Reciprocally Photovoltaic Light‐Emitting Diode Based on Dispersive Perovskite Nanocrystal

Abstract Integrating highly efficient photovoltaic (PV) function into light‐emitting diodes (LEDs) for multifunctional display is of great significance for compact low‐power electronics, but it remains challenging. Herein, it is demonstrated that solution engineered perovskite nanocrystals (PNCs, ≈100 nm) enable efficient electroluminescence (EL) and PV performance within a single device through tailoring the dispersity and interface. It delivers the maximum brightness of 490 W sr⁻¹ m⁻² at 2.7 V and 23.2% EL external quantum efficiency, a record value for near‐infrared perovskite LED, as well as 15.23% PV efficiency, among the highest value for nanocrystal perovskite solar cells. The PV–EL performance is well in line with the reciprocity relation. These all‐solution‐processed PV‐LED devices open up viable routes to a variety of advanced applications, from touchless interactive screens to energy harvesting displays and data communication.