Number of Laser Pulses Influence on Optical Properties of Pulse Laser Deposited ZnS Thin Films

Abstract

In present work four samples of ZnS thin films deposited on glass substrate using pulse laser deposition method with different number of laser pulses, the effect of the number of laser pulses on the optical properties of ZnS thin films was studied. Q-Switched Nd: YAG laser with the fundamental wavelength 1064 nm, laser pulse energy of 100 mj with fixed pulse repetition rate of 2 Hz were used, and varied number of (10, 15, 20 and 25) pulses . The target to the substrate distance and angle were kept fixed. The film thicknesses were measured using FESEM measurement tool. Thickness of the deposited ZnS thin films was found to be dependent on the number of laser pulses used. The transmission spectra in the region (532 to 915) nm were recorded and was showed that for each ZnS thin film the transmission spectrum is unique. The refractive indices of all samples were determined. Transmission percentage were found to be varied from (0.4 to 0.62) %, absorption coefficients were found to be varied from (28.287 to 7.300) *10³ cm^-1 and the refractive indices, depending on the film thickness and the wavelength were in very good agreement with the literature.