Bhagvat

Synthesis and Characterization of PANI / ZnO Nanocomposites 86

PP30 Nilima Kandhare

Synthesis and Characterization of RGO/NiO composite 87

PP31

Kalyanee Patil

Synthesis and Characterization of Zinc Ferrite using Thermal Decomposition

Method

88

PP32 Vaishali Pisal

Study of Anti-microbial Activity of CeO2 Nanoparticle 89

PP33

Rutuja shinde

Synthesis and Characterization of CoSe2 Nanoparticles by Hydrothermal

Method

90

PP34

Mandar Kulkarni

Effect of anneling temperature on morphology and electrical properties of

Indium tin oxide.

91

PP35 Sheetal Malvankar

Structural and optical properties of Co-doped SnO2 nanoparticles 93

PP36 Shraddha Mahakal

Role of Amino acid in synthesis of ZnO nanostructure 94

PP37

Swapnil Doke

Low power operated highly luminescent ferroelectric liquid crystal doped

with CdSe / ZnSe core/shell quantum dots.

95

PP38

Bheem Singh Jatav

Numerical simulation of kinetic Alfven waves for intermediate plasma to

study localized structure of solar wind.

96

PP39

Gajanan Harale

Role Of Fermi I and Fermi II mechanisms in modulating electron energy

spectrum responsible for radio emissions in Galaxy clusters

97

PP40

Mukul Mhaskey

Radio continuum emission and HI gas accretion in the NGC 5903/5898

compact group of early-type galaxies

98

PP41

Sachin Budakoti

Potential of WRF model to simulate the cloudburst event over Pithoragarh

distict of Uttarakhand- a case study

99

PP42 Shalmalee Kapse

How to predict unknown rocks? 100

PP43

Sudip Kundu

Computation of flood drought year by using IMD monthly rainfall over

Gangetic Plain

101

PP44 Venkat Punjabi

Study of energetic and dynamics of SDSS Galaxy groups 102

PP45 Dr. Sanjeev kumar singh

Validation of SCATSAT-1 Scatterometer winds with in-situ observations 103

PP46 Ashvini Varpe

Characteristics of Sn doped ZnO Thin Films as CO and CO2 104

PP47

Kranti Khairnar

Use of TiO2 nanotube arrays with sandwich structure on Nickel for

betavoltaic nuclear battery

105

PP48

Suraj Gaikwad

Electrochemical deposition of ZnO/Fe2O3 core-shell photoanode for

enhanced photocatalytic water splitting

106

PP49

Susmita Kaware

Fabrication of Ag-sensitized ZnO photo electrode by electrodeposition for

photoelectrochemical water splitting

107

PP50 Varsha Bachhav

Investigation of 2D Transition metal dichalcogenides. 108

PP51

Vindhyavasini Pandey

A study on the dose prediction accuracy of pencil

beam convolution algorithm for effective radiotherapy

109

PP52

Yogeshri Bagekari

Study of post annealing effect on structural , morphological, functional and

Dosimetric properties of SrF2 Nanophosphor

110

PP53

Bharat Bade

Synthesis & Characterization of Tio2 Nanostructures by Hydrothermal

Technique for Solar Cell Application

111

PP54 Bushan Kamble/Dnyanesh Kedar

Preparation of perovskite solar cell by using Slot- die technique 112

PP55 Haribau Bhorate

DC Sputtered molybdenum (Mo) back contact for CZTS thin film solar cell 113

PP56 Niyamat Beedri

Nb2O5 based Photoanode for dye sensitized solar cell: Blended dye 114

PP57

Pankaj Jagdale

Synthesis and Characterization of Zinc Oxide Nanorods Using Simple

Chemical Method for Dye Sensitized Solar Cells Application

115

PP58

Sonali Wakchaure

Performance of Dye Sensitized Solar Cell using TiO2 Film under

Incandescent Light

116

PP59 Mukud Kakare

ON-Grid perfomance analysis of 3 KW solar roof of PV system 117

PP60

Chaitali Jagtap

Influence of Dye Loading Time on Porous TiO2 Based Dye Sensitized Solar

Cell

118

PP61

Vishal kadam

Studies on Influence of SILAR CdS sensitization on the Photovoltaic

Performance of TiO2 Based Solar Cell

119

PP62

Kadambari Kasar

Preparation of Cu ZnS4 Thin films at low temperature for optoelectronic

operation.

120

PP63 Mangesh Desai

Electrochemical studies of pesudocapacitor Mn3O4 thin films 121

PP64

Mangesh Deore

Temperature dependant characterization of ZnO thin films using physical

vapor deposition technique

122

PP65 Pavan Jadhav

Synthesis, Characterization of SnO thin films prepared by Spray Pyrolysis 123

PP66 Vivek Kale

Study of cyclic voltammetry for CZTS thin film solar cell 124

PP67 Shital Kanaskar

Wireless data acquisition system: XBee 125

PP68 Manisha Gunjal

Study of Glare caused by Indoor Illumination Systems 126

PP69

Mukta Verma

Development of a 2D electrical impedance tomography system for studying

conductivity distribution of particle phantom with circular inhomogenities

127

PP70 Manjiri Mahadadalkar

Does Pt Loading Improve the Photocatalytic response of CdIn2S4? 129

PP71

Minnath Kolpe

Miniaturization of Electronic Circuits Using In House Developed Resistor

Paste

130

PP72

Sarika Jadhav

Synthesis and Characterization of Graphene and Graphene based Metal

oxide nanocomposite for Energy Storage Application

131

PP73

Bikram Prasad

Sensitization effectof Zirconia Films with Lead Sulphide for their

Applications in Solar Cells

132

PP74

Shreelekha N. Khatavkar

Supercapacitive performance of Copper Oxide Thin Films deposited by

Liquid Phase Deposition

133

PP75

S.A. Mahalunkar

Synthesis and Characterization of Gold Nanoparticles anchored to Folic Acid

using Non-Covalent Interaction via Polyvinyl pyrrolidone Backbones for

Cancer Therapy

134

PP76

Akshay Vyas

SILAR grown nickel nanoparticles for ethanol electrooxidation: Effect of

nickel concentration

136

24th Raman Memorial Conference-2018

1

Invited

Talks


2

Bridging the Gap between Vedic Science and Modern Science:

Nano-centric Healthcare Revelations

Prof. Dinesh Amalnerkar*

Nanoparticles Technology Laboratory, School of Mechanical Engineering

Sungkyunkwan University (SKKU)

Suwon, Gyeonggi- 440-746, South Korea

&

Institute of Nano Science and Technology

Hanyang University,Seoul- 04763

South Korea

* E-mail address: [email protected]

While exploring healthcare applications of nanomaterials, it is intuitively sensed that

therapeutic properties of metal based ayurvedic compositions might be associated with nano-

scale features. To get head start, we collected Au,Ag and Zn based metallic compositions

which were used successfully in cancer treatment by renowned ayurvedic specialist and

planned their physico-chemical investigations. Such samples were believed to be prepared

by following traditional ayurvedic protocol in toto. Ultramodern analytical tools such as X-

ray Diffractometry (XRD), Field-Emission Scanning Electron Microscopy (FESEM), X-ray

Photoelectron Spectroscopy (XPS),Transmission Electron Microscopy (TEM),High-

Resolution TEM (HRTEM), Scanning Transmission Electron Microscopy(STEM) with High

Angle Annular Dark-Field (HAADF) and Elemental Mapping were employed to judge

structure, morphology and elemental/chemical composition and distribution. To put the

subject matter in proper perspectives of nanotechnology and healthcare, I have structured my

presentation in two parts entitled below:

Part-I (Modern Science)

Anti-microbial behavior and innovative biofilm inhibition by molybdenum sulfide

nanostructures generated via microwave assisted solvothermal route.

Part II (Vedic Science)

Poly-dispersed nanostructures in ayurvedic metal based compositions practiced in Cancer

Treatment.

The perplexing findings will be presented in this discourse which can surly play illustrative

role in bridging the gap between vedic science and modern science.

Keynote

mailto:[email protected]


3

Nanowire Gap-Plasmons Assisted Raman Scattering

Dr. G.V. Pavan Kumar

Indian Institute of Science Education and Research (IISER)

Pune - 411008, INDIA

Abstract:

In this talk, I will give an overview of gap plasmons, and how they can be utilized to obtain

Raman optical antennas. I will present our recent work on momentum-resolved surface-

enhanced Raman scattering and the prospects of using it to understand molecular vibrations

in gap-plasmon cavity.

