Light energy conversion system using Bi-based perovskite hybrid compounds

有机-无机卤化铅钙钛矿的低稳定性和铅的毒性一直是人们关注的问题。另一方面，无毒、高稳定的铋基低维钙钛矿和碘化铋（BiI3）半导体材料的性能由于固有载流子浓度高、激子结合能高和形貌差而受到限制。为了解决这个问题，我们调制了一种溶剂介导的加合物，在较低温度（90°C）下一步结晶无铅AgBi2I7，并通过控制底物和前驱体浓度的性质获得了残留的BiI3。这最终导致了电能转换效率的显著提高，达到2.12%，以及AgBi2I7太阳能电池对光、热、湿的长期稳定性。

Low stability of organic-inorganic lead halide perovskite and toxicity of lead (Pb) still remains a concern. On the other hand, the performance of non-toxic, high stable bismuth based lower dimensional perovskite and bismuth iodide (BiI3) semiconducting material has been limited due to high intrinsic carrier concentration, high exciton binding energy and poor morphology. To address this, we modulated a solvent-mediated adduct for one-step crystallization of lead-free AgBi2I7 at a lower temperature (90 °C) and to obtain remnant BiI3 by controlling the nature of the substrate and precursor concentration. This eventually resulted in remarkable enhancement in the power conversion efficiency, reaching 2.12%, and the long-term stability of AgBi2I7 solar cells towards light, heat and humidity.