Efficiency roll-off of quantum-dot light-emitting devices (QLEDs) at high brightness severely impedes their commercialization, which is mainly attributed to the difficulty in regulating excessive and imbalanced carrier injection under varying electric fields. In this study, a dynamic self-regulation strategy responsive to external electric fields is proposed, which is realized by integrating nematic liquid crystal molecule 5CB into the electron transport layer. The reorientation of 5CB, triggered by the applied bias, generates a built-in electric field that dynamically modulates electron transport in real time, enabling balanced charge carriers during dynamic operation. As a result, the self-regulated QLEDs achieve a peak external quantum efficiency (EQE) of 26.04% and demonstrate ultrastable efficiency retention, maintaining an EQE of 25.37% even at an extremely high brightness of 100,000 nits. This work offers a novel approach for dynamic control of carriers, paving the way for the development of high-performance QLEDs with outstanding stability.
Lin et al. (Thu,) studied this question.