In this paper, we report electrosynthesized cadmium sulfide (CdS) thin films for the electron beam irradiation and solar cell application. Deposited and irradiated CdS thin films are characterized for their structural, surface, morphological, and electrical properties by XRD, FE-SEM, and photoelectrochemical cell measurement. We have confirmed that the optical and photoelectrochemical properties can be improved by irradiation treatment. This work is useful for surface tailoring and providing a novel approach to improve photoelectrochemical properties of nanostructured CdS thin films for the promising applications in nano system devices to convert solar energy. The maximum efficiency and fill factor are found to be 1.8% and 0.49 at 25 kGy, respectively.