Synthesis and characterization of Cd1-xPbxSe (0≤x≤1) thin films deposited by chemical bath for photovoltaic application

Cd1-xPbxSe (0≤ x ≤ 1) thin films with values of x = 0, 0.2, 0.4, 0.5 and 1, have been deposited by chemical bath technique for photovoltaic application. The deposition temperature, time and pH of the reactive solutions were 80 o C, 150 min and 11 respectively. The XRD results confirmed the polycrystalline nature of all the films. It also showed that all the films exist in face centered cubic structures. There were no pure phases of CdSe and PbSe identified in the XRD results of the ternary compounds. The average grain sizes determined for each sample were found to be between 10.503, and 14.113 nm and their corresponding lattice constants were found to range from 0.605 and 0.6128 nm. The dislocation densities were also found to decrease with increasing lead content and ranged between 9.065×1014 and 5.021×1014 m2 . The EDX analysis conducted confirmed the deposition of Cd1-xPbxSe thin films. It was also observed that with the increase in lead content in the CdSe crystal lattice host, the grain sizes and intergranular spacing increased. The band gaps were found to decrease with increasing lead content from 1.80 to 1.38 eV, which are well within the optimum range for photovoltaic application.