Fabrication of CuSbS2 Thin Film Solar Cells by Using Chemical Spray Pyrolysis

CuSbS₂ is a promising compound semiconductor for the thin film heterojunction solar cell absorber layer. The chemical spray pyrolysis technique is adopted to fabricate CuSbS₂ thin film solar cells. The aqueous solution is sprayed over the soda-lime glass substrates at a constant spray rate of 10 ml/min. The films are obtained at the optimum substrate temperature of 260 °C. The thin films' of XRD spectra reveal the polycrystalline nature of the chalcostibite structure of CuSbS₂, with lattice parameters of a = 0.600 nm, b = 0.380 nm, and c = 1.445 nm respectively. Micro-Raman spectra also confirm the CuSbS₂ crystal phase. The optical band gap of these films is found to be 1.44 eV, which is close to the optimum band gap for maximal conversion efficiency. The optical absorption coefficient of these films is ≥ 10⁴ cm^-1. These films are found to be p-type. Finally, work on fabricating a conventional thin film heterojunction solar cell is undertaken. CuSbS₂ thin film solar cell is prepared in substrate configuration in the sequence of Mo-glass/CuSbS₂/CdS/Au. The fabricated solar cell exhibited an open circuit voltage and short circuit current of 141 mV and 1.62 mA/cm² respectively.