Quaternary schematics for property engineering of CdSe thin films

Publication date: 31 December 2017
Source:Applied Surface Science, Volume 426
Author(s): G.T. Chavan, S.T. Pawar, V.M. Prakshale, A. Sikora, S.M. Pawar, N.B. Chaure, S.S. Kamble, N.N. Maldar, L.P. Deshmukh
The synthesis of quaternary Cd1-xZnxSySe1-y (0≤x=y≤0.35) thin films was done through indigenously developed chemical solution growth process. As-obtained thin films were subjected to the physical, chemical, structural and optical characterizations. The nearly hydrophobic nature of the as-deposited films except binary CdSe was observed through the wettability studies. The colorimetric studies supported a change in physical color attributes. The elemental analysis done confirmed the formation of Cd(Zn, S)Se and the chemical states of constituent elements as Cd²⁺, Zn²⁺, S²⁻ and Se²⁻. Structural assessment suggested the formation of the polycrystalline quaternary phase of the hexagonal wurtzite structure. The Raman spectroscopy was also employed for the confirmation studies on Cd1-xZnxSySe1-y thin films. Morphological observations indicated microstructural transformation from an aggregated bunch of nano-sized globular grains into a rhomboid network of petal/flakes like crystallites. The atomic force micrographs (AFM) revealed the enhancement in the hillock structures. From advanced AFM characterizations, we observed that the CdSe thin film has leptokurtic (Sku=3.23) surface, whereas, quaternary Cd(Zn, S)Se films have platykurtic (Sku<3) surface. The orientation of the surface morphology was observed through the angular spectrum studies. The optical absorption studies revealed direct allowed transition for the films with a continuous modulation of the energy bandgap from 1.8eV to 2.31eV.



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