Study on optical investigations and DC conduction mechanism in polycrystalline chalcogenide (Cd, Zn) semiconductor films grown by screen-printing method

Abstract

The use of thin films of polycrystalline chalcogenide semiconductors has attracted much interest in an extensive variety of applications in various electronic, optoelectronic and photovoltaic devices due to their favorable electrical and optical properties. In this paper II–VI compound (cadmium and zinc chalcogenide) binary and ternary semiconductor thick films were deposited on ultraclean glass substrates by screen-printing method followed by sintering process. The polycrystalline nature of these films was confirmed by X-ray diffraction studies. The stoichiometry of the films was confirmed using energy dispersive X-ray analysis. The optical band gap and absorption coefficient of the films were determined by reflectance measurement in wave-length range 350–900 nm using UV/Vis spectrophotometer. The conduction mechanism in these films were studied by measuring the dark DC electrical conductivity in 300–400 K temperature range by using standard two probe method in vacuum. It was observed that conductivity of these films increases with increase in temperature. The linear nature of plot ln σDC against 1000/T for these films indicates that conductivity of films is in close agreement with the Arrhenius relation and conduction in these films is through thermally activated process.