Effect of substrate temperature on the growth of CuSbS2 thin films by chemical spray pyrolysis

CuSbS 2 is an emerging potential compound semiconductor for absorber layer in thin film heterojunction solar cell. Spray pyrolysis technique has been successfully employed to deposit CuSbS 2 thin films onto soda-lime glass substrates held at different substrate temperatures in the range of 220 °C–280 °C. The structural and optical analysis revealed that films deposited at 260 °C are CuSbS 2 with chalcostibite structure. The films deposited at other substrate temperatures contained binary/ternary phases like Cu 2-x S, Cu 3 SbS 4 and Cu 12 Sb 4 S 13 . The lattice parameters of CuSbS 2 films are found to be a = 0.599 nm, b = 0.379 nm and c = 1.449 nm respectively. The band gap of CuSbS 2 films is close to the optimum band gap (1.5eV) required for highest theoretical photovoltaic conversion efficiency. The optical absorption coefficient value lies in the range of 10 4 cm −1 . The nature of these films is found to be p-type. • CuSbS 2 thin films are an alternative emerging potential solar cell absorber layer to traditional solar cell absorber layers like Cu(In,Ga)(S,Se) 2 , CdTe and Cu 2 ZnSn(S,Se) 4 . • CuSbS 2 thin films were deposited by a low-cost technique. • Obtaining phase-pure CuSbS 2 thin films is challenging task. • The optimum substrate temperature of CuSbS 2 thin films was found.