IT-01


4

Research: A Serious Endeavour Prof. D G Kanhere

Science Park and CMS, SPPU Pune

Abstract

Although it is possible to enumerate and formally state various steps for carrying out

research, research carrier is a life style. Courses on research methodology do set up some

guide lines and may be able to create frame work for conducting research, but it must be

remembered that undertaking such a course is not a necessary or sufficient condition. It will

help, at best!

I will discuss many facets of research and will conduct an interactive session with the

students. The talk is based on my personal experience and will necessarily reflect my point of

view which may not be universal.

IT-02


5

Thesis

Presentation


6

Quaternary Semiconductor Nanocrystals: An Electrochemical

Investigation of Band Edge Parameters and Their Solar Cell Applications

Yogesh A. Jadhav1, Pragati R. Thakur1 and Santosh K. Haram1,2*

1Department of Chemistry, Savitribai Phule Pune University (Formerly University of Pune),

Ganeshkhind, Pune 411007, India 2National Center for Nanoscience and Nanotechnology, Mumbai University, Mumbai 400098, India

Presenting author: [email protected]

Abstract: The charge transfer processes occurred in solar photovoltaic devices takes place via band edges. Thus,

tuning the band edge position and making them favorable as per requirement is utmost important.

Tuning of these position can be done by change in size, shape, ligands and composition. Herein, we

have synthesized and studied various earth abundant, low cost, eco-friendly quaternary semiconductor

alloy nanocrystals. The different compositions were prepared by varying anions and cations (complete

and partial replacement of element from the quaternary semiconductor). For solar cell and other

optoelectronic application, the band gap and band edge positions are very crucial parameters, which

were estimated using simple and economic electrochemistry approach. In this thesis parent material

for quaternary semiconductor is Cu2ZnSnS4 (CZTS), for engineering band gap and band edge

positions its different composites were prepared viz. (1) Cu2ZnSn(SxSe1-x)4, (2) Cu2XSnS4 (X= Mn,

Fe, Co, Ni, Cd etc.), (3) Cu2ZnxFe1-xSnS4 and (4) Cu2ZnxCd1-xSnS4. By using cyclic voltammetry band

structure parameters of these quaternary semiconductor nanocrystals composites were estimated. In

addition to the synthesis, characterization of nanocrystals and estimation of band structure parameters,

the photovoltaic device using Cu2NiSnS4 nanocrystals were fabricated and tested for efficiency.

Figure 1: Summarized results for the thesis work. CV, band gap and band edge positions for alloy

NCs (a) Cu2ZnSn(SxSe1-x)4, (b) Cu2XSnS4 (X= Mn, Fe, Co, Ni, Cd etc.), (c) Cu2ZnxFe1-xSnS4 and (d)

Cu2ZnxCd1-xSnS4 and (e) Solar cell device structure and I-V.

TP-01



7

Study of Radio Frequency Plasma Synthesis of Ceramic Oxides:

Simulation and Characterization

G. D. Dhamale

Research Scholar

Savitribai Phule Pune University, Pune, India-411 007


Abstract: Nanoparticles of metals, semiconductors and metal oxides are of great interest for a wide variety of

applications due to their unique or improved properties determined primarily by their size,

composition and structure. The nanoparticles of ceramic oxides, chosen for this study have

applications in wide areas including optoelectronic devices, catalyst, thermal barrier coating, doping

and lasing host material, etc. [1-16]. The different routes adopted in the synthesis of nanoparticles

mainly consist of liquid and gas phase processes. A process of gas phase synthesis offers distinct

advantages over liquid phase synthesis in terms of production rate, yield of the material, less exposure

to hazardous chemicals etc [1]. Thermal plasma synthesis falls under the category of gas phase

synthesis wherein the Radio Frequency Inductively Coupled Thermal Plasma (RF-ICTP) system

offers a unique advantage due to its high temperature and energy density. It also offers high

production rate, least electrode contamination which differentiates it from the DC Thermal Plasma

synthesis process [17-19]. In both these processes, the production of nanoparticles is usually obtained

by evaporating the micron sized powders and subsequently condensing the supersaturated vapor [20].

Production of high quality ceramic powders is one of the most important objectives in the ceramic

industries. Due to the refractory nature, the production of fine ceramic powders with superior

properties is a challenging task. Thermal plasma with their inherent processing capabilities not only

accepts this challenge but also offers a high yield of good quality ceramic nanoparticles in a single

step without requiring any post-treatment.

Although a large body of work is available for nano-synthesis in thermal plasma system, major

problem lies in the reproduction and predictability when a different device is used or different

operating regimes are employed for similar synthesis. This is primarily due to the lack of

understanding of the physics behind the formation of nano-structures and influence of the

environmental parameters. While a large number of synthesis and routine characterization work is

available, efforts in theoretical understanding of the process through simulation or fundamental

studies are very limited. Along with the experimental study of the synthesis, present study proposes to

address the problem in the second area as well. Two major quantities that determine the synthesis

process involve the distribution of flow vector and thermal fields inside the synthesis zone. The robust

way to understand these two parameters includes the simulation using CFD (Computational Fluid

Dynamics) tool. The formation of nanoparticles in thermal plasma occurs by homogeneous nucleation

whereas the growth process is highly dependent on the cooling rate offered by the steep temperature

gradient in the system. The CFD simulation feeds this information and one can study the process of

nanoparticle formation using this by aerosol modeling.

In the present work, we have synthesized nanoparticles of three important ceramics viz, Aluminum

oxide (Al2O3), Yttrium Oxide (Y2O3) and Neodymium Oxide (Nd2O3) in RF-ICTP reactor.

Characteristics of the synthesized nanoparticles have been studied using various analytical tools.

Plasma diagnostics were carried out for determination of the plasma temperature during synthesis

using optical emission spectroscopy, a non-intrusive method of temperature determination. Fluid

dynamic simulation and aerosol modeling were used for theoretical understanding of the plasma fluid

dynamics and the synthesis process.

TP-02


8

References:

[1] Dosi Dosev, Bing Guo, and Ian M Kennedy Journal of Aerosol Sci.,37:402-412

[2] Rabiah Nizah, M.F., Taufiq-Yap, Y.H. and Hussein, M.Z., 2013 Advanced Materials Research

620:335-339

[3] Zou, M., Wang, X., Jiang, X. and Lu, L., 2014Journal of Solid State Chemistry, 213:235-241.

[4] Jiang, K., Liu, S. and Wang, X., 2017 Ceramics International,43:12633-12640

[5] Lima, R.S. and Marple, B.R., 2017 Journal of Materials Engineering and Performance,

26(3):1272-1282.

[6] Kablov, E.N., Stolyarova, V.L., Lopatin, S.I., Vorozhtcov, V.A., Karachevtsev, F.N. and

Folomeikin, Y.I., 2017 Rapid Communications in Mass Spectrometry, 31(6):538-546.

[7] Wang, Y., Gauvin, R., Kong, M., Lin, C., Liu, Z. and Zeng, Y., 2017 Surface and Coatings

Technology, 316:239-245.

[8] Abdelghany, A.M., Zeyada, H.M., ElBatal, H.A. and Fetouh, R., 2016 Silicon, 8(2):325-330.

[9] Diao, C.C., Liu, J., Yang, C.F., Kuo, C.G., Chen, C.Y. and Ho, Y.I., 2016 Advanced Materials for

Science and Engineering (ICAMSE)(pp. 263-266). IEEE conference proceeding

[10] Huang, Z., Wang, S., Li, H. and Tan, Z., 2013 Journal of thermal analysis and calorimetry,

113(2):667-671.

[11] Onishi, Y., Nakamura, T. and Adachi, S., 2016Journal of Luminescence, 176:266-271.

[12] Zorenko, Y., Zorenko, T., Gorbenko, V., Savchyn, V., Voznyak, T., Fabisiak, K., Zhusupkalieva,

G. and Fedorov, A., 2016 Optical Materials, 59:141-144.

[13] Gui, Y., Yang, Q., Shao, Y. and Yuan, Y., 2017Journal of Luminescence, 184:232-234.

[14] Pandit, P., 2017 Materials Today: Proceedings, 4(2)3911-3917.

