Investigation of Annealing Effects and Film Thickness Dependence on the Optical Properties of Vacuum Evaporated Cu_2SnSe_3 Chalcogenide Thin Films

摘要

In recent years, much attention has been paid to semiconducting I_2-IV-VI_3 compounds because of their optoelectronic properties and application. Among the I_2-IV-VI_3 semiconducting semiconductors, Copper Tin Selenide, Cu_2SnSe_3, are of great interest because they are potential candidates in many practical application such as solar cell applications. In this study, surface profilometer and ultraviolet-visible (UV-VIS) spectrophotometer were used to investigate the films thickness dependence and annealing effect on the optical properties of Cu_2SnSe_3 thin films prepared by thermal evaporation method that coated on well-cleaned glass substrates. The Cu_2SnSe_3 were annealed at 100℃, 200℃, 300℃, 400℃ and 500℃ under flowing nitrogen, N_2, atmosphere. The variations of optical parameters, such as absorbance, reflectance, direct band gap, indirect band gap as well as Urbach energy gap are studied.