Effective Dopants Pb and Pb‐SiW12 to Enhance Sb2S3‐Based Photodetector Performance

Abstract

AbstractSb2S3 has excellent photovoltaic properties, but the performance of its photovoltaic devices still needs to be improved. The main issues hindering its photovoltaic performance are the poor carrier transport ability and the significant charge recombination. Doping strategies play a key role in addressing these issues. This study investigates the effect of Pb(CH3COO)2 (Pb) and [Pb(DMF)7]2[SiW12O40] 2DMF (Pb‐SiW12) doping on the photovoltaic properties of Sb2S3 thin films. It is found that the intensity of diffraction peaks on the (130) crystal plane of Pb‐doped Sb2S3 and the (221) crystal plane of Pb‐SiW12@Sb2S3 is increased, which enhances the crystallinity of the films. Meanwhile, Pb and Pb‐SiW12 doping narrow the bandgap (1.69 eV) of Sb2S3 to 1.65 eV and 1.62 eV. Electrochemical tests show that the carrier concentration and carrier lifetime are increased. The Pb‐doped Sb2S3 photodetector photocurrent of 14 μA, 7 times higher than the 2 μA pristine Sb2S3 photodetector. It exhibits a responsivity of 13.9 mA/W and detectivity of 1.2×1011 Jones. The Pb‐SiW12@Sb2S3 photodetector photocurrent is 11 μA. Pb‐SiW12 can immobilize Pb while reducing the amount of Pb. The methodology in this work provides a way to improve the performance of Sb2S3 thin‐film photodetectors.