[15] Ikesue, A., Kinoshita, T., Kamata, K. and Yoshida, K., 1995 Journal of the American Ceramic

Society, 78(4), pp.1033-1040.

[16] Lu, J., Takaichi, K., Uematsu, T., Shirakawa, A., Musha, M., Ueda, K., Yagi, H., Yanagitani, T.

and Kaminskii, A.A., 2002 Applied physics letters, 81(23):4324-4326.

[17] Masaya Shigeta and Antony Murphy 2011 J. Phys. D: Appl. Phys., 44:174025

[18] Maher I. Boulos 2016 Plasma Chem. Plasma Process., 36:3-28

[19] Javad Mostaghimi and Maher I. Boulos 2015 Plasma Chem. Plasma Process., 35: 421-436

[20] Mark T. Swihart 2003 Current Opinion in Colloid & Interface Science 8.1: 127-133


9

Metal and Semiconductor Nanostructures for Hybrid Organic-Inorganic

Solar Cells

Ganesh R. Bhand, N. B. Chaure

Department of Physics, Savitribai Phule Pune University, Pune 411007, INDIA


Abstract

Spherical and rod shaped gold and silver nanostructures (NSs) have been prepared by seed mediated

growth method. In this study, we have investigated the effect of the parameters involved in the

synthesis of nanoparticles and nanorods, such as, concentration of ascorbic acid, CTAB and seed

solution on both transverse and longitudinal plasmon band and its tunability. Different sizes of

semiconductor NSs, such as, CdSe, CdTe and core/shell CdTe/CdSe were prepared by colloidal as

well as solvothermal method. The NSs were characterized using XRD, Raman spectroscopy, TEM,

EDS, UV-visible absorption spectroscopy and PL spectroscopy to study the structural, morphological,

compositional and optical properties. The spherical and rod shape of Au and Ag NSs are confirmed by

TEM images. The reaction times as well as temperature of resulting semiconductor NSs are key

factors for controlling the size and shape was found. The absorption wavelength was found to be red

shifted systematically upon increasing the reaction temperature as well as increasing the reaction time.

The spherical, rod and tripod shape with narrow size distribution of obtained semiconductor NSs was

confirmed by TEM images. The emission spectra of CdTe/CdSe core/shell QDs attributed at higher

wavelength as compared to pristine CdTe demonstrates the indirect excitation in CdTe core.

Different methods have been applied for tuning the optical and electrical properties of the hole

transport layers i.e. PEDOT:PSS films: 1st annealing effect of films; 2nd addition of polar solvent

(sorbitol) into PEDOT:PSS and; 3rd mixing of different concentration of Au and Ag nanostructure, the

obtained results are discussed. Polyaniline (PANI) thin films have been prepared by simple chemical

bath deposition method by using different concentration of doping acid. In this study nanocomposite

films are obtained by dipping the PANI layers into the solution of CdSe(TPs) for various duration.

The nanocomposite thin films of CuPc/CdSe produced by different concentration of QDs varied in

CuPc. The optical, structural and morphological properties of nanocomposite films have been

investigated.

The various type of devices are fabricated such as, 1) ITO/PEDOT:PSS/P3HT:CdSe/Al, 2) ITO/

PEDOT:PSS/ P3HT:CdTe/CdSe core/shell /Al, 3) ITO/ PEDOT:PSS:AuNPs/ P3HT:

CdSe:AuNPs/Al, 4) ITO/ PEDOT:PSS/P3HT:CdTe/ Al, 5)ITO/ PEDOT:PSS/ P3HT:CdTe/CdSe

core/shell:AuNPs /Al. The complete photovoltaic device structure was studied and the results are

discussed. I-V characteristics are measured under dark and illuminated conditions. For the first

device, by varying the concentration of CdSe in active layer, the efficiencies were obtained in the

range of 0.41 % to 0.85 %. The FF and Voc measured were 43% and 380 mV, respectively. Upon

dispersion of AuNPs in the buffer as well as active layer, the efficiency enhanced up to 1.32 %. The

various concentrations of CdTe/CdSe core/shell QDs were embedded in the active layer and studied

thoroughly. The Voc and FF are observed in the range of 422-429 mV and 25-30%, respectively. The

AuNPs dispersed in the active layer in presence of core/cell QDs, have an efficiency in the range of

0.57% to 0.90 % and FF and Voc in the range of 26-29% and 429-436 mV, respectively.

TP-03


10

Acknowledgments

The financial support received from Department of science and technology (DST), New Delhi under

the major project grant DST/TM/SERI/FR/124/G is gratefully acknowledged. GRB is thankful to University

Grant Commotions (UGC) for BSR fellowship.

References

1. K. D. Smith, H. K. Gummel, J. D. Bode, D, B. Cuttriss, W. Rosenzweig, Bell Labs technical journal,

42 (1963) 1765.

2. A. G. MacDiarmid, Angew. Chem. Int. Ed. 40 (2001) 2581.

3. L. Dou, J. You, J. Yang, C. C. Chen, Y. He, S. Murase, T. Moriarty, K. Emery, G. Li, Y. Yang, Nat.

Photon. 6(2012)180185.

4. G. R. Bhand, M. G. Lakhe, A. B. Rohom, P. U. Londhe, S. K. Kulkarni and N. B. Chaure, Journal of

nanoscience and nanotechnology, 18 (2018) 2695-2701.

5. Z. He, C. Zhong, S. Su, M. Xu, H. Wu, Y. Cao, Nat. Photon. 6(2012)593597.

6. Z. He, C. Zhong, X. Huang, W.-Y. Wong, H. Wu, L. Chen, S. Su, Y. Cao, Adv. Mater. 23 (2011)

46364643.

7. J. Zhou, X. Wan, Y. Liu, Y. Zuo, Z. Li, G. He, G. Long, W. Ni, C. Li, X. Su, Y. Chen, J. Am. Chem.

Soc. 134 (2012) 1634516351.

8. R. Saravanan, E. Sacari, F. Gracia, M.M. Khan, E. Mosquera, V. Gupta, J. Mol. Liq. 221(2016) 1029

1033.

9. G. R. Bhand, N. B. Chaure, Mater. Sci. Semi. Proc. 68 (2017) 279287.

10. C.Y. Kuo, M. S. Su, Y. C. Hsu, H. N. Lin, K. H. Wei, Adv. Funct. Mater. 20 (2010) 3555-3540.

11. D. Kozanoglu, D. Apaydin, A. Cirpan, E. N. Esenturk, Org. Electron. 14 (2013) 17201727.

12. G. R. Bhand, P. U. Londhe, A. B. Rohom and N. B. Chaure, Advance Science Letter, 20 (2014) 1112-

1115.

13. A. Apte, P. Joshi, P. Bhaskar, D. Joag, S. Kulkarni, App. Sur. Sci. 355 (2015) 978983

14. Z. Cao, Z. Chen, L. Escoubas, Opt. Mater. Exp. 4(2014)2525

15. V. Kumar, V. Patil, A. Apte, N. Harale, P. Patil and S. Kulkarni, Langmuir, 31 (2015) 13247.

16. G. R. Bhand, M. G. Lakhe1, A. B. Rohom, P. U. Londhe, S. K. Kulkarni, N. B. Chaure, J. Mater. Sci: Mater Electron DOI 10.1007/s10854-017-7079-z


11

Study of selected processes in solar cell fabrication for reducing input

energy

Onkar Shinde

School of Energy Studies, Savitribai Phule Pune University, Pune-411007 Department of Electronic Science, Pune-411007


Abstract:

High quality cost effective fabrication processes without compromising with device efficiencies are

necessary to reduce the economical budget of the solar cell fabrication. Low cost processes provide

different ways to reassess conventional material choices and processing steps. Further, these processes

helps to provide the directions to improve the device performance and reduced manufacturing costs

[1,2]. In this dissertation, we have investigated several aspects which could potentially help to reduce

the cost of solar energy.

First, we have developed a low temperature passivation and antireflection process for the AL-BSF

multi-crystalline silicon solar cells. We have used the Oleylamine and epoxy for the passivation and

antireflection coating for the AL-BSF devices [1,4,3]. Second, in thin film CIGSe Solar cell

fabrication we have fabricate the solar cells and absorber preparation is done with the alternative

potential precursor Diethyl Selenied (C2H5)2-Se instead of Hydrogen Selenied (H2Se) [5]. At last, we

have studied the reliability and degradation of multi-crystalline solar modules with different

encapsulants installed in the hot and humid environment [6,7]. Together with the encapsulation

degradation we have also studied the other degradation modes such as crack induced hots-spot and

corrosion.

