The hole-injection layer (HIL) has vital impacts on the electroluminescence performance of organic light-emitting diodes (OLEDs). Herein, low-temperature solution-processed Li-doped nickel oxide (Li:NiO_x) was fabricated as a novel HIL for OLEDs. As a result, the phosphorescent green OLED with 5% molar ratio Li:NiO_x exhibits the best performance with low turn-on voltage of 3.1 V, maximum current efficiency of 55.8 cd A⁻¹, maximum power efficiency of 57.2 lm·W⁻¹ and maximum external quantum efficiency of 17.1%. While it is only 52.1 cd A⁻¹, 50.9 lm·W⁻¹ and for the reference device with undoped NiO_x film, corresponding a 7%, 12% and 8% enhancement in efficiency respectively. It reveals that the improved efficiency of the Li:NiO_x film HIL based device with is mainly ascribed to the synergistic effect of extrinsic doping in the aspects of achieving enhanced hole injection. Our work demonstrates that the solution-processed Li-doped NiO_x film is a promising HIL for high-performance OLEDs.

空穴注入层（HIL）对有机发光二极管（OLED）的电致发光性能具有至关重要的影响。在此，低温溶液处理的掺杂锂的氧化镍（Li：NiO _x）被制造为用于OLED的新型HIL。结果，Li：NiO _x摩尔比为5％的磷光绿色OLED在3.1 V的低导通电压，55.8 cd A ^-1的最大电流效率，57.2 lm·W-的最大功率效率下表现出最佳性能^{。 1}，最大外部量子效率为17.1％。虽然只52.1光盘^-1，50.9流明^{·W -1}和用于与未掺杂的NiO参考装置_X薄膜的效率分别提高了7％，12％和8％。它揭示了Li的改进的效率：氧化镍_X基于膜HIL设备与主要归因于非本征掺杂的在实现增强的空穴注入的所述方面的协同效应。我们的工作表明，经溶液处理的掺锂NiO _x膜是用于高性能OLED的有前途的HIL。