摘要
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•First investigation for the panchromatic absorption from Sb based perovskites by using complimentary absorbing ETLs.•Adduct formation for ITIC molecule with Cs3Sb2I9 have also been investigated.•Optical simulations were conducted to calculate the contribution to current density from each layer.•Best solar cell efficiency of 3.2% for inorganic Sb based perovskite was achieved.•A3B2X9 perovskite is studied under indoor light illumination and an efficiency of 9.2% was achieved under 1000 Lux.
The search for stable alternative lead-free perovskites has identified all-inorganic antimony/bismuth halide derivatives as promising materials. Despite attractive optoelectronic properties, their wider band gaps and poor morphological control have greatly limited their solar device performance. In this study, we used the indacenodithiophene-based organic acceptor (ITIC) as a Lewis base to improve the morphology of Cs3Sb2I9 films and also as an electron transport layer to form a complimentary heterojunction, and, thereby, enhance the performance of Cs3Sb2I9 solar cells. The presence of cyano and carbonyl groups in ITIC modulated the rate of crystallization of Cs3Sb2I9 and improved its optoelectronic properties. The panchromatic absorption of the Cs3Sb2I9/ITIC heterostructure provided a power conversion efficiency of 3.25% in inverted solar cell structure under 1-sun irradiation. This enhanced performance when using a complimentary absorption strategy suggests a new pathway for developing wider-band-gap lead-free perovskite derivatives for solar cell applications. Moreover, the optimized Cs3Sb2I9/ITIC heterostructure–based solar cell achieved a PCE of 9.2% under indoor illumination at 1000 lx, highlighting the potential use of such devices in indoor applications.