It is expected that all these research and developments will ultimately help PV community to reduce

the energy intensiveness of commercial photovoltaic fabrication processes.

References:

1. O. S. Shinde, A. M. Funde, S. V. Kahane, M. Agarwal, S. R. Jadkar, S. R. Mahamuni, R. O. Dusane, and S. V. Ghaisas, "Construing the interaction between solar cell surface

and fatty amine for the room temperature passivation," Solar Energy, vol. 135, pp. 359-

365, 2016.

2. O. S. Shinde, A. M. Funde, M. Agarwal, S. R. Jadkar, S. R. Mahamuni, R. O. Dusane, N. G. Dhere, and S. V. Ghaisas, "Emitter passivation of silicon solar cell via organic

coating at room temperature," Journal of Materials Science: Materials in Electronics,

vol. 27, pp. 12459-12463, 2016/12/01 2016.

3. Reliability and efficacy of organic passivation for polycrystalline silicon solar cells at room temperature, SPIE- 2016, pp. 99380G-99380G-5.

4. Low temperature surface passivation of silicon solar cells, IEEE, PVSC-2016. 5. CIGSe absorber preparation: an alternative to H2Se, IEEE, PVSC-2017. 6. Low temperature antireflection coating for silicon solar cells, IEEE, PVSC-2017. 7. Encapsulation performance after 3 years in the field: A comparison of hot/humid and

hot/dry climates. PVMRW- 2017, NREL Conference.

8. Degradation Analysis of PV Modules After Long-Term Exposure in Florida, IEEE, PVSC-2018

TP-04

https://www.researchgate.net/publication/311255336_Low_temperature_surface_passivation_of_silicon_solar_cells?_iepl%5BviewId%5D=aQVN0VmMr6uen0Q8wo0U0mnx&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BtargetEntityId%5D=PB%3A311255336&_iepl%5BinteractionType%5D=publicationTitlehttps://www.researchgate.net/publication/320434068_CIGSe_absorber_preparation_an_alternative_to_H_2_Se?_iepl%5BviewId%5D=aQVN0VmMr6uen0Q8wo0U0mnx&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BtargetEntityId%5D=PB%3A320434068&_iepl%5BinteractionType%5D=publicationTitlehttps://www.researchgate.net/publication/320434064_Low_temperature_antireflection_coating_for_silicon_solar_cells?_iepl%5BviewId%5D=aQVN0VmMr6uen0Q8wo0U0mnx&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BtargetEntityId%5D=PB%3A320434064&_iepl%5BinteractionType%5D=publicationTitle


12

Synthesis and Characterization of BiOI-GO, CdS-Bi2S3 and MoO3-RGO

Nanocomposites and their Multifunctional (Photodetection, Photocatalytic, Humidity

Sensing and Field Electron Emission) behavior

Prashant K. Bankar

Research Scholar

Savitribai Phule Pune University, Pune, India-411 007 Presenting author: [email protected]

Abstract: The research activity in the area of nano-materials thus started really getting momentum and soon,

there was an explosion of research interests in this field. The inventions of newer and newer types of

nano-materials, their properties and concepts of exploring their applications has now-a-days become

an important factor of materials technologies. These nano-sized configurations include nano-

materials in the variety of shapes such as nano-rod, nano-sheets, nano-flower and so on. Recently, 1D,

2D, and 3D nanostructures have also been created and are being investigated for their use in synthesis

of well aligned patterns and device structures of nano-materials and their possible application. The

nano-sized materials have distinctive size and shapes, surface chemistry and the topology. It has been

realized that by controlling the size and shape of nanoparticles, their optical, electrical, magnetic,

dielectric etc. properties can be tuned with higher precision.

In recent years field emission of electrons from nanomaterials has drawn considerable attention

owing to their potential use in a variety of the applications such as flat panel display X-ray sources,

electron microscopes, microwave devices etc. In field emission, electrons tunnel through a potential-

energy barrier at the solid-vacuum interface and then escape to vacuum due to the presence of an

external electrostatic field. From application point of view, for fabrication of cold cathodes based on

nanostructures, two parameters viz, the aspect ratio and work function are very important. It is

desirable that the nanostructures should have high aspect ratio and low work function.

Semiconductors materials have also attracted much interest for their favorable properties because of

their high physical as well as better chemical stability. Among these materials, Bi2S3, CdS, MoO3 and

BiOI have been extensively studied because of its long-term thermodynamic stability, low cost and it's

optical as well as electrical properties. Nowadays, significant attention has been given to developing

semiconductor-based heterostructures and nanocomposite systems for high-quality multifunctional

activity. Graphene (GO) and reduced graphene oxides (RGO) due to its high electrical and thermal

conductivity, along with high charge carrier mobility is recognized as a potential candidate for

nanocomposite formation aimed at enhancement electrical conductivity and/or pathways for charge

carriers transport.

The work reported in this thesis aims to the controlled synthesis of BiOI-GO, CdS-Bi2S3 and MoO3-

RGO Nanocomposites and their Multifunctional (Photodetection, Photocatalytic, Humidity Sensing

and Field Electron Emission) behavior in detail. Various physicochemical characterization techniques

such as, X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), High-

Resolution Transmission Electron Microscope (HRTEM), Selected Area Electron Diffraction

(SAED), Photoluminescence (PL), Raman, UV-Visible spectroscopy (UV) and Field Emission

Microscopy (FEM) have been employed for characterization of these nanostructures.

TP-05



13

Synthesis and opto-electronic properties of metal oxide core-shell nano-

materials by electrodeposition for Photoelectrochemical water splitting A. Rokadea, S. Rondiyaa, V. Sharmaa, M. Prasada, S. Jadkara

bDepartment of Physics, Savitribai Phule Pune University, Pune 411 007, (India)


Abstract:

Photoelectrochemical (PEC) decomposition of water demonstrated by Fujishima and Honda in 1972

[1] is a clean and green way to produce hydrogen and is widely recognized as a viable alternative to

fossil fuels.

Recently, vertically aligned one-dimensional ZnO arrays on a conducting glass substrate are emerging

as promising alternatives to nanocrystalline TiO2 films. ZnO possesses much higher electron mobility

than TiO2. The electron mobility of ZnO is 115-155 cm2 V-1s-1 [2, 3, 4] and that of TiO2 is around 10-

5 cm2 V-1 s-1 [5]. Zinc oxide (ZnO) is an n-type semiconductor with direct band gap energy of 3.37 eV

at room temperature and the nanomaterials of ZnO exhibit several distinct advantages such as simple

tailoring of the structures, because of their suitable band gaps, higher carrier mobility, facile and low-

cost for large-scale manufacturing, stability against photo corrosion, high photocatalytic activity and

so on. Among various sensitizing materials, Fe2O3 & CdS has been widely used because of its narrow

direct band gap semiconductors and have suitable band alignment with ZnO. The electrons are

injected from conduction band of narrow band gap material to the conduction band of ZnO leading to

easy movement & collection of charge carriers.

CdS nanosheets(NSs) are synthesized on ZnO nanorods (NRs) to form ZnO/CdS heterostructure &

then it was chracterized using various techniques. From analyzing the results, we observed that the

photocurrent conversion efficiency in water splitting is higher for ZnO-NRs/CdS-NSs hetero-

structures than ZnO-NRs photoanode due to the greatly prolonged lifetime of photogenerated charge

carriers and increased charge carrier density from 2 x1017 cm-3 for Z-NRs to 5 x1018 cm-3 for ZnO/CdS

hetero-structure photoanode. Electrochemical Impedance specta reveals the effective reduction in the

charge transfer resistance in the FTO/CdS electrode after introduction of ZnO NR between FTO and

CdS. The highest % of ABPE 2.30 % was obtained for ZnO-NRs/CdS-NSs sample with

photocurrent density 1.87 mA/cm2 under AM 1.5 G illumination at 100 mW/cm2. These results

demonstrate the synergistic effect of coupled CdS-NSs with ZnO-NRs is beneficial in increasing the

light absorption and to enhance the photocurrent conversion efficiency in water splitting. Thus, ZnO-

NRs/CdS-NSs hetero-structure can be a facile and prospective candidate for efficient PEC water

splitting. Further, Fe2O3 thin films are electrodeposited as a shell layer on ZnO nanorods for various

deposition cycles. The fabricated ZnO/Fe2O3 core-shell photoelectrodes are systematically

investigated for use in photocatalytic water splitting. We found enhanced photosplitting due to the

sensitization of ZnO-NRs with Fe2O3 narrow band gap materials. The obtained results via nano

tailoring will help in overcoming challenges of recombination of charge carriers for Fe2O3 material

towards efficient photo-splitting of water for hydrogen production.

