Study of Some Structural and Optical Properties of AgAlSe2 Thin Films

Abstract

The structural properties of ternary chalcopyrite AgAlSe2 compound alloys and thinfilms that prepared by the thermal evaporation method at room temperature on glass substratewith a deposition rate (5±0.1) nm s-1 for different values of thickness (250,500 and 750±20)nm, have been studied, using X-ray diffraction technology. As well as, the optical propertiesof the prepared films have been investigated. The structural investigated shows that the alloyhas polycrystalline structure of tetragonal type with preferential orientation (112), while thefilms have amorphous structure. Optical measurement shows that AgAlSe2 films have highabsorption in the range of wavelength (350-700 nm). The optical energy gap for alloweddirect transition were evaluated, which decreases with film thickness increasing, i.e. itdecreases from 2.5 eV to 2.2 eV when thickness varies from 250±20 nm to 750±20 nm.