One–step synthesis of Cu3BiS3 thin films by a dimethyl sulfoxide (DMSO)–based solution coating process for solar cell application

A large–grain and highly crystalline Cu 3 BiS 3 thin film is successfully prepared by a dimethyl sulfoxide (DMSO)–based solution coating process . Without involving post sulfurization , Cu 3 BiS 3 absorber with grain size of ~ 1   µm has been achieved via a short-time drying of spin–coated precursor film on a hot plate at relatively low temperatures (< 300   °C). Our Cu 3 BiS 3 film exhibits a direct band gap of 1.47   eV with high absorption coefficients (~ 7 × 10 4   cm −1 ). Hall effect measurements reveal a p–type conductivity with hole concentration of ~ 10 16   cm −3 and mobility of 52.83   cm 2 /(V   s). Moreover, an initial Cu 3 BiS 3 thin film solar cell with the device structure of glass/Mo/Cu 3 BiS 3 /CdS/ZnO/ITO/Al is fabricated, achieving a definite conversion efficiency of 0.17%. The mild preparation condition promises great potential of current method in realizing Cu 3 BiS 3 solar cells on temperature-sensitive substrates such as flexible polymer through an energy efficient way. The Cu 3 BiS 3 has thus been presented as a promising absorber material for solar cell applications.