Electron injection governs electro-optic performance of organic light-emitting diodes (OLEDs) with intractable inverted architecture. Solution process with low cost and scalable manufacturing drives a lab-to-fab journey of electron injection layer (EIL) in OLEDs. Herein, a facilely solution-processed composite EIL of ZnO + Cs₂CO₃ with robust electron injection has been explored for constructing ultraviolet OLED with inverted architecture. Using 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole as emitter, attractive short-wavelength emission of 380 nm and full-width at half-maximum of 37 nm are demonstrated in the inverted ultraviolet OLED. It achieves maximum radiance of 2.42 mW/cm² and external quantum efficiency of 0.85% with improved operation durability, which are superior or comparable to the corresponding references using single EILs of Cs₂CO₃, ZnO and LiF, or double-stacked EIL of ZnO/Cs₂CO₃. X-ray photoelectron spectroscopy analysis clarifies that the Cs₂CO₃, ZnO and ZnO + Cs₂CO₃ exhibit exceptional electronic properties. The current-voltage characteristics and impedance spectroscopy analysis of electron-only cells confirm that ZnO + Cs₂CO₃ behaves robust electron injection and accounts for excellent device performance. Our results pave an alternative approach for advancing ultraviolet OLED with inverted architecture and facile solution process.

电子注入控制具有难处理的倒置结构的有机发光二极管（OLED）的电光性能。具有低成本和可扩展制造的解决方案工艺推动了OLED中电子注入层（EIL）从实验室到工厂的发展。在本文中，已经探索了通过强力电子注入方便地溶液处理的ZnO + Cs ₂ CO _3的复合EIL，以构建具有反向结构的紫外线OLED。使用3-（4-联苯）-4-苯基-5-叔丁基苯基-1,2,4-三唑作为发射体，证实了380 nm的有吸引力的短波发射和37 nm的半峰全宽在倒置紫外线OLED中。最大辐射度为2.42 mW / cm ²外部量子效率为0.85％，具有更高的工作耐用性，与使用Cs ₂ CO ₃，ZnO和LiF的单个EIL或ZnO / Cs ₂ CO _3的双堆叠EIL相比，具有更好的性能或与之相对应。X射线光电子能谱分析表明，Cs ₂ CO ₃，ZnO和ZnO + Cs ₂ CO ₃具有优异的电子性能。仅电子电池的电流-电压特性和阻抗谱分析证实了ZnO + Cs ₂ CO ₃表现出强大的电子注入性能，并具有出色的器件性能。我们的研究结果为采用倒置结构和简便的溶液工艺推进紫外线OLED铺平了道路。