The Effect of annealing temperature on the optical properties of (Cu2S)100-x( SnS2 )x thin films

Thin films of (Cu2S)100-x( SnS2 )x at X=[ 30,40, 50)]% with thickness (0.9±0.03)μm , had been prepared by chemical spray pyrolysis method on glass substrates at 373K. These films were then annealed under low pressure of(10-2) mbar )373,423 473)K for one hour . This research includes , studying the the optical properties of (Cu2S)100-x-(SnS2)x at X=[ 30,40, 50)]% .Moreover studying the effect of annealing on their optical properties , in order to fabricate films with high stability and transmittance that can be used in solar cells. The transmittance and absorbance spectra had been recorded in the wavelength range (310 - 1100) nm in order to study the optical properties . It was found that these films had direct optical band gap which decreases with the increasing SnS2 ratio , while it increasing with the increase in the annealing temperature at all ratio