Recent progress in perovskite light-emitting diodes with high external quantum efficiency and stability

Due to their tunable emission wavelength, high color purity, and high external quantum efficiency (EQE), perovskite light-emitting diodes (PeLEDs) have emerged as the most promising candidates for next-generation flat lighting applications and high-definition flexible displays. In recent years, the EQE and stability of PeLEDs have significantly improved, with the EQE of red (including near-infrared), green and blue PeLEDs exceeding 25% and the lifetime of PeLEDs reaching 12 500 hours. The improvements in the EQE and stability of high-performance PeLEDs involve numerous targeted performance improvement strategies. Thus, analyzing and summarizing these improvement strategies have practical significance in this field. This review first elaborates on the research progress of several representative PeLEDs, mainly focusing on their two core performance parameters, i.e., EQE and stability, and subsequently categorizes and summarizes their performance improvement strategies. Based on the performances of some highly efficient PeLEDs, we emphasize the possible directions for future research on PeLEDs with ultra-high efficiency and stability.