References:

1. A. Fujishima and K. Honda; Nature, 238 (1972) 37.

2. E. Kaidashev, M. Lorenz, K. Han and M. Grundmann; Appl. Phys. Lett., 82 (2003) 3901.

3. B. Theys, V. Sallet and F. Jomard; J. Appl. Phys., 91 (2002) 3922.

4. Z. Ye, Y. Zhang and W. Xu; J. Inorg. Mater., 18 (2003) 11.

5. T. Dittrich, E. Lebedev and J. Weidmann; phys. stat. sol., (a) 165 (1998) R5.

TP-06



14

Crystallographic and electronic behavior of Bismuth Vanadates

Shankar S. Kekade and S. I. Patil

Advanced Material Processing Lab, Department of Physics Savitribai Phule Pune University, Pune 411007,

India Presenting author: [email protected]

Abstract The size confinement accompanied tailoring of electronic structure can in principle, be explored for

enhancement of photocatalytic properties. In the present work, vanadium doped bismuth oxide

nanoparticles, bulks samples as well as the thin films are synthesized using thermal plasma method,

solid state reaction route and pulse laser deposition technique to explore for photocatalytic

applications. The electronic and crystallographic structures of the Bi11VO19 are studied experimentally

and theoretically. Systematic investigations of electronic structure of fluorite type cubic phase of

Bi11VO19 nanoparticle is reported for the first time. Enhancement is observed in the photocatalytic

activity as compared to other delta phases of bismuth vanadate. The study of phase transition in

BiVO4 from tetragonal to monoclinic carried out using structural and electronic measurements.

Bi11VO19 nanoparticles, BiVO4 thin films and monoclinic BiVO4 have shown an efficient visible light

absorption and exhibit excellent photo-degradation properties of methylene blue (MB) solution under

visible light irradiation.

INTRODUCTION:

The photocatalytic splitting of water into hydrogen and oxygen and the photocatalytic degradation of

organic pollutants are promising reactions for solving energy and environmental issues that confront

mankind today. Great progress has been made in the research and application of these reactions since

photoelectrochemical water splitting (HondaFujishima effect) was reported in 1972 [1]. In the

present time, developing visible-light-responsive photocatalysts is the most important direction for

this field, because the utilization of visible light, which accounts for more than half of the solar

spectrum in significant. Among large number of catalysis used for H2 and O2 evolution under visible

light, semiconductor with appropriate valence band edge has attracted more attention. Bismuth

vanadate is one of these visible-light responsive photocatalysts. The details investigation of electronic

properties was necessary to enhance the photocatalytic activity. In the present work, the electronic

structure of samples is studied experimentally and theoretically. The monoclinic scheelite BiVO4

exhibits high activity, not only for photocatalytic O2 evolution from aqueous AgNO3 solutions, [2] but

also for the photocatalytic degradation of endocrine compounds, such as Methylene Blue (MB), under

visible-light irradiation.

MATERIALS AND METHODS:

Bi11VO19 was synthesized using thermal Plasma method, BiVO4 using solid state method and BiVO4

thin films using Pulse Laser deposition technique. The samples were characterized experimentally by

using XRD, Raman, UV-Visible spectroscopy, TEM, XPS, VBS, XAS and the theoretically using

Density function theory (DFT) based spin-polarized electronic structure calculations which performed

at 0K using accurate plane augmented wave method.

RESULT:

The experimental (structural, optical, and electronic properties) as well as the theoretical (DFT)

results of the studied bismuth vanadate samples are explained. The bismuth vanadate (bulk as well as

Nanoparticles) show the excellent photocatalytic activity for photodecomposition of MB dye under

TP-07



15

the visible light irradiation. The kinetic constant of the MB degradation reaction for all samples are

studied.

Figure: Local ground state geometry and Density of state of Bi11VO19 and Bi44V4O76, Degradation

rate of Bi11VO19 and BiVO4 with different sintering temperature.

CONCLUSION:

This work provides a high yield economic way to prepare highly active visible light driven

photocatalyst for the treatment of organic pollutants of wastewater.

ACKNOWLEDGMENTS:

SSK is thankful to UGC BSR, Delhi for the financial assistance to carry out this research work.

REFERENCES:

1. A. Fujishima, K. Honda, Nature 37 (1972), 238. 2. A. Kudo, K. Omori, H. Kato, J. Am. Chem. Soc. 1999, 121, 11 459.


16

Oral

Presentation


17

Effect of Poling Parameter on structural and piezoelectric properties of

Sr, La doped PZT Ceramics

S. Premkumara,b, N. N. Wathorea, V.L. Matheb

a Armament Research and Development Establishment, Pune, 411021, India. bDepartment of Physics, Savitribai Phule Pune University, Pune 411007, India.

[email protected]

Abstract:

Poling is necessary for domain reorientation and domain wall movement of ferroelectric ceramics to

exhibit piezoelectric effects. Optimization of poling parameters such as electric field, temperature and

time is important to align maximum domains in the direction of electric field. Effect of poling

parameters on structural and piezoelectric properties of Sr, La doped PZT ceramics were investigated

in this study. We have synthesized Sr and La substituted PZT ferroelectric perovskite solid solutions

having general formula Pb(1-x-y)SrxLay (ZrzTi(1z))O3 (PSLZT) with x =0.25 y =0.5 and z = 0.53, by

solid oxide method. SEM micrograph shown compact microstructure XRD analysis of sintered

PSLZT ceramics shown co-existence of ferroelectric tetragonal (T) and rhombohedral (R) phases.

Ferroelectric analysis shown square P-E hysteresis behavior. The inter-dependency among the poling

parameters was observed and hence simultaneous variation in parameters were studied to obtain

maximum piezoelectric properties. However, extent of poling was observed to be highly influenced

by temperature compared to poling field and time. At optimized poling temperature of 80oC

comparatively lesser poling field and time were required to obtain maximum value of piezoelectric

coefficients. X-ray diffraction studies of poled PSLZT ceramics indicated enhancement in

tetragonality with increase in poling temperature. At optimized poling condition piezoelectric charge

coefficient (d33) of 520 pC/N was achieved. This composition also exhibited better piezoelectric

voltage coefficient (g33) compared to other PZT based ceramics, at optimum poling condition, which

is useful for enhancement of the sensitivity of sensors.

Fig. 1 XRD of Poled PSLZT Fig. 2 SEM image of sintered PSLZT

Keyword: Poling, PSLZT, piezoelectric voltage coefficient (g33), ferroelectric domains, XRD

OP-01


18

Stability and electronic structure of bulk-like non-stoichiometric

ZnO clusters. Prashant V. Gaikwad

Department of Physics and Centre for Modeling and Simulation, Savitribai Phule Pune University,

Pune-411007, India

Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India

ABSTRACT

The effect of non-stoichiometry, on structural evolution of ZnO clusters is explored to enhance

fundamental understanding as well as to set a handle for structure tuned properties for applications. In

that direction, electronic structure and related properties of nearly stoichiometric and non-

stoichiometric clusters of ZnO having bulk-like wurtzite geometry (Fig. 1) are comparatively analysed

for structural evolution using density functional theory (DFT) based electronic structure calculations.

The effect of passivation is studied and a new parameter, average binding energy per atomic number

(ABE-number) is introduced to study stability of non-stoichiometric clusters.

The structural evolution is mapped on the basis of spin polarised electronic structure analyzed by site

projected partial density of states (l-DOS) and ABE-number (Fig. 2). Using cluster assembly route[1],

a new three- dimensional (3D) divacancy defect oriented structure is proposed using stable cluster

geometries of passivated clusters. This structure is named perforated allotrope linage (PAL) structure

on the basis of possibility of other stable structures having different degree of perforation. Thermal,

mechanical and dynamic stability of the structure in various materials is studied. The effect of non-

stoichiometry, during structural evolution for small to medium sized clusters, can enhance the

fundamental understanding about and, in principle, can set a handle to tune properties of the material

for applications.

