Zero-dimensional methylammonium iodo bismuthate solar cells and synergistic interactions with silicon nanocrystals

Organometal trihalide perovskite solar cells have attracted monumental attention in recent years. Today's best devices, based on a three-dimensional perovskite structure of corner-sharing PbI₆ octahedra, are unstable, toxic, and display hysteresis in current-voltage measurements. We present zero-dimensional organic-inorganic hybrid solar cells based on methylammonium iodo bismuthate (CH₃NH₃)₃(Bi₂I₉) (MABI) comprising a Bi₂I₉ bioctahedra and observe very low hysteresis for scan rates in the broad range of 150 mV s^-1 to 1500 mV s^-1 without any interfacial layer engineering. We confirm good stability for devices produced and stored in open air without humidity control. The MABI structure can also accommodate silicon nanocrystals, leading to an enhancement in the short-circuit current. Through the material MABI, we demonstrate a promising alternative to the organometal trihalide perovskite class and present a model material for future composite third-generation photovoltaics.