Phosphorescent organic light-emitting diodes (OLEDs) with high electroluminescence (EL) efficiency and low efficiency roll-off are urgently required to meet the continuously increasing market need in lighting industry fields. There is an urgent demand for phosphorescent emitters with excellent photoluminescence quantum yields (PLQYs) to realize a high EL performance of OLEDs. In this work, four new orange phosphorescent iridium(III) emitters, namely Ir-1–Ir-4, were designed and synthesized successfully, in which functionalized 1,2-diphenylbenzimidazole and conjugated quinoline-benzimidazole moieties are employed as the main ligands and ancillary ligands, respectively. The obtained phosphors show relatively high efficiency and broad full width at half-maximums (FWHMs) of about 110 nm, which are favorable for constructing high-quality white OLEDs. The optimized monochromatic orange-emitting OLED of Ir-1 shows a maximum current efficiency (CE) of 27.2 cd A^–1, a power efficiency of 24.0 lm W^–1, and an external quantum efficiency (EQE) of 10.6%. A two-color OLED employing Ir-1 as the orange-emitting layer shows a maximum brightness of 43980 cd m^–2, a CE of 27.7 cd A^–1, a PE of 21.8 lm W^–1, an EQE of 11.3%, and a low CE efficiency roll-off ratio of 7.9%. Moreover, this device displays warm white emission with CIE coordinates of (0.39, 0.43) at 7 V and high color stability with a CIE variation of (0.003, 0.001).

中文翻译：

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基于简单烷基修饰的橙色铱（III）荧光粉的高性能且稳定的暖白色OLED

迫切需要具有高电致发光（EL）效率和低效率滚降的磷光有机发光二极管（OLED），以满足照明工业领域不断增长的市场需求。迫切需要具有优异的光致发光量子产率（PLQY）的磷光发射体，以实现OLED的高EL性能。在这项工作中，四个新的橙色磷光铱（III）发射器，即Ir-1 – Ir-4分别成功地设计和合成了功能化的1,2-二苯基苯并咪唑和共轭喹啉-苯并咪唑部分作为主要配体和辅助配体。所获得的磷光体显示出相对较高的效率和约110nm的半峰全宽（FWHM），这对于构造高质量的白色OLED是有利的。经过优化的Ir-1单色橙色发光OLED的最大电流效率（CE）为27.2 cd A ^–1，功率效率为24.0 lm W ^–1，外部量子效率（EQE）为10.6％。使用Ir-1作为橙色发射层的双色OLED的最大亮度为43980 cd m ^–2，CE为27.7 cd A^–1，PE为21.8 lm W ^–1，EQE为11.3％，CE效率下降率为7.9％。此外，该设备在7 V电压下显示CIE坐标为（0.39，0.43）的暖白光，CIE变化为（0.003，0.001）时具有很高的色彩稳定性。