Effect of Ge Addition on the Optical Band Gap and Refractive Index of Thermally Evaporated As2Se3 Thin Films

Abstract EN

The present paper reports the effect of Ge addition on the optical band gap and refractive index of As2Se3 thin films.

Thin films of As2Se3 and (As2Se3)90Ge10 were prepared by thermal evaporation technique at base pressure 10−4 Pa.

Optical band gap and refractive index were calculated by analyzing the transmission spectrum in the spectral range 400–1500 nm.

The optical band gap decreases while the refractive index increases with the addition of Ge to As2Se3.

The decrease of optical band gap has been explained on the basis of density of states; and the increase in refractive index has been explained on the basis increase in disorder in the system.