High-efficiency quantum dot light-emitting devices with dual hole injection layers

Abstract

Quantum dot light-emitting devices (QLEDs) exhibit unique advantages for high-resolution display applications. However, as pixel size decreases, challenges including insufficient hole injection and leakage current become increasingly pronounced, resulting in significant degradation in device performance. Herein, dual hole injection layers are constructed by self-assembly of an organic small molecular layer on conventional PEDOT:PSS to smooth the potential barrier, thus achieving more balanced carrier injection. An ultrafine inter-pixel isolation structure is designed as a charge blocking layer surrounding the photolithograpic pixels, with the purpose of effectively mitigating leakage current in the non-emitting region. The high-resolution devices show a high external quantum efficiency (EQE) of 19.6 % and a peak power efficiency (PE) of 20.63 lm/W, both of which significantly exceed the performance of the control device (EQE = 14.6 %, PE = 10.54 lm/W).