Ultra‐Fast Response Near‐Infrared Perovskite Quantum Dot Light‐Emitting/Sensing Device for Near Eye Interactive Display

ABSTRACT Near‐infrared perovskite quantum dot light‐emitting diodes (NIR‐PeLEDs) hold great potential for near‐eye interactive displays. Developing devices with light‐emitting/sensing dual functionality would facilitate their integration into augmented and virtual reality systems. However, the slow response speed of conventional NIR‐PeLEDs fundamentally limits their use in real‐time interactive applications such as eye‐tracking and gesture recognition, impairing immersive experiences. In this work, we systematically study the electroluminescence response of NIR‐PeLEDs under pulsed operation. By employing a self‐assembled hole‐injection layer of (2‐(3,6‐dibromo‐9H‐carbazol‐9‐yl)ethyl)phosphonic acid (Br‐2PACz) and optimizing the emission area, we achieve a record‐fast steady‐state electroluminescence response time of 23 ns at a low drive voltage of 6 V, without the need for high current density that compromise stability. Furthermore, the device exhibits a rapid photo‐response in self‐powered mode, with a photocurrent rise time of 43 ns, demonstrating dual nanosecond‐scale emission and detection capabilities. Culminating in a flexible NIR‐PeLEDs with a resolution of 9072 pixel per inch, this work showcases a viable path toward wearable interactive displays and provides a critical design reference for high‐speed, multifunctional perovskite optoelectronics.