Thin film studies have made tremendous advances in the last decade due to industrial demand for reliable and sustainable energies. The thin film solar energy conversion devices have, therefore become of vital importance. Therefore more attention has been paid to direct conversion of sunlight into electricity using the photovoltaic properties of suitable materials. CdS and CdSe are two very important wide band gap semiconductors among the II-VI semiconductors and finds wide applications in optoelectronics, such as non-linear optics, visible-light emitting diodes and lasers. However, for some optoelectronic applications it is important to tune the emission wavelength. The tunability of band gap can be achieved through composition modulation, for example, alloyed II-VI semiconductor ternary of CdS1-xSex with continuously tuned band gap is possible. To realize these applications, it is of primary importance to grow high quality CdS1-xSex (0.0 x 1.0) thin films and characterize them for fundamental properties like PEC characterization, structural, morphological, electrical and optical properties in order to improve the performance of the devices.