Blue phosphorescent organic light-emitting diodes (PhOLEDs) can deliver superior electroluminescence efficiencies than blue fluorescent OLEDs; however, their commercial debut has been delayed by short device lifetimes, especially for deep-blue PhOLEDs with Commission International de l’Eclairage y co-ordinates of less than 0.20. Here we report the use of new dopant and host materials to create a blue PhOLED device with a y co-ordinate of 0.197 and a long device lifetime of LT₇₀ = 1,113 h [Initial luminance (L₀) = 1,000 cd m^–2]. Introducing bulky 3,5-di-tert-butyl-phenyl into the N-heterocyclic carbene moiety in the Pt(II) complex enhanced the photochemical stability of the high-lying metal-centred triplet state and prevented undesirable host–guest interactions, contributing to a longer device lifetime and higher colour purity. For the exciplex-forming host, the hole-transporting and electron-transporting host materials utilized a triphenylsilyl group for enhanced stability, which also improved the device lifetime.

蓝色磷光有机发光二极管 (PhOLED) 可以提供比蓝色荧光 OLED 更高的电致发光效率；然而，它们的商业首次亮相因器件寿命短而被推迟，特别是对于国际委员会 de l'Eclairage y坐标小于 0.20 的深蓝色 PhOLED。在这里，我们报告了使用新的掺杂剂和主体材料来制造蓝色 PhOLED 器件，其y坐标为 0.197，器件寿命长 LT ₇₀  = 1,113 h [初始亮度 ( L ₀ ) = 1,000 cd m ^–2 ] . 将体积庞大的 3,5-二叔丁基苯基引入NPt(II) 配合物中的杂环卡宾部分增强了以金属为中心的高位三重态的光化学稳定性，并防止了不良的主客体相互作用，有助于延长器件寿命和提高色纯度。对于形成激子复合物的主体，空穴传输和电子传输主体材料利用三苯基甲硅烷基来增强稳定性，这也提高了器件寿命。