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Motivation
Results
• Successful incorporation of Mg on Cu2O thin 7ilms by MOCVD with a thickness below 100 nm; • FTIR con7irms the presence of Mg-‐O bonds; • Elemental quanti7ication by EDS shows Mg/Cu ratios 2 to 3 times lower than Mg molar mass in the original solution;
• The predicted changes in transparency [Nolan 2008] were not obtained by this cation incorporation; • For 7ilms with high Mg content, the resistivity is reduced 7ive times, from 53 Ω.cm to 11 Ω.cm. The causes can be attributed to:
Ø Different microstructure: Larger grains – Higher mobility. Ø Higher amount of copper vacancies – More charge carriers.
Conclusions
References : Nolan, M. Chemistry of Materials, 2008. 20(17): p. 5522-5531. http://www.doyouknow.in/Articles/images/201112231235452410290.png
Magnesium-doped Cuprous Oxide (Mg:Cu2O) thin films as a transparent p-type
semiconductor oxide J. Resende1,2*, C. Jiménez1, N. D. Nguyen2, J. L. Deschanvres1
1 Laboratoire des Matériaux et du Génie Physique, Univ. Grenoble Alpes 2 SPIN Lab, Department of Physics, University of Liège
O Cu
Mg
Reduced Cu-‐Cu interactions
Larger band gap
Higher transparency
Higher p-‐type conductivity
Cu2O cubic structure
Experimental
MOCVD scheme
Precursors: Cu (acac)2 c=0.02 mol.L-‐1 Mg (acac)2 c= 0 -‐ 0.01 mol.L-‐1
Solvent: Butanol; Deposition: T=350 ºC; t=60 min; rate=2 ml.min-‐1
Carrier gas: Ar 5 L.min-‐1 Acceleration gas: O2 4 L.min-‐1 Annealing Treatment: 1 hour under Air; T= 250ºC
Optical Appearance SEM
Transmittance Electrical Properties
Mg:Cu2O thin &ilms deposited on glass and silicon
Visible Transmittance around 50% Eg ~ 2,2eV
Decreasing behavior of sheet resistance and electrical resistivity with increasing content of Mg P-‐type conduction con&irmed by Hall Effect
FTIR
Mg-‐O bond detected at 436 cm-‐1
Raman
Cubic Cu2O phase detected
Mg/Cu in
solution (%)
Mg/Cu in
Bilm (%)
Thickness
(nm)
0 -‐ 86
5 2.5 45
10 3 97
25 7 52
50 20 77
EDS
Mg detection by EDS and Mg/Cu ratio quanti&ication
Mg/Cu molar ratio: 0% 5% 10% 25% 50%
Larger grains with the increase of Mg content; Thickness below 100 nm