Organic light emitting diodes (OLEDs) are emerging key technologies for full-color flat-panel displays and high-quality solid-state lighting sources. To achieve highly efficient OLED devices, the hole injection/transport layer is a key factor. Solution-processed transition metal oxides have promising potential, due to their balanced charge injection and efficient carrier mobility. Herein, we have demonstrated a solution-processed efficient yellow phosphorescent OLED with tungsten trioxide (WO3) hole-injection/hole-transport layer (HIL/HTL). The electroluminescent characteristics of PEDOT:PSS and WO3 based devices were studied. The WO3 based OLED exhibits maximum luminance of 10230 cdm−2, the power efficiency of 35.9 lmW−1, current efficiency 51 cdA−1, and external quantum efficiency of 17.4%. Moreover, the resultant device also displays 45% higher power efficiency as compared to counterpart which exhibits PEDOT:PSS. The higher device performances of OLED device may be attributed to effective hole transporting ability, balanced charge carrier injection in the emissive layer, and non-acidic characteristic of HIL. Analysis of results illustrates an alternative tactic based on tungsten trioxide as a substitute of PEDOT:PSS for solution-processable energy-saving OLEDs.

中文翻译：

---

具有三氧化钨空穴注入/传输层的高效溶液处理黄色有机发光二极管

有机发光二极管 (OLED) 是全彩平板显示器和高质量固态光源的新兴关键技术。为了实现高效的 OLED 器件，空穴注入/传输层是一个关键因素。由于其平衡的电荷注入和有效的载流子迁移率，溶液处理的过渡金属氧化物具有广阔的潜力。在此，我们展示了一种具有三氧化钨 (WO3) 空穴注入/空穴传输层 (HIL/HTL) 的溶液处理的高效黄色磷光 OLED。研究了基于 PEDOT:PSS 和 WO3 的器件的电致发光特性。基于 WO3 的 OLED 的最大亮度为 10230 cdm-2，功率效率为 35.9 lmW-1，电流效率为 51 cdA-1，外量子效率为 17.4%。而且，与显示 PEDOT:PSS 的对应设备相比，所得设备的功率效率也提高了 45%。OLED 器件的更高器件性能可能归因于有效的空穴传输能力、发射层中平衡的电荷载流子注入以及 HIL 的非酸性特性。结果分析说明了基于三氧化钨替代 PEDOT:PSS 的可溶液加工节能 OLED 的替代策略。