White organic light-emitting diodes (WOLEDs) with doping-free emissive layer (EML) structures have been increasingly attracting attention due to their excellent advantages, such as easier manufacturing process and more flexible structure design. In this paper, a series of highly efficient hybrid WOLEDs is manufactured using a simple doping-free EML structure, which is composed of two blue thermally activated delayed fluorescence (TADF) emitters and an ultrathin (<0.1 nm) orange phosphorescent emitter. Through the thickness optimization of the blue TADF emitters, the optimal device shows a maximum external quantum efficiency, power efficiency, current efficiency, and luminance of 9.1%, 22.7 lm/W, 29.0 cd/A, and 14 530 cd/m2, respectively. When the brightness is increased from 1000 cd/m2 to 10 000 cd/m2, the chromaticity coordinates migrate from (0.44, 0.48) to (0.41, 0.47), and the correlated color temperature changes from 3454 to 3881 K, which belongs to the warm-white light emission zone. The result indicates that the use of a doping-free blue–orange–blue structure provides a common path for fabricating efficient, simple, and low cost WOLEDs.

中文翻译：

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具有简单的完全无掺杂器件结构的高性能 TADF-磷光混合暖白有机发光二极管

具有无掺杂发光层（EML）结构的白色有机发光二极管（WOLED）因其制造工艺更简单、结构设计更灵活等优异优势而越来越受到关注。在本文中，使用简单的无掺杂 EML 结构制造了一系列高效混合 WOLED，该结构由两个蓝色热激活延迟荧光 (TADF) 发射器和一个超薄 (<0.1 nm) 橙色磷光发射器组成。通过对蓝色 TADF 发射体的厚度优化，优化器件的最大外量子效率、功率效率、电流效率和亮度分别为 9.1%、22.7 lm/W、29.0 cd/A 和 14 530 cd/m2 . 当亮度从 1000 cd/m2 增加到 10 000 cd/m2 时，色度坐标从(0.44, 0.48)迁移到(0.41, 0.47)，相关色温从3454变为3881 K，属于暖白光发射区。结果表明，使用无掺杂的蓝橙蓝结构为制造高效、简单和低成本的 WOLED 提供了一条通用途径。