OPTICAL-CONSTANTS OF AMORPHOUS GA2SE3

The optical response in amorphous (a-)Ga2Se3 Semiconductor in the 1.2-5.6-eV photon-energy range at room temperature has been measured by spectroscopic ellipsometry. It is found that the dielectric function epsilon=epsilon1+iepsilon2 of a-Ga2Se3 strongly resembles those of amorphous tetrahedrally bonded semiconductors. The optical energy gap estimated from the plots of Eepsilon2(E)1/2 versus E (photon energy) is 1.75 eV. Dielectric-related optical constants, such as the complex refractive index and absorption coefficient, of this amorphous semiconductor have also been presented.