Composition engineering of antimony selenosulfide films using hydrothermal method for efficient solar cells

In this work, Sb2SeyS3-y films were prepared by hydrothermal method at 135 °C for 135 min. The influence of the growth solution volume, the mixing S source, the selenourea concentration and the etching by the N-butyldithiocarbamic acid (BDCA) solution in DMF on the thickness, the content of Sb–O, Se, S and the Se distribution in Sb2SeyS3-y films and the power conversion efficiency (PCE) of solar cells was systematically investigated. When the growth solution volume was 30 mL and the chemical composition of the growth solution was 25 mM antimony potassium tartrate (KSbC4H4O7·0.5H2O), 75 mM Na2S2O3, 5 mM thioacetamide, 10.5 mM selenourea, the PCE of Sb2SeyS3-y solar cells were 9.56 % and 9.41 ± 0.10 %. When Sb2SeyS3-y films were etching by BDCA for 10 min, the PCE of Sb2SeyS3-y solar cells were 10.13 % and 9.95 ± 0.16 %. The result revealed that the homogeneous extent of the Se distribution in Sb2SeyS3-y films can be improved by changing the hydrothermal process parameters and the chemical composition of the growth solution. And the etching by BDCA should be an efficient strategy for eliminating the surface defects and decreasing the gradient of the Se distribution in Sb2SeyS3-y films.