Versatile interfacial modifier enabling efficient antimony selenosulfide indoor photovoltaics

Abstract Antimony selenosulfide (Sb 2 (S,Se) 3 ) is a promising photovoltaic absorber material for both outdoor and indoor application scenarios. Nevertheless, the performance of Sb 2 (S,Se) 3 solar cells remains constrained by the severe interface trap-induced nonradiative recombination. Interface engineering has been recognized as an effective approach to suppress recombination and boost charge transport. In this work, we introduce an organic modifier (O-BDT) between Sb 2 (S,Se) 3 absorber and hole transport layer. The theoretical and experimental results evidence that O-BDT can simultaneously passivates interface defects and optimizes the energy-level alignment, leading to a significantly reduced voltage loss. Finally, the O-BDT modified solar cell achieves a power conversion efficiency (PCE) of 8.01% under AM 1.5G illumination. Moreover, the device delivers a PCE of 19.04% under 1000 lux, 3312 K LED lighting, among the best list of IPVs based on antimony chalcogenide compounds.