References:

[1] Scott M. Woodley and Richard Catlow, Nature Materials, 7,937 (2008).

[2] Prashant V Gaikwad, Pradeep K Pujari, Sudip Chakroborty and Anjali Kshirsagar, J. Phys.:

Condens.Matter 29 (2017) 335501).

FIG. 1. (Colour online) Geometries of

unpassivated and passivated clusters of Zn-

atom centred non-stoichiometric ZnO clusters

up to 5 layers (centre atom considered as layer

1). O-atom centered clusters are similar where

Zn and O atoms have been interchanged and

passivation is done by appropriate fictitious

hydrogen atoms. The Zn, O and fictitious

hydrogen atoms H__ and H_ are represented by

magenta (larger), brown (small) and blue and

silver (tiny) balls respectively.

FIG. 2. Variation in ABE-number as a

function of ROF for (a) bare Zn-surfaced

(OA), (b) bare O-surfaced (OB), (c)

passivated O-surfaced (OC) and (d)

passivated Zn-surfaced (OD) ZnO

clusters. For comparison ABE-number for

bare (green diamond) and passivated

(olive open circle) stoichiometric clusters

are also incorporated from reference [2].

OP-02


19

Highly sensitive thermally grown Ag nanoparticles for the application of

surface enhanced Raman scattering.

Imran M. Shaikh and S. D. Sartale*

Thin Films and Nanomaterials Laboratory, Department of Physics,

Savitribai Phule Pune University, Pune 411 007, India.

*Corresponding author: [email protected]

Abstract:

When a Raman active molecule placed in between the vicinity or get adsorbed on the surface of the

metal nanoparticles, its Raman scattering intensity get enhanced, this phenomenon is called as surface

enhanced Raman scattering (SERS). SERS technique emerged as a powerful tool for analyzing and

detection of various Raman active molecules in trace amount due to its properties like highly sensitive

and finger printing of molecules. Ag nanoparticles gives large SERS enhancement compared to the

other plasmonic nanoparticles (Au and Cu) due to its narrow plasmonic band width in the visible

range [1]. In the present work we have grown Ag nanoparticles using simple cost effective spin

coating method. Ethanolic solution of AgNO3 is first coated on the glass substrate followed by the

reduction at 450 C in H2 environment. SERS activity of Methylene blue (MB) was investigated on

the spin coated Ag nanoparticles with different RPM. We have optimized the RPM so as to get

maximum SERS activity. We have also find the low concentration detection limit to show the

sensitivity and checked reproducibility of the SERS signal of the MB molecules using optimum SERS

substrate.

References

1. Moskovits, M., Surface-enhanced Raman spectroscopy: a brief retrospective. Journal of

Raman Spectroscopy, 2005. 36(6-7): p. 485-496.

OP-03



20

Transport Properties of Zigzag SnSe Nanoribbons

Aniruddha Kibey

Department of Physics, Savitribai Phule Pune University,

Pune ,411007, India

Abstract:

In this decade many new two dimensional materials such as phosphorene, transition metal

dichalcogenides etc. have been studied. Amongst these phosphorene, due to its bandgap of 1.88 eV

and high electron mobil-ity, has attracted a great deal of interest. Zigzag phos-phorene nanoribbon

devices exhibit negative differential resistance (NDR), which has many applications in various

devices. However, phosphorene nanoribbons have a high tendency to get oxidized, which to

degradation of performance of the device [1].

SnSe has similar geometric structure as phosphorene. Moreover, SnSe nanoribbons have a lower

oxidization rate as compared to phosphorene nanoribbons, making them better candidates for device

applications [2]. Hence it is proposed to study transport properties of SnSe nanorib-bons to check if

they exhibit NDR.

In this work transport properties of zigzag SnSe nano-ribbons of two different widths are calculated.

We have used the density functional theory non-equilibrium Greens function formalism (DFT-NEGF)

implemented in the Quantumwise Virtual Nanolab [3{5].

From our calculations we nd that a two-terminal de-vice made of zigzag SnSe nanoribbon shows

NDR. I will also present a comparative study of SnSe and phospho-rene nanoribbons.

FIG. 1: I-V curve for zigzag SnSe nanoribbon of 5 unit cell width

References:

[1] S. Koenig, R. Doganov, H. Schmidt, A. Castro-Neto, and B.Ozyilmaz, Appl. Phys. Lett., 104 ,

103106 (2014).

Yu Guo, Si Zhou, Yizhen Bai, and Jijun Zhao, ACS Appl. Mater. Interfaces, 9, 12013,(2017).

Atomistix toolkit version 13.8, quantumwise a/s (2015).

Virtual nanolab version 13.8, quantumwise a/s (2015).

M. Brandbyge, J.-L. Mozos, P. Ordejon, J. Taylor, and K. Stokbro, Phys. Rev. B 65, 165401 (2002)

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Low temperature Photoluminescence study of d-d transitions in

Mn-doped ZnSe nanocrystals Mohammed Abdul Haque1 and Shailaja Mahamuni1*.

1 Department of Physics, Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India

email: [email protected]

ABSTRACT

In this work, we have employed photoluminescence and photoluminescence excitation (PLE)

spectroscopy to study p-d mixing and d-d exchange interaction of Mn-doped ZnSe nanocrystals (NCs)

from room temperature through 10 K. Mn-doped ZnSe NCs of size about 5 nm with zinc blend crystal

structure are grown by the nucleation doping strategy. The doped-NCs reveal strong Mn-related

emission; surprisingly that shows red shift with the decrease in temperature. PLE spectra recorded at

10 K by fixing the Mn2+related orange emission reveals four different excitation features namely 4T1,

4T2, 4A1,

4E above 6A1 ground state of Mn2+. Crystal field parameter (Dq) and Racah parameters (B

and C) are calculated using these excitation features. Increased covalency of the metal-ligand bond

and the enhanced exchange interaction between different d-electrons is found. Increment in covalency

and exchange interaction is corroborated by the appearance of broad feature in electron spin

resonance spectroscopy.

References:

[1] J. K. Furdyna, J. Appl. Phys. 64 (1988) R29R64.

[2] N. Pradhan, D.M. Battaglia, Y. Liu, and X. Peng, Nano Lett. 7 (2007) 312317.

[3] S. Mahamuni, A.D. Lad, S. Patole, J. Phys. Chem. C. 112 (2008) 22712277.

[4] R. Viswanatha, D.M. Battaglia, M.E. Curtis, T.D. Mishima, M.B. Johnson, X. Peng,

Nano Res. 1 (2008) 138144.

[5] W. Chen, R. Sammynaiken, Y. Huang, J.O. Malm, R. Wallenberg, J.O. Bovin, J. Appl.

Phys. 89 (2001) 11201129.

[6] A. Hazarika, A. Layek, S. De, A. Nag, S. Debnath, P. Mahadevan, Phys. Rev. Lett.

110 (2013) 15.

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Sensing Behavior of B-N-C Monolayer towards Greenhouse Gas molecules:

DFT Study 1, 2 Manasi S. Mahabal; 2Mrinalini D. Deshpande

1. Department of Electronics Science, S. P. Pune University

2. Department of Physics, H.P.T. Arts and R.Y.K. Science College, Nasik, Maharashtra - 422 005,

India.

Abstract:

Graphene based materials have been widely explored for the fabrication of gas sensors because of

their atom-thick two-dimensional conjugated structures, high con-ductivity, and large speci c surface

areas. [1] In 2007, Novoselov and co-workers reported graphene-based sens-ing devices for detecting

single molecules of gases. [2] This pioneering work inspired research on graphene based gas sensors.

