Organic light-emitting diodes (OLEDs) attract much research attention owing to their superior device characteristics in display and lighting applications. However, multi-layered organic thin films deposited by thermal evaporation in a high-vacuum chamber complicate the fabrication processes and increase the production costs. Alternatively, solution-processable single-layered light-emitting electrochemical cells (LECs) possess easy fabrication and good device performance due to in situ electrochemical doping. To take advantages of both types of devices, the study proposes an efficient tandem white OLED/LEC hybrid device by stacking a red OLED on top of a blue LEC with a sophisticatedly designed charge-generating layer (CGL). The proposed tandem device exhibits a high external quantum efficiency (EQE) of 21.53%, which is almost the sum of the EQEs of the two stacked devices. When fabricated on the diffusive substrate to recycle the trapped light in the substrate, the EQE can be further enhanced to reach 37.88%. Besides connecting the two stacked devices, the CGL improves the carrier balance of the blue LEC due to enhanced electron injection. This study demonstrates that the white tandem OLED/LEC hybrid device has a simpler device structure than all-vacuum-processed tandem OLEDs but it still delivers high device efficiency, revealing its potential in lighting applications.

中文翻译：

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高效串联白光 OLED/LEC 混合器件

有机发光二极管（OLED）由于其在显示和照明应用中优异的器件特性而引起了广泛的研究关注。然而，在高真空室中通过热蒸发沉积的多层有机薄膜使制造工艺复杂化并增加了生产成本。另外，可溶液加工的单层发光电化学电池（LEC）由于原位电化学掺杂而具有易于制造和良好的器件性能。为了充分利用这两种类型的器件，该研究提出了一种高效的串联白色 OLED/LEC 混合器件，通过将红色 OLED 堆叠在具有精心设计的电荷生成层 (CGL) 的蓝色 LEC 顶部。所提出的串联器件表现出高达 21.53% 的外量子效率 (EQE)，这几乎是两个堆叠器件的 EQE 之和。当制作在扩散基板上以回收基板中的捕获光时，EQE可以进一步增强，达到37.88%。除了连接两个堆叠器件外，CGL 还通过增强电子注入改善了蓝色 LEC 的载流子平衡。这项研究表明，白色串联 OLED/LEC 混合器件比全真空处理的串联 OLED 具有更简单的器件结构，但仍然具有较高的器件效率，揭示了其在照明应用中的潜力。