Dependence of optical, structural and electrical properties of ZnxCd1-xS thin films prepared by co-evaporation on the composition for x=0-1

Thin films of zinc cadmium sulphide - a ternary compound intended to be used in solar cells - are prepared by co-evaporation. The films are prepared at room temperature, in a vacuum better than 10(-5) Torr. The composition of these films is varied from x = 0 to x = 1 in the compound ZnxCd1-xS. The structural, optical and electrical properties have been investigated as a function of x. The direct band gap varies from 2.415 eV to 3.41 eV for x = 0 to x = 1 respectively. The crystal structure is found to be hexagonal (Wurtzite) for 0 <= x <= 0.8 and cubic zinc-blende for x > 0.8. The lattice constants decrease and the optical bandgap increases with the increase in the value of x. The resistivity of the ZnxCd1-xS films is found to decrease from 3.6 x 10(4) Omega cm for x = 0 to 69.5 02 Omega cm for x = 0.3 and again increases beyond this range to a Value of 6.3 x 10(3) Omega cm for x = 1.0.