Flexible transparent electrode materials such as conducting polymers, silver nanowires, carbon nanotubes and graphenes are being investigated as possible replacements for conventional brittle inorganic electrodes. However, they have critical drawbacks of low work function (WF), resulting in a high hole injection barrier to an overlying semiconducting layer in simplified organic or organic–inorganic hybrid perovskite light-emitting diodes (OLEDs or PeLEDs). Here, we report a new anode material (AnoHIL) that has multifunction of both an anode and a hole injection layer (HIL) as a single layer. The AnoHIL has easy WF tunability up to 5.8 eV and thus makes ohmic contact without any HIL. We applied our anodes to simplified OLEDs, resulting in very high efficiency (62% ph el⁻¹ for single and 88% ph el⁻¹ for tandem). The AnoHIL showed a similar tendency in simplified PeLEDs, implying universal applicability to various optoelectronics. We also demonstrated large-area flexible lightings using our anodes. Our results provide a significant step toward the next generation of high-performance simplified indium tin oxide (ITO)-free light-emitting diodes.

正在研究诸如导电聚合物，银纳米线，碳纳米管和石墨烯之类的柔性透明电极材料，以替代常规的脆性无机电极。然而，它们具有低功函（WF）的严重缺陷，导致在简化的有机或有机-无机混合钙钛矿发光二极管（OLED或PeLED）中对上覆的半导体层形成高空穴注入势垒。在这里，我们报告了一种新的阳极材料（AnoHIL），它具有阳极和空穴注入层（HIL）的多功能性。AnoHIL具有高达5.8 eV的WF易调谐性，因此无需任何HIL即可进行欧姆接触。我们将阳极应用于简化的OLED，从而获得了非常高的效率（单个像素的phel ^-1和phel ^-1的88％）（一前一后）。AnoHIL在简化的PeLED中也显示出类似的趋势，这暗示了其对各种光电技术的普遍适用性。我们还演示了使用阳极的大面积柔性照明。我们的结果为迈向下一代高性能，简化的无铟锡氧化物（ITO）发光二极管迈出了重要的一步。