Ultrahighly Efficient White Quantum Dot Light‐Emitting Diodes Operating at Low Voltage
Yangbin Zhu, Rui Xu, Yuangui Zhou, Zhongwei Xu, Yang Liu, Fengqing Tian, Xiaojing Zheng, Fumin Ma, Rashed Alsharafi, Hailong Hu, Tailiang Guo, Tae Whan Kim, Fushan Li
Abstract
Abstract Achieving efficient white quantum dot light‐emitting diodes (WQLEDs) is highly desired because of their promising applications in general illumination and display backlight systems. Herein, a highly efficient WQLED with an extremely low input voltage is reported, which is fabricated via an all‐solution process by using an emitting layer with a mixture of red‐, blue‐, and green‐emitting quantum dots. When a facile strategy of light outcoupling with an optical lens is introduced, the device shows a maximum external quantum efficiency of 28.4%, which is the highest value reported so far. Moreover, the device exhibits a standard white emission with International Commission on Illumination (CIE) coordinates of (0.36, 0.34) at an extremely low input voltage of 3.2 V. This work provides a promising way for achieving high‐performance white quantum‐dot light‐emitting diodes with low driving voltage.