Antimony selenide thin films prepared by thermal evaporation of antimony and selenium elemental sources

Abstract

Antimony selenide thin films of 140–190 nm in thickness, with different compositions, were prepared at room temperature by using the dual-thermal evaporation technique. The compositional, structural, morphological and optical studies were performed in the as-deposited state and after annealing at 250°C for an hour, using many analytical techniques. The carrier-type, resistivity, carrier concentration and mobility of the annealed films were determined. The obtained thin films, regardless of their composition, exhibited a smooth surface with a high absorption coefficient of greater than 105 cm−1. The optical band gap of the near-stoichiometric film was 1.56 eV, which decreased to 1.32 eV after annealing. However, higher values were determined with increasing Se elements in the films, but these values did not exceed 1.77 eV. This study shows that antimony selenide thin films can be obtained at room temperature using a thermal evaporation technique, and the properties of the films can be improved with annealing.

Keywords

• Dual-thermal evaporation
• thin films
• Sb–Se
• annealing temperature