The Effect of substrate temperature and the annealing time on the optical properties of the AgInS2 thin films prepared by chemical spray pyrolysis Technique

The agins2 thin films were prepared on a glass substrates with different substrate temperatures (623, 573, 523 and 473) k by chemical spray pyrolysis . for annealing temperature 473 k , different time ( 2, 2.5 and 3) hours have been applied .the structure test produced by used the x-ray techniques by (diffraction and diffractometer philips 200) system with copper target (cu - kα), wavelength (0.15406 nm), the average is (2000counts/sec), the voltage is (40 kv) , the scanning average is (5 deg /min) and the angle range is (2θ =20o – 60o).the optical properties of theagins2 films were determined from the absorbance (a) and the transmittance (t) data , using uv-vis. spectrophotometer at wavelength (400 – 1000) nm at room temperature.the direct band gap of (1.87 – 2.46) ev has been found that of the agins2 thin films according the substrate temperature , also , it is affected by annealing time and becomes ( 1.82 – 2.15) ev . the optical constants (α , k , n ) are also changed as the substrate temperature and annealing time change .the agins2 films regard as active selecting films in the range (400 – 665) nm , and can be used as an absorber layers in solar cells and optoelectric devices.