Thermally induced changes in optical and electrical properties of SnSb2S4 thin films

Sulfosalt SnSb 2 S 4 films for optical and electrical applications have been prepared on glass substrates by thermal evaporation and subsequently thermally annealed in vacuum at temperatures from 100 to 200 °C. The optical and structural properties of the films were studied as a function of the annealing temperature. The SnSb 2 S 4 films exhibit a polycrystalline structure and undergo abrupt changes in electrical and optical properties at a transition temperature of 140 °C. After annealing below the transition temperature, the films are highly resistive with a dominant amorphous component, but when annealed above this temperature, the samples exhibit p + -type semiconductor behaviour with a dominant crystalline component