High-efficiency hybrid organic–inorganic light-emitting devices

•Enhanced electron injection from ZnO into light emitting polymers by PEIE.•Efficient RGB hybrid organic–inorganic light emitting devices.•Electrophosphorescent devices using solution-processed small molecule emissive layer.

We report efficient red, orange, green and blue organic–inorganic light emitting devices using light emitting polymers and polyethylenimine ethoxylated (PEIE) interlayer with the respective luminance efficiency of 1.3, 2.7, 10 and 4.1 cd A−1, which is comparable to that of the analogous conventional devices using a low work-function metal cathode. This is enabled by the enhanced electron injection due to the effective reduction of the ZnO work-function by PEIE, as well as hole/exciton-blocking function of PEIE layer. Due to the benign compatibility between PEIE and the neighboring organic layer, the novel phosphorescent organic–inorganic devices using solution-processed small molecule emissive layer show the maximum luminance efficiency of 87.6 cd A−1 and external quantum efficiency of 20.9% at 1000 cd m−2.

Graphical abstractPhosphorescent hybrid organic–inorganic light emitting devices using solution-processed small molecule emissive layer show the maximum luminance efficiency of 87.6 cd A−1, which is among the best reported luminance efficiency values for solution-processed light emitting devices.Figure optionsDownload full-size imageDownload as PowerPoint slide