Recent progress toward perovskite light-emitting diodes with enhanced spectral and operational stability

Perovskite light-emitting diodes (PeLEDs) have gained tremendous attention in the past several years because of their high efficiency, low fabrication cost, highly pure and widely tunable light emission, and so on. With great efforts on the engineering of perovskite compositions and device structures, the external quantum efficiency of PeLEDs has been dramatically boosted to more than 20%, well comparable with the current commercialized light-emitting technologies. However, the poor operational stability, including the spectral instability in pure-blue (emission wavelength, 450-470 nm) and pure-red (emission wavelength, 620-650 nm) PeLEDs and short operational lifetime under electrical bias, still hinders their possible practical applications. In this review, we summarize the recent progress on the development of perovskite materials and device structures to improve spectral stability in pure-blue and pure-red PeLEDs and device operational stability under working conditions. In addition, we also present an outlook on possible strategies that can be used to further improve the stability of PeLEDs. (C) 2019 Elsevier Ltd. All rights reserved.