Structural and optical properties of amorphous Sb2S3 thin films deposited by vacuum thermal evaporation method

Sb2S3 thin films have been deposited by vacuum thermal evaporation onto glass substrates at various substrate temperatures in the range of 30–240 °C. Crushed powder of the synthesized Sb2S3 was used as raw material for the vacuum thermal evaporation. The structural investigation performed by means of X-ray diffraction (XRD) showed that the all as-deposited films present an amorphous structure and all the films were highly resistive. The reflectance and transmittance of the films are measured in the incident wavelength range 300–1800 nm. The absorption coefficient spectral analysis revealed the existence of long and wide band tails of the localized states in the low absorption region. The band tails width is calculated and found to be varying between 0.024 and 0.032 eV. The analysis of the absorption coefficient in the high absorption region revealed two direct forbidden band gaps between 1.78–1.98 eV and 1.86–2.08 eV.

► Sb2S3 thin films were deposited at glass substrates using the thermal vacuum evaporation technique.
► The X-ray analysis indicates that all the as-deposited films are amorphous in nature.
► Relatively high absorption coefficients between 104 cm−1 and 105 cm−1 were calculated.
► The long band tails of width between 0.028 and 0.032 eV at low absorption coefficient values.
► We report an absorber material in solar cells applications.