Synthesis and characterization of F-doped CdS thin films by spray pyrolysis for photovoltaic applications

Asimple and inexpensive spray pyrolysis method has been employed to synthesis a reproducible pure and F:CdS thin films onto a pre-heated glass substrate. The x-ray diffraction studied reveals that the sprayed pure and F:CdS films exhibit cubic structure. The optical parameters of the sprayed pure and F:CdS films such as the linear refractive index n as well as the optical band gap, E-g were evaluated as a function of the F doped content. The dispersion parameters of the sprayed pure and F:CdS films were used to determine the nonlinear optical susceptibility, chi((3)) and non-linear refractive index n(2) as a function of the F doping content in CdS. The sprayed 8 wt% F:CdS thin film exhibit a highest values of the bsorption coefficient and optical conductivity as compared to other films. Thus, the concentration of 8 wt% F:CdS has been chosen to fabricate the Al/p-Si/F:CdS/Au heterojunction. The addition of fluorine to the CdS films raises the efficiency of the fabricated heterojunction from 1.92 to 2.63%.