Perovskite/Organic Hybrid White Electroluminescent Devices with Stable Spectrum and Extended Operating Lifetime

Abstract

We demonstrate a kind of perovskite/organic hybrid white electroluminescent device, where an ultrathin doping-free organic phosphorescent interlayer is embedded between a p-type hole transport layer and a ntype electron transport layer to give an organic p−i−n heterojunction unit, which is superimposed layer by layer onto a quasi-two-dimensional perovskite layer. The unique carrier transport character of the p-type hole transport layer leads to a broad carrier recombination region approaching the p−i−n heterojunction unit. As a result, pure-red emission from the perovskite layer and sky-blue emission from the organic p−i−n heterojunction were simultaneously achieved to generate white emission with a peak external quantum efficiency of 7.35%, Commission Internationale de L'Eclairage coordinates of (0.424, 0.363), and a low correlated color temperature of 2868 K. More importantly, excellent spectral stability and a greatly enhanced operating lifetime (10-fold longer than those of perovskite-only LEDs) are simultaneously achieved, providing a new path for the development of high-performance white LEDs.

Energy Regulation in White-Light-Emitting Diodes

“…Hence, for improving mixed SEL-WPeLEDs or stacked-WPeLEDs, perovskites were often mixed with organic molecules to form hybrid WLEDs, 17 where energy-transfer regulation was similar to that previously mentioned. For example, Liu et al 88 reported a perovskite/organic hybrid WLED with a peak EQE of 7.35%. An ultrathin phosphorescent interlayer was inserted between a ptype hole transport layer and an n-type electron transport layer, forming an organic p-i-n heterojunction unit.…”

Metal halide perovskites-based white light-emitting diodes

“…With this tandem structure of LEDs, the typical white light emission with steady CIE coordinates of (0.32, 0.32) and a CCT of ∼6000 K was achieved in a wide range of driving current densities (figures 4(d)-(f)). It is worth mentioning that the WLEDs based on red perovskite and sky-blue organic p-i-n heterojunction have realized by Su et al in 2022 [82]. They sequentially stacked organic p-i-n heterojunctions on perovskite layers by vacuum deposition.…”

Advances in electrically driven light-emitting diodes based on lead-free metal halides

“…1,2 Light-emitting materials play a critical role in achieving highly efficient OLEDs. [3][4][5][6] Green and red phosphors based on iridium(III) complexes have been employed in commercialized OLEDs due to their excellent stability, tunable emission and superior device efficiency. 7 However, the low abundance of iridium on the earth is not conducive to its sustainable development.…”