Efficient InP Green Quantum‐Dot Light‐Emitting Diodes Based on Organic Electron Transport Layer

Abstract

Abstract ZnMgO thin film is commonly used as an electron transport layer (ETL) in quantum‐dot light‐emitting diodes (QLEDs); however, it often induces the problems of interface exciton quenching and electron over‐injection in the devices. Herein, an organic molecule 2,4,6‐tris(3‐(diphenylphosphoryl)phenyl)‐1,3,5‐triazine (PO‐T2T) is investigated as a ETL material for InP green QLEDs. Due to the high injection barrier and moderate electron mobility, the PO‐T2T can prevent electron over‐injection and accumulation in the InP QLEDs. Besides, with the organic ETL, the interfacial exciton quenching is effectively suppressed. By depositing the PO‐T2T using a solution‐assisted evaporation method, efficient InP green QLEDs are achieved, which exhibit a maximum external quantum efficiency of 15.0% and a luminance of 10 010 cd m −2 , corresponding to 211% and 237% enhancements, respectively, compared to 7.1% and 4207 cd m −2 of the devices with ZnMgO ETL.