A study on influence of potential defects and optimization of device structure for CuSbS2 based thin film solar cell using SCAPS – 1D simulator

Copper antimony sulphide (CuSbS2) is a benign material for next generation thin film solar cell technology due to its non-toxicity, low cost, and earth abundant ingredients. The noteworthy features of CuSbS2 are its high absorption coefficient and suitable bandgap. In this work, we computationally analyzed the CuSbS2 thin film solar cell using SCAPS-1D simulation software in order to boost the performance of CuSbS2 solar cell by exploring the individual and integrated effects of stoichiometric defects and interface defects, CuSbS2 layer thickness, auger hole capture coefficient, CdS layer thickness, back contact materials and parasitic resistances. The study reveals that stoichiometric (CuSb and VS) and interface defects affect perniciously on the solar cell parameters. The optimum thickness of CuSbS2 and CdS layer is 500 nm and 60 nm, respectively. In addition to the investigations with CdS as a buffer layer, we also carried out a comparative study on performance of CuSbS2 based thin film solar cell by changing the buffer layer material to Zn(O,S) and found that the device with CdS as a buffer layer gives marginally better efficiency and particularly higher short-circuit current as compared to that with Zn(O,S) as a buffer layer.