INVESTIGATION OPTICAL PROPERTIES OF CUZNSNSTHIN FILMS PREPARED BY PULSE LASER DEPOSITION

Abstract

The prepared samples of thin-film by laser ablation method were achieved. Powders of (CZTS) copper (Cu), zinc (Zn), tin (Sn) and Sulfur (S) of and then compressing by approximately 3 tons in Pellets form. The samples were ablated by using Neodymium-YAG laser with different laser energies (400mJ, 500mJ, 600mJ, 700mJ, 800mJ) and number of pulses (300)pulse, frequency (6Hz)and wavelength(1064) nm obtained the plasma plume at 10-5mbar pressure. Results indicate the optical properties of the films, which were prepared ,have been determined by using the optical transmittance measurements in the spectral region from 400 to 1000 nm. Transmittance results were upper than 90% which make these films suitable for sensor applications.. The optical energy gap of Cu2ZnSnS4 compound thin films was a direct allowed transition and decrease of values (2.8-1.8eV), if the laser energy is increased, also the increasing of thickness from (130.26 - 176.83 ±7) nm of the film as a result to the increase laser energy. The optical constants such as refractive index, extinction coefficient and dielectric constant have been calculated for the prepared films.