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.