Direct synthesis of quaternary Cd(Zn, S)Se thin films: Effects of composition

• Published in: Materials science in semiconductor processing 2017-11, Vol.71, p.447-453
• Main Authors: Chavan, G.T., Pawar, S.T., Prakshale, V.M., Pawar, S.M., Ezugwu, S., Chaure, N.B., Kamble, S.S., Maldar, N.N., Deshmukh, L.P.
• Format: Article
• Language: English
• Subjects: Conductivity; EDS; Quaternary thin films; SEM; XRD
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2017.09.005

In the present communication, the binary CdSe and quaternary Cd1-xZnxSe1-ySy (0 ≤ x = y ≤ 0.35) thin films were synthesized using a chemical bath deposition. Thin film deposition was carried out at the optimized conditions (pH = 10 ± 0.1, deposition temperature = 70 ± 0.1°C, deposition time = 100min and substrate rotation speed = 65 ± 2rpm). X-ray diffraction studies confirmed hexagonal-wurtzite crystal structure with the formation of quaternary Cd(Zn, S)Se phase along with binary CdSe, CdS, ZnS and ZnSe, phases of the as-grown Cd1-xZnxSe1-ySy thin films. Elemental analysis showed presence of Cd2+, Zn2+, S2- and Se2- in the deposited films. Fourier transform infrared spectroscopy shown the bands at 911.15cm−1 – 901.62cm−1 which are assigned to the stretching frequency of Cd–Se bond. Scanning electron microscopy show transformation of the microstructure from globular crystallites to a rhomboid flake like network. The electrical conductivity was typically ≈ 10−7Ω−1 cm−1. At low temperatures, the conduction was by variable range hopping, and this changed to thermally activated grain boundary dominated conduction for T > 350K.