An efficient all-inorganic cesium halide perovskite light-emitting diode (PeLED) was demonstrated by utilizing a mixed perovskite film of CsPbBr₃:4,5-di (9H-carbazol-9-yl) phthalonitrile (2CzPN) as the light-emitting layer, where 2CzPN was a thermally activated delayed fluorescence (TADF) material with very high internal quantum efficiency approaching to 100%. This PeLED exhibited improved EL performance with the maximum luminance of 22,063 cd/m², highest current efficiency of 8.74 cd/A and best EQE of 2.26%, which were 3.42, 4.33 and 4.35 times to that of neat CsPbBr₃ film based PeLED, respectively. The enhanced EL performance was enabled by utilization of TADF molecule as the assistant dopant that permitted efficient Förster energy transfer of all electrically generated excitons from the assistant dopant to the excited state of the perovskite emitter.

通过使用CsPbBr ₃：4,5-二（9H-咔唑-9-基）邻苯二甲腈（2CzPN）的混合钙钛矿薄膜发光，证明了一种高效的全无机卤化铯钙钛矿发光二极管（PeLED）。层，其中2CzPN是热激活延迟荧光（TADF）材料，具有非常高的内部量子效率，接近100％。这种PeLED表现出改善的EL性能，最大亮度为22,063 cd / m ²，最高电流效率为8.74 cd / A，最佳EQE为2.26％，是纯CsPbBr _3的3.42、4.33和4.35倍基于电影的PeLED。通过利用TADF分子作为辅助掺杂剂，可以提高EL的性能，从而允许将所有电激发子从辅助掺杂剂高效钙钛矿有效转移到钙钛矿发射体的激发态。