Abstract
•Successful growth of Cu3BiS3 thin films using thermal evaporation.•Growth temperature enhances the photoelectric properties of Cu3BiS3 thin films.•Cu3BiS3 solar cell absorber was successfully implemented in solar cell device.
Ternary copper sulphides, especially copper-bismuth-sulphide (Cu-Bi-S), are alternative solar absorber materials due to their earth-abundant and non-toxic constituent elements, compared to the conventional copper indium gallium sulphide and cadmium telluride films. In this study, Cu-Bi-S thin films were deposited onto soda lime glass substrates using a one stage co-evaporation process from Cu2S and Bi2S3 sources, with the deposition temperatures varied from room temperature to 400 °C. X-ray diffraction analysis confirmed that Cu3BiS3 was the dominant phase in the Cu-rich films, and the crystalline quality of the films was significantly improved with increasing the deposition temperature. An optical bandgap of 1.4 eV was achieved for the film deposited at 400 °C, which demonstrated a Hall mobility of 3.95 cm2/V-s and a carrier concentration of 7.48 × 1016 cm−3. Cu3BiS3 films deposited at 375 and 400 °C were implemented into superstrate solar cell structures (glass/ITO/n-CdS/p-Cu3BiS3/Al).