Yao Zhiwei, Bi Chenghao, Xu Rui, Zhang Xuanyu, Qian Lei, Xiang Chaoyu
Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Science, Ningbo, Zhejiang, 315201, China.
Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315300, China.
Adv Mater. 2025 Aug 4:e20131. doi: 10.1002/adma.202420131.
Pure blue emission (wavelength ≤ 470 nm) is essential for perovskite light-emitting diodes (PeLEDs) in the application of future displays. However, the performance of the pure blue PeLEDs is far away from the application requirement and theoretical values. The charging of excitons plays a crucial role in the non-radiative decay of the high-energy blue perovskite emitters under electric fields. Here, a designed exciton-carrier decoupling emitting layer (De-EML) is reported which can simultaneously suppress the formation of charged excitons and facilitate the injection of carriers. By tuning the energy levels of each QD layer in the De-EML, the photoluminescence quantum yield (PLQY) reached 83.7%, and the Auger recombination related to exciton-carrier coupling in high excitation intensities is suppressed. Based on the designed De-EML, high-performance pure-blue PeLEDs (emission at 469 nm) with an EQE of 20.3% and an operational lifetime (T) of 4.8 h at 1070 cd m is demonstrated. A record maximum brightness of 31 407 cd m is also achieved.
纯蓝光发射（波长≤470纳米）对于钙钛矿发光二极管（PeLED）在未来显示器应用中至关重要。然而，纯蓝色PeLED的性能远未达到应用要求和理论值。在电场作用下，激子的电荷化在高能蓝色钙钛矿发光体的非辐射衰减中起着关键作用。在此，报道了一种设计的激子-载流子解耦发射层（De-EML），它可以同时抑制带电激子的形成并促进载流子的注入。通过调节De-EML中每个量子点层的能级，光致发光量子产率（PLQY）达到83.7%，并且在高激发强度下与激子-载流子耦合相关的俄歇复合受到抑制。基于所设计的De-EML，展示了高性能的纯蓝色PeLED（发射波长为469纳米），其外量子效率（EQE）为20.3%，在1070坎德拉每平方米的亮度下工作寿命（T）为4.8小时。还实现了创纪录的31407坎德拉每平方米的最大亮度。
