Thermal Management Enables Bright and Stable Perovskite Light‐Emitting Diodes

The performance of lead-halide perovskite light-emitting diodes (LEDs) has increased rapidly in recent years. However, most reports feature devices operated at relatively small current densities (-2 ) with moderate radiance (-1 m-2 ). Here, Joule heating and inefficient thermal dissipation are shown to be major obstacles toward high radiance and long lifetime. Several thermal management strategies are proposed in this work, such as doping charge-transport layers, optimizing device geometry, and attaching heat spreaders and sinks. Combining these strategies, high-performance perovskite LEDs are demonstrated with maximum radiance of 2555 W sr-1 m-2 , peak external quantum efficiency (EQE) of 17%, considerably reduced EQE roll-off (EQE > 10% to current densities as high as 2000 mA cm-2 ), and tenfold increase in operational lifetime (when driven at 100 mA cm-2 ). Furthermore, with proper thermal management, a maximum current density of 2.5 kA cm-2 and an EQE of ≈1% at 1 kA cm-2 are shown using electrical pulses, which represents an important milestone toward electrically driven perovskite lasers.