Similar to graphene monolayer, h-BN sheet could serve as an excellent substrate for high-

performance graphene electronics. Keeping in mind the similarities between the atomic structures of

these sys-tems (the mismatch between the lattice constants of the materials is only 2%) and the

radically di erent elec-tronic properties, the growth of boron doped graphene and hybrid boron-

carbon-nitride (B-C-N) materials with tunable electronic characteristics has been attempted.[3{ 5]

Among the various phases with the boron doping in graphene BC3 is the most stable phase.[6] For BN

doped graphene, BNC2 is the most stable phase.[7] Recent few theoretical and experimental work[8,

9] have shown that the following to graphene, BC3 and BNC2 sheet should be the potential candidates

in the area on gas sensors. It is also seen that the sensing mechanism can be improved by doping

metal elements. [9]

This work presents the Density Functional Theory (DFT) based study for sensing characteristics of a

graphene like boron carbide (BC3) and BN doped car-bide monolayer (BNC2) towards the various

gases such as CO, CO2, NO, NO2, NH3, H2O, and H2S. Among the gas molecules, CO2 is predicted to

be weakly ad-sorbed on the graphene-like BC3 sheet, whereas the NH3 gas molecule shows a strong

interaction with the BC3 sheet. For BNC2, the gas adsorption capability improves as compared to

graphene and BC3. NH3 molecule has strong interaction on BNC2 monolayer. Overall the in-teraction

of NH3 molecule on BNC2 monolayer increases by 33% as compared to BC3 sheet. Further the doping

with Al atom in BC3 and BNC2 sheet it is found that the electronic properties changes with respect to

the pristine monolayer. CO2 adsorption on Al doped BNC2 mono-layer is found to be the dissociative

nature. It is seen that energy gap is sensitive to the doping element as well as adsorption of gas

molecules, thus o ering the possi-bility for future gas sensors based on pristine BC3 and BNC2

monolayer as well as doped BC3 and BNC2 mono-layer.

References:

P. Miro, M. Audi red, T. Heine, Chem. Soc. Rev., 43, 6537-6554 (2014).

F. Schedin, A. K. Geim, S. V. Morozov, E. W. Hill, P. Blake, M. I. Katsnelson, and K. S. Novoselov, Nat. Mater., 6, 652655 (2007).

N. Kumar, K. Moses, K. Pramoda, S. Shored, A. Mishra, U. Waghmare, A. Sundaresan, and C. N. R. Rao, J. Mater. Chem. A, 1, 5806-5821 (2013).

C. N. R. Rao, K. Gopalkrishnan, ACS Appl. Mater. Inter-faces, 9, 19478-19494 (2017).

C. N. R. Rao, K. Gopalkrishnan, and U. Maitra, ACS Appl. Mater. Interfaces, 7, 7809-7832 (2015).

H. Tanaka, Y. Kawamataa, H. Simizua, T. Fujitaa, H. Yanagisawaa, S. Otanic, and C. Oshima, Solid State Com-munications, 136, 22-25 (2005).

J. Zhu, S. Bhandary, B. Sanyal, and H. Ottosson, J. Phys. Chem. C, 115, 1026410271 (2011).

X. Wang, G. Sun, P. Routh, D-H Kim, W. Huang, and P. Chen, Chem. Soc. Rev. 43, 7067-7098 (2014).

J. Beheshtian, A. A. Peyghan, and M. Noei, Sensors and Actuators B, 181, 829 (2013)

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Synthesis of Iron Oxide Polymorphs by Thermal Plasma and Their

Application in the Development of Mechanical Vibration Damper

Suyog Rauta, S. Premkumarc, Nilesh Kanhea,b, Sudha Bhoraskara and Vikas Mathea aDepartment of Physics, Savitribai Phule Pune University, Pune- 411 007

bDepartment of Physics, Arts, Commerce and Science College, Satral, Ahmednagar- 413 711 cArmament Research and Development Establishment, Pashan, Pune- 411 021

Presenting Author: [email protected]

Abstract:

Iron oxide possesses different polymorphs such as magnetite (Fe3O4), maghemite (-Fe2O3), hematite

(-Fe2O3) etc. Preparation of these phases of iron oxide nanoparticles by conventional chemical route

is very cumbersome process which takes large time and efforts. Thermal plasma synthesis route

provides a better alternative to conventional methods and provides high yield of nanoparticles.

Current method employed for the synthesis process allows control over different parameters such as

oxygen partial pressure, ambience of the reactor, operating pressure and power etc. By understanding

the difference between iron oxide polymorphs one can easily tune the synthesis conditions. The

magnetite (Fe3O4) and maghemite (-Fe2O3) polymorphs were synthesized by using thermal plasma

system with optimum synthesis parameters.

Fig. 1: X-ray diffraction pattern for standard and as synthesized iron oxide nanoparticles

Further the iron oxide polymorph with higher magnetization i.e. magnetite (Fe3O4) were mixed in a

liquid to obtain dispersion. The iron oxide nanoparticles were loaded in engine oil with variable

concentrations. The main aim to obtain a good dispersion was to improve viscosity of the liquid which

further increases in presence of external magnetic field. A prototype was designed and developed in

laboratory to check the performance of the fluid prepared. Further, the fluid so obtained was used to

develop mechanical vibration damping unit where shock stroke is generated using special mechanical

arrangement. The shock stroke generated found to damp significantly in presence of magnetic field.

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Fig. 2: Graph showing actual damping achieved with iron oxide nanoparticles (60% solid

loading)

References

[1] S. Laurent, D. Forge, M. Port, A. Roch, C. Robic, L. Vander Elst, et al., Magnetic iron oxide

nanoparticles: synthesis, stabilization, vectorization, physicochemical characterizations, and

biological applications, Chem. Rev.108 (2008) 20642110, https://doi.org/10.1021/cr068445e.

[2] S.A. Raut, N.S. Kanhe, S.V. Bhoraskar, A.K. Das, V.L. Mathe, Thermal plasma processed ferro-

magnetically ordered face-centered cubic iron at room temperature 163913 (1-6) J. Appl. Phys. 116

(2014), https://doi.org/10.1063/1.4899244.

[3] S.A. Raut, P.R. Mutadak, S. Kumar, N.S. Kanhe, S. Huprikar, H.V. Pol, D.M. Phase, S.V.

Bhoraskar, V.L. Mathe, Single step, phase controlled, large scale synthesis of ferrimagnetic iron oxide

polymorph nanoparticles by thermal plasma route and their rheological properties, J. Magn. Magn.

Mater. 449 (2018). doi:10.1016/j.jmmm.2017.09.056.

https://doi.org/10.1021/cr068445ehttps://doi.org/10.1063/1.4899244


25

Metallic and antiferromagnetic fixed points from gravity

Chandrima Paul

Department of Physics, Sikkim University,

6th Mile , Gangtok 737102, India

We consider SU(2) U(1) gauge theory coupled to matter field in adjoints and study RG group

group flow. We constructed Callan Symanzik equation and subsequent functions. With the

application of superpotential method we study the fixed points. We obtain the expression of the

fields near fixed points. We found there exist a nontrivial fixed point, showing

antiferromagnetic behaviour. We have also checked the stability of metallic fixed point and

have shown that metallic phase develops an instability if certain parametric conditions are

satisfied.

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Nanostructured CoFe2O4 micro-granules for Adsorption of Pb(II) from

Aqueous Solution S. M. Ansari 1, D. Sen2, and Y. D. Kolekar1,

1Department of Physics, Savitribai Phule Pune University, Pune-411007, India 2Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085, India


Abstract:

We report a one-step, environment friendly, low temperature synthesis of efficient, cost effective, and

regenerated nano-structured CoFe2O4 micro-granules and demonstrate their applicability in removal of

heavy metal ion (i.e. lead, Pb+2) from aqueous solutions. Inherent physiochemical and magnetic properties

were investigated in detail. Refinement of XRD data and Raman spectroscopic studies confirm the cubic spinel

phase. Electron microscopy and small-angle X-ray scattering revealed narrow particle-size distribution as well

as well-defined spherical morphology without agglomeration. Overall adsorption of Pb+2 ions occurs

through a multilayer adsorption mechanism as studied under various models. Maximum removal

efficiency of 97.76 % with monolayer adsorption capacity of 1951.98 mg/g was observed for nano-

structured CoFe2O4 micro-granules. Assessment of adsorption kinetics and isotherm for pristine

magnetic materials suggests their potential application as effective adsorbent towards removal of Pb+2

ions and other heavy metal ions from water for environmental applications.

