Electrical and optical properties of tin selenide nanostructured thin films and their electronic junction

Abstract

SnSe nanocrystals play a significant role in photovoltaic applications. SnSe nanomaterial powder has been prepared by solvothermal technique. SnSe nanocrystalline thin films of different thicknesses have been successfully prepared by thermal evaporation technique on glass, quartz and silicon substrate. The structural, electrical and optical properties have been investigated for SnSe thin films as a function of thickness and annealing temperature. The electrical and photoelectrical properties of Ag/p-SnSe/p-Si/Al heterojunction have been investigated. Structural characterization of prepared SnSe nanomaterial showed that the nanomaterial has nearly stoichiometric composition with orthorhombic structure. The as-deposited SnSe films of different thicknesses (46, 58, 80 and 100 nm) have orthorhombic structure with crystallite size increases as the film thickness increase. The annealing of SnSe films of thickness 58 nm at 150 ºC resulted in increase in the degree of crystallinity of the films, whereas the annealing at 300 ºC lead to partially transformation of the SnSe film to SnSe2 with hexagonal structure. From electrical measurements, the films showed semiconducting behavior. The variations of resistivity, carriers concentration and carriers mobility as a function of temperature were investigated for different film thickness and annealing temperature