The effect of lasing energy of Q –Switched Nd: YAGlaser (1064 nm) on the structural and optical properties of Zinc sulfide nanofilms synthesized by pulsed laser deposition has been studied. The prepared films are to be employed in the preparation of p-ZnS/n-Si photodiode. Laser pulse energies of (600, 750, and 900) mJ with fixed number of pulses of 700 and pulse duration of 6 Hz have been utilized. The patterns of X- ray diffraction confirm that all the films have polycrystalline and hexagonal structure with three notable preferred planes of (100), (002), and (101). The intensities of the notable peaks increase as the laser energy increases. The crystallite size of the preferred orientation (002) plane of (ZnS) films has been decreased as lasing energy increases to be 28 nm at 900 mJ. The films have a transmission of (70-90%) in visible and NIR region of solar spectrum. The optical band gap increases with increasing of lasing energyto be 3.9 eV at 900 mJ of lasing energy. The efficiency of the p-ZnS/n-Si diode has been calculated to be 14.8 % using IV characteristic measurement.

(ZnS) Films, Crystalline Structure, Optical, Solar Cell.