Abstract Metal-doped ZnO, as an alternative to indium tin oxide, has been extensively investigated; however, its widespread use has been limited because of its low conductivity and work function. In this study, ZnO was Ni-doped via co-sputtering to achieve work function tuning and improve its conductivity. The Ni-doped ZnO could be used as an effective hole injection electrode for organic light-emitting diodes (OLEDs). Herein, we prepared a Ni-doped ZnO/Ag/ZnO (Ni:ZAZ) electrode for thermally activated delayed fluorescence-based flexible blue OLEDs. The Ni:ZAZ electrode exhibited outstanding performance with a surface resistivity of 6.33 Ω/sq, high transmittance of 93.3% at 484 nm, and work function of up to 0.6 eV, along with a smooth surface and excellent mechanical durability. In addition, the Ni:ZAZ-based OLEDs exhibited excellent performance with a turn-on voltage of 3.0 V and a maximum current efficiency of 17.2 cd/A owing to its improved hole injection property. Furthermore, on flexible substrates, these OLEDs exhibited improved mechanical stability even after being subjected to 2000 bending cycles at a radius of curvature of 6 mm. Thus, the synthesis approach proposed in this study will pave a new pathway for the development of transparent electrodes for flexible and wearable opto-electronic devices.

中文翻译：

---

功函数可调的 ZnO/Ag/ZnO 薄膜作为一种有效的空穴注入电极，通过镍掺杂制备，用于热激活延迟荧光基柔性蓝色有机发光二极管

摘要 金属掺杂的 ZnO 作为氧化铟锡的替代品已被广泛研究。然而，由于其低电导率和低功函数，其广泛应用受到限制。在这项研究中，通过共溅射对 ZnO 进行 Ni 掺杂，以实现功函数调整并提高其导电性。Ni掺杂的ZnO可用作有机发光二极管（OLED）的有效空穴注入电极。在此，我们制备了用于热激活延迟荧光基柔性蓝色 OLED 的 Ni 掺杂 ZnO/Ag/ZnO（Ni:ZAZ）电极。Ni:ZAZ 电极表现出优异的性能，表面电阻率为 6.33 Ω/sq，484 nm 处的透光率高达 93.3%，功函数高达 0.6 eV，表面光滑，机械耐久性优异。此外，Ni：基于 ZAZ 的 OLED 表现出优异的性能，由于其改进的空穴注入性能，其开启电压为 3.0 V，最大电流效率为 17.2 cd/A。此外，在柔性基板上，这些 OLED 甚至在以 6 毫米的曲率半径经受 2000 次弯曲循环后仍表现出改善的机械稳定性。因此，本研究中提出的合成方法将为开发用于柔性和可穿戴光电设备的透明电极铺平道路。