Supplementary information

Highly Conductive and Flexible Fiber for Textile Electronics Obtained by Extremely Low-Temperature Atomic Layer Deposition of Pt

Jaehong Leea†, Jaehong Yoona†, Hyun Gu Kimb, Subin Kanga, Woo-Suk Ohc, Hassan Algadia,

Saleh Al-Sayarid, Bonggeun Shongc, Soo-Hyun Kime, Hyungjun Kima, Taeyoon Leea*, and

Han-Bo-Ram Leeb*

aSchool of Electrical and Electronic Engineering, Yonsei University,50 Yonsei-ro,

Seodaemun-Gu, Seoul, 03722, Republic of Korea, bDepartment of Materials Science and

Engineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012,

Republic of Korea, c Department of Chemistry, Chungnam National University, 99 Daehak-

ro, Yuseong-gu, Daejeon, 34134, Republic of Korea, dPromising Center for Sensors and

Electronic Devices, Najran University, Najran, 11001, Saudi Arabia, eSchool of Materials

Science and Engineering, Yeungnam University, 280 Daehak-ro, Gyeongsan-si, Gyeongbuk,

38541, Republic of Korea

†These authors contributed equally to this work

*Address correspondence to:

Taeyoon Lee; E-mail: taeyoon.lee@yonsei.ac.kr

Han-Bo-Ram Lee; E-mail: hbrlee@inu.ac.kr

Figure S1. Schematic illustration of the commercial ALD chamber with 4-inch capable stage

used for the low temperature Pt ALD.

Figure S2. (a) Molecular structure of the HDMP precursor and (b) photograph showing the

precursor-included bottle at room temperature

Figure S3. XRD spectra of Pt films deposited by ALD using the HDMP precursor at the

deposition temperatures of 200, 250, and 300 °C. A metallic Pt(111) diffraction peak was

observed at 40.013° for all the Pt films deposited at the various temperatures.

Figure S4. DFT-calculated geometries of the critical points along the reaction coordinate for

the adsorption of the two Pt precursors.

Figure S5. (a–b) Typical SEM image (a) and the corresponding EDS mapping image (b) of

the conductive cotton fiber fabricated by the low temperature Pt ALD. The EDS mapping

image shows that the Pt layer is uniformly deposited onto the 3D complex structure of the

cotton fiber. (c) The EDS spectrum of the conductive cotton fiber coated with the Pt layer.

Figure S6. Typical SEM images showing the Pt layer deposited on the surface of cotton

fibers by ALD with the HDMP precursor and O2 gas. The continuity and conformality of the

Pt layer were maintained regardless of the number of ALD cycles.

Figure S7. Photographs of LED connected to the power supplier using the conductive cotton

fiber before (a) and after (b) applying external voltage of 3 V, indicating that the conductive

cotton fiber has excellent electrical properties.

Figure S8. Thermogravimetric analysis (TGA) of the conductive cotton fiber according to

the number of ALD cycles. The temperature increased from 30 °C to 600 °C at a rate of 10

°C/min. The small reduction in the weight percentage of the conductive fiber around 100 °C

indicates the evaporation of the residual moisture in the fiber. The cotton fiber was

decomposed around 200 °C.

Figure S9. Schematic illustration showing the fabrication process of the large-area textile

pressure sensor array on a fabric. After coating the cotton fiber with Pt through the low-

temperature ALD and a PDMS coating on the surface of the conductive fiber, the textile

pressure sensors were integrated into a fabric by simply sewing the PDMS-coated conductive

fibers perpendicularly onto the fabric.

Figure S10. Photograph showing the female sitter on the fabric including textile pressure

sensor arrays of 7 × 8 array configuration. Pressure distribution generated by the sitter can be

effectively detected by using the textile pressure sensor arrays in the fabric.

Figure S11. Capacitive response mappings of the 56-pixel textile pressure sensor array

against two sitters who have around (a) 60 kg and (b) 100 kg. The response result of the array

shows that the textile pressure sensor array can clearly distinguish the weight and body shape

of the sitter by the intensities and distribution of the capacitive responses.

Supplementary Video 1. The movie showing the operation of a light-emitting diode (LED)

using the conductive cotton fibers fabricated by low-temperature ALD of Pt.