Harvesting the Triplet Excitons of Quasi-Two-DimensionalPerovskite toward Highly Efficient White Light-Emitting Diodes

作者：Yu, Yue; Zhao, Chenjing; Ma, Lin; Yan, Lihe; Jiao, Bo; Li, Jingrui; Xi, Jun; Si, Jinhai; Li, Yuren; Xu, Yanmin; Dong, Hua; Dai, Jinfei; Yuan, Fang; Zhu, Peichao; Jen, Alex K. -Y.; Wu, Zhaoxin^*

来源：Journal of Physical Chemistry Letters, 2022, 13(16): 3674-3681.

DOI：10.1021/acs.jpclett.2c00996

• LEAD-HALIDE PEROVSKITES
• ENERGY-TRANSFER
• MECHANISMS
• MANAGEMENT
• FORSTER
• SINGLET

Utilization of triplet excitons, which generally emit poorly, is alwaysfundamental to realize highly efficient organic light-emitting diodes (LEDs). Whiletriplet harvest and energy transfer via electron exchange between triplet donor andacceptor are fully understood in doped organic phosphorescence and delayedfluorescence systems, the utilization and energy transfer of triplet excitons in quasi-two-dimensional (quasi-2D) perovskite are still ambiguous. Here, we use an orange-phosphorescence-emitting ultrathin organic layer to probe triplet behavior in the sky-blue-emitting quasi-2D perovskite. The delicate white LED architecture enables acarefully tailored Dexter-like energy-transfer mode that largely harvests the tripletexcitons in quasi-2D perovskite. Our white organic-inorganic LEDs achieve maximumforward-viewing external quantum efficiency of 8.6% and luminance over 15 000 cdm-2, exhibiting a significant efficiency enhancement versus the corresponding sky-blueperovskite LED (4.6%). The efficient management of energy transfer between excitonsin quasi-2D perovskite and Frenkel excitons in the organic layer opens the door to fullyutilizing excitons for white organic-inorganic LEDs.

• 单位
  西安交通大学; 西安电子科技大学