Nano-crystalline tin selenide thin films: synthesis and characterization

A simple, straightforward, and facile drop-casting technique was used to prepare thin films of tin selenide (SnSe) at 220 degrees C substrate temperature using triethanolamine as complexing agent. SnCl2 and Na2SeSO3 precursors were used as source materials for the thin film synthesis. The drop-casted film was annealed at 400 degrees C. Surface morphological, structural, electrical, and optical properties of the synthesized films were analyzed by scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), X-ray powder diffraction (XRD), high-precision digital multimeter, and UV-visible spectroscopy, respectively. The XRD study of synthesized film showed the presence of nanocrystallinity with orthorhombic crystal structure of SnSe. SEM images indicated that small grains agglomerated to form a bunch of bigger size. SEM data showed good continuity of SnSe film. Hot probe method was used to confirm the carrier type of film. SnSe thin films were p-type having 1.4 eV bandgap, and their electrical conductivity was in the order of 10 S cm(-1) which made them suitable to use it in the solar cell as an absorber layer. (C) 2021 Elsevier Ltd. All rights reserved.