Moisture-induced ionovoltaic electricity generation using lead free 2-dimensional Cs3SbBiBr9 perovskite†

Abstract

In the field of solar energy applications, ion migration is a significant challenge. A promising solution to tackle this issue is through the Ionovoltaic Electricity Generator (IEG) effect observed in two-dimensional (2D) lead-free halide perovskite structures equipped with lateral electrodes. These devices with millimeter-spaced lateral electrodes generate electricity through moisture absorption. As moisture is absorbed, it creates an uneven distribution of ions, establishing a gradient that prompts ion migration. This migration generates a voltage difference across the electrodes, which in turn propels electrons through an external circuit, producing electrical power. Furthermore, humidity plays a crucial role in enhancing power generation by aiding in ion formation. In this study, we successfully synthesized mixed alloys of antimony and bismuth in the form of nanosheets of Cs₃SbBiBr₉ using a solution-based approach. The Cs₃SbBiBr₉ device, covering an area of 0.3 cm² (1.5 cm × 0.2 cm), demonstrated an open-circuit voltage (V_oc) of 0.22 V and a short-circuit current (I_sc) of 35 μA at 85% relative humidity (RH).