Unprecedentedly high indoor performance (efficiency > 34 %) of perovskite photovoltaics with controlled bromine doping

Indoor lighting-driven photovoltaic cells have significant potential for energy generation due to their ability to convert waste lighting into reusable sources and energy generation regardless of weather conditions. As a promising renewable source of energy, indoor perovskite photovoltaic cells possess the advantages of high efficiency, facile processability, and cost-effectiveness. Here, we propose stoichiometry-controlled perovskite-based photovoltaic cells illuminated under the dim light-emitting diode (LED) to capture and recycle the light sources. Among the various stoichiometric methods tested, 10% bromide-doped perovskite photoactive layers exhibit the best performance as a result of better crystallization and uniform surface. This helps to form larger grains of perovskite with reduced trap sites and defects, which suppresses carrier trapping and non-radiation recombination centers, resulting in improved device performance. Moreover, additional substitution by an appropriate halide increases the stability of the conventional perovskite by forming a pseudo-cubic phase. Consequently, the photovoltaic device examined under dim LED (1000 lx) indoor lighting exhibits an average power conversion efficiency of 34.5 ± 1.2%, which is superior by 18% compared with that of a control device (29.2 ± 1.6%). These results reveal the potential of indoor-driven perovskite photovoltaic cells as next-generation power sources which may pioneer the development of new types of indoor electronics.