Enhanced hydrothermal heterogeneous deposition with surfactant additives for efficient Sb2S3 solar cells

Antimony sulfide (Sb 2 S 3 ) has great potential as a promising wide–bandgap, low–cost, low–toxicity, and stable photovoltaic material for next–generation indoor and tandem photovoltaic applications. This article reports that there are competitive chemical reaction mechanisms during hydrothermal preparation of Sb 2 S 3 , and we present an effective strategy to control these mechanisms using the anionic surfactant sodium dodecyl sulfate (SDS) as a reaction additive. We found that the SDS additive significantly enhances the hydrothermal heterogeneous reaction path and thus improves the quality of the Sb 2 S 3 absorber by shifting the balance between homogeneous and heterogeneous reactions. An efficiency of 6.84% under standard AM1.5 illumination irradiance is achieved. The SDS–optimized Sb 2 S 3 solar cells also show remarkably high indoor photovoltaic performance. An efficiency as high as 16.37% is reported under indoor illumination by a 1000 lx white light LED source. This result indicates the excellent prospects of Sb 2 S 3 in a broad range of photovoltaic applications.