Abstract
Thin Bi2Se3 layers are promising material for many optical and optoelectronic applications. In this work, thin crystalline layers of Bi2-chalcogenides were deposited on highly cleaned glass substrates by vacuum thermal evaporation technique. The optical properties of the concerned layers were investigated with ultraviolet–visible-near infra-red (UV–Vis–NIR) spectra. The effect of thickness reduction and the annealing treatment have been studied. Thinning the film to few nanometers resulted in a significant enhancement of light transmission through the prepared materials. Also, simultaneous reduction of layer's thickness and annealing treatment significantly improved the optical transmission. Such transmissivity enhancement opens avenues for transparent electrode applications.
•Bi2Se3 and based layers were prepared with different layer's thicknesses.•Direct allowed band transition is revealed in all films.•The annealing profoundly affected the optical band gap.•Substantial enhancement in the optical transmission was achieved.