Influence of Al dopant on structural and optical parameters of AgInSe2 thin film

Chalcopyrite thin films ternary Silver Indium Diselenide AgInSe2 (AIS) pure and Aluminum Al doped with ratio 0.03 was prepared using thermal evaporation with a vacuum of 7*10-6 torr on glass with (400) nm thickness for study the structural and optical properties. X-ray diffraction was used to show the inflance of Al ratio dopant on structural properties. X-ray diffraction show that thin films AIS pure, Al doped at RT and annealing at 573 K are polycrystalline with tetragonal structure with preferential orientation (112). raise the crystallinity degree. AFM used to study the effect of Al on surfaces roughness and Grain Size Optical properties such as the optical band gap, absorption coefficient, Extinction coefficient, refractive index, real and imaginary part of dielectric constant were calculated to inspect the influence of the Aluminum on the optical Parameters of AIS thin film. UV/Visible measure show the lowering in energy gap to 1.35 eV for AgInSe2: Al at 573 K this energy gap making these samples suitable for photovoltaic application.