Synthesis of Sb(V) Complexes with Pyridyl Cations and Application for Lead-free Perovskite Solar Cells

Lead halide perovskite has emerged as a promising photovoltaic material due to its excellent power conversion efficiency (PCE). However, the toxicity problem of lead-based perovskite hampers the commercialization of perovskite solar cells. Here, we develop several Sb(V) complexes with pyridyl cations and serve as absorber layer for lead-free perovskite solar cells. The designed complexes were based on 4-tert-butylpyridine (tBP) and N-ethylpyridinium (N-EtPy) cations with bandgaps of 2.01 eV and 1.95 eV, which showed their potential for solar cells and optoelectronic applications. We also found a chemical rule for stable Sb complexes in terms of the bond connectivity of pnictogen-antimony. Initial studies produce a solar cell with a PCE of 0.9% and offer inspiration for further exploration of environment-friendly perovskite families.