Introduction and experimental:

Globalization, rapid developments in industrialization, urbanization and population have largely

contributed to the severe pollution of water, air and soil. Among these, drinking safe and clean water

has become the major concern for practical utility. Most of industries are producing wastewater that

contain harmful and toxic metal ions. Heavy metal ions are one of the major harmful contaminants in

water [1]. Moreover, the contamination of water with toxic metal ions (Cr 3+, Ni2+, Co2+, Cu2+, Cd2+,

Ag2+, Hg2+, Pb2+ and As2+ ) becoming a severe environmental and public-health problem [2].The major

concern with respect to heavy metals is their ability to accumulate in the environment and cause

heavy-metal poisoning. Therefore, to counteract it, various processes like chemical, physical and

biological have been developed to prevent the pollution [3]. Among these processes, adsorption is one

of the widely used process for the removal of heavy metal ions and is considered to be easy to operate

and cost-effective [1]. Till-date there are number of adsorbents used for the removal of heavy metal

ions, and hence synthesis of novel adsorbents is of great interest in water treatment technology. In this

context, various magnetic materials can be used as adsorbents [3] and cobalt ferrite (CFO) with a

cubic spinel structure exhibit the excellent chemical stability and moderate saturation magnetization

[4]. Therefore, here, nano-structured CFO micro-granules were prepared using spray drying process

and adsorption studies were then conducted by mixing 20 mg of magnetic adsorbents into 50 mL of

Pb+2 ion (20 mg/L) aqueous solutions.

Results and discussion:

Fig.1(a) depicts the morphology of pristine powder, which reveal the presence of spherical shape

granules with a slight polydisperse distribution. Moreover, the close examination of micro-granules

demonstrates that granules were made up of subunit particles. Small angle x-ray scattering (SAXS)

profile (inset of Fig1-(a)) strongly suggest that CFO possess nanostructured granules.

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Fig 1 (a) SEM image along with SAXS profile (inset) (b) X-ray diffraction along with Rietveld-fitting

(c) Raman spectra and (d) regeneration studies of nano-structured CFO micro-granules.

Fig. 1(b) shows the the Rietveld-refined plots of X-ray diffraction data for CFO and refinement of the

XRD data confirms the single phase, cubic inverse spinel structure for pristine sample. All the peaks

were indexed according to the cubic spinel ferrite (JCPDS card no.221086) structure with a space

group Fd3m (227). Phase purity is further supported with Raman spectroscopy analysis (Fig. 1(c)).

Group theory predicts that there are five Raman active modes, i.e., Ag + Eg + 3T2g present in the cubic

spinel. Thus, all the five Raman vibrations are assigned to the vibrational mode of Fd3m space group.

No any additional peaks were found that supports the high purity of the sample. Furthermore, time

dependent removal efficiency (not shown) of Pb +2 ions were studied. It is noticeable that the

maximum removal efficiency was observed to be 97.76 % along with maximum adsorption capacity

(qe,exp) of 48.88 mg/g for nano-structured CFO micro-granules. The elemental mappings determined

by EDS after the adsorption experiments shows the homogeneous distribution of Pb+2 adsorbed on the

MNPs and with this, the adsorption of Pb+2 by the MNPs was confirmed. Importantly, it is observed

that the adsorption capacity of magnetic adsorbent almost kept a constant regeneration of 99% in five

cycles, which indicates that the interactions between donor sites on the surface of magnetic adsorbents

and Pb+2 ions are reversible. In conclusion, present results predict that no strong bonds were created

between the surface of magnetic absorbent and the Pb+2 ions. Thus, it can be further be deduced that

there is no chemical redox reaction occured during the whole process of adsorption/desorption.

Conclusion:

Novel magnetic adsorbents were synthesized successfully by spray drying process. Overall the

adsorption of Pb+2 ions occurs through a multilayer adsorption mechanism for nano-structured CFO

micro-adsorbents. Appropriate characteristic of the magnetic CFO adsorbents such as high adsorption

capacity, reusability, easy synthesis, easy separation, and environmental friendly compositions make

them suitable alternatives to the well-known and widely used adsorbents for the removal of heavy

metal ions from aqueous samples. The proposed magnetic nano-structured CFO micro-granules were

successfully applied for the removal of other heavy metals ions from aqueous solutions and complex

industrial wastes.

Reference

1. C. Santhosh, P. Kollu, S. Felix, S. K. Jeong and A. N. Grace, RSC Adv., 2015,

2. B. Viltuznik, A. Kosak, Y. L. Zub, A. Lobnik, J Sol-Gel Sci Technol. 2013, 68, 365-373.

3. D. Zhang, S. Wei, C. Kaila, A. B. Karki, D. P. Young and Z. H. Guo, Nanoscale., 2010, 2, 917-919.

4. S. M. Ansari, D. Sen, Y. D. Kolekar, C.V. Ramana, , ACS Biomater. Sci. Eng. 2016, 2, 2139-2152.


28

Enhancement of HER and OER Activity

Through Vacancy Defect and Functionalization in Stable PdS2 Monolayer Deepashri Saraf

[email protected]

Department of Physics, Savitribai Phule Pune University

Ganeshkhind, Pune 411007, India

In our study of 1T-PdS2 monolayer functionalized with S-monovacancy, C and N-adatom, we

performed systematic electronic structure calculations within density functional theory framework as

implemented through VASP package [1]. Our aim was to assess the potential of these monolayers for

photocatalytic water splitting [2]. For the weak interactions involved in the computation upon the

addition of dopants like carbon and nitrogen and introduction of mono-vacancy, we have used

PBE+D3 method with Grimme vdW corrections as implemented in VASP [3]. Upon examination of

density of states and optical response of these monolayers [4], we observed that the functionalization

causes decrease in the band gaps of the PdS2 monolayer due to the presence of defect states in

the electonic gap. Also, the monolayer acquires weak magnetic nature with the inclusion of N-adatom.

All the functionalized monolayers show the highest absorption peak within visible range. The work

function calculations show that there is no significant change in the work function of the monolayer

due to functionalization. We also calculated the adsorption energies of different intermediates H, O,

OH and OOH on top of the functionalized monolayers, to further calculate the reaction coordinates

in HER and OER as given by Nrskov et al. [5]. Amongst all the considered cases, S-monovacancy

functionalization turns out to be the best possible case for HER whereas that for OER, it is N-adatom

functionalization. These theoretical calculations can lead to a better understanding of how the

functionalization can affect the HER-OER activity on PdS2 monolayer, which can provide guidelines

for an efficient experimental investigation.

ACKNOWLEDGEMENT DS would like to acknowledge Dr. Sudip Chakraborty, Prof. Anjali Kshirsagar and Prof. Rajeev

Ahuja for this work.

References [1] G. Kresse, and J. Furthmuller, Phys. Rev. B, 54, 11169 (1996).

[2] J. Rossmeisl, A. Logadottir and J. K. Nrskov, Chem. Phys., 319, 178 (2005).

[3] S. Grimme, J. Antony, S. Ehrlich and S. Krieg, J. Chem. Phys., 132, 154104 (2010).

[4] M. Gajdos, K. Hummer, G. Kresse and J. Furthmuller, F. Bechstedt, Phys. Rev. B, 73, 045112, (2006).

[5] J. K. Nrskov, J. Rossmeisl, A. Logadottir, L. Lindqvist, J. R. Kitchin, T. Bligaard, and H. Jonsson, J. Phys.

Chem., 108, 17886-17892 (2004).

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Observation and manipulation of magnetic domains in sol gel derived thin

films of zinc substituted Nickel ferrite

Ashwini A Datar and Vikas L Mathe

Department of Physics, Savitribai Phule Pune University, Ganeshkhind, Pune 411 007.


Abstract:

The magnetic materials find innumerable uses hence a thorough knowledge and understanding of the

microstructures is necessary. This can be well understood if we are able to correlate the effects of the

external stimuli on the magnetic domain behavior. Exploring the static and dynamic behavior of

magnetic domain and domain wall is an important issue due to its wide range of technological

applications in the area of memory[1,2] and logic devices [3,4]. For an improved performance of such

devices, fast and appreciable response of domain and domain wall motion is expected [5,6]. The

above requirement can be probed by using the magnetic force microscopy (MFM). MFM is

considered as a state of art tool, which can be used to extract magnetic domain alignment even at the

nanoscale.

Knowledge of magnetic domain structure in spinel ferrite thin films is an important issue from the

view point of fundamental understanding and technological applications. Nature of magnetic domain

in thin film is sensitive to saturation magnetization, magnetostriction, exchange stiffness, magneto-

crystalline anisotropy, surface anisotropy, film stress etc. Magneto-static energy and exchange energy

are the key parameters which decide the nature of mag

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