Tailoring Triple-Anion Perovskite Material for Indoor Light Harvesting with Restrained Halide Segregation and Record High Efficiency Beyond 36%

Indoor photovoltaics are promising to enable self-powered electronic devices for the Internet of Things. Here, reported is a triple-anion CH3NH3PbI2-xBrClx perovskite film, of which the bandgap is specially designed for indoor light harvesting to achieve a record high efficiency of 36.2% with distinctive high open circuit voltage (V-oc) of 1.028 V under standard 1000 lux fluorescent light. The involvement of both bromide and chloride suppresses the trap-states and nonradiative recombination loss, exhibiting a remarkable ideality factor of 1.097. The introduction of chloride successfully restrains the halide segregation of iodide and bromide, stabilizing the triple-anion perovskite film. The devices show an excellent long-term performance, sustaining over 95% of original efficiency under continuous light soaking over 2000 h. These findings show the importance and potential of I/Br/Cl triple-anion perovskite with tailored bandgap and suppressed trap-states in stable and efficient indoor light recycling.