A novel route to synthesize Cd1-xPbxSe thin films from solution phase

Chemosynthesis of technologically important Cd1-xPbxSe thin films with varying lead concentrations (0 <= x <= 1) has been developed with the objective of studies related to growth kinetics, physical, microscopic, compositional, structural, optical and electrical characteristics, and the related alteration in these, due to the incorporation of Pb in CdSe. The developed method is based on the reaction between tartarate complexes of Cd2+ and Pb2+ with sodium selenosulphate in an aqueous alkaline medium at 278 K. The optimum preparative parameters, such as reactant concentration, pH, deposition temperature and rate of substrate agitation, have found to influence quality and thickness of films significantly. Attempts were made to optimize the parameters to obtain good quality films. The 'as deposited' films were characterized by XRD, AAS, EDAX, SEM, and optical and thermoelectric techniques. The XRD study indicates polycrystalline nature in hexagonal (for 0 <= x <= 0.5) and cubic (for 0.6 <= x <= 1) phases. The effect of lead composition x on properties such as optical band gap, absorption coefficient and dark dc electrical conductivity has also been studied. It has been observed that the films constitute solid solutions with hexagonal and cubic structures in low lead composition and high lead composition, respectively.