Improving power efficiency (PE) and reducing roll-off are of significant importance for the commercialization of white organic light-emitting diodes (WOLEDs) in consideration of energy conservation. Herein, record-beating PE of 130.7 lm W⁻¹ and outstanding external quantum efficiency (EQE) of 31.1% are achieved in all-fluorescence two-color WOLEDs based on a simple sandwich configuration of emitting layer consisting of sky-blue and orange delayed fluorescence materials. By introducing a red fluorescence dopant, all-fluorescence three-color WOLEDs with high color rendering index are constructed based on an interlayer sensitization configuration, furnishing ultrahigh PE of 110.7 lm W⁻¹ and EQE of 30.8%. More importantly, both two-color and three-color WOLEDs maintain excellent PEs at operating luminance with smaller roll-offs than the reported state-of-the-art WOLEDs, and further device optimization realizes outstanding comprehensive performances of low driving voltages, large luminance, high PEs and long operational lifetimes. The underlying mechanisms of the impressive device performances are elucidated by host-tuning effect and electron-trapping effect, providing useful guidance for the development of energy-conserving all-fluorescence WOLEDs.

考虑到节能，提高功率效率（PE）和减少滚降对于白色有机发光二极管（WOLED）的商业化具有重要意义。在此，基于由天蓝色和橙色延迟组成的发射层的简单三明治配置，全荧光双色 WOLED 实现了创纪录的 130.7 lm W ^-1的PE和 31.1% 的出色外量子效率 ( EQE )荧光材料。通过引入红色荧光掺杂剂，基于层间敏化配置构建了具有高显色指数的全荧光三色WOLED，提供110.7 lm W ^-1的超高PE和30.8% 的EQE。更重要的是，双色和三色 WOLED 在工作亮度下均保持了出色的PE s，并且滚降比报道的最先进的 WOLED 更小，进一步的器件优化实现了低驱动电压、大亮度、高PE和长使用寿命。通过宿主调谐效应和电子俘获效应阐明了令人印象深刻的器件性能的潜在机制，为节能全荧光 WOLED 的开发提供了有用的指导。