High thermal stability is of pivotal significance for hole transport materials (HTMs) owing to thermal evaporation and device operation stability requirements. In this study, two new HTMs, namely FCzTPA and FCzDPNA, were developed by using easily accessible carbazole/dibenzo[b,d]furan derivatives. The rigid structures bring about excellent thermal stability, with a decomposition temperature (T_d) of up to 400 °C and glass transition temperature (T_g) above 190 °C. Moreover, benefiting from the twisted spatial configuration and constituent units, they both exhibit suitable triplet energy levels (E_T = 2.56, 2.74 eV). When hosting red phosphorescent organic light emitting diodes (PhOLEDs), the FCzTPA-based device shows a turn-on voltage (V_on) of 3.4 V and the maximum external efficiency (EQE_max) of 18.61%, indicating that the synthetic compounds are potential building blocks for highly efficient OLEDs.

中文翻译：

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具有高热稳定性的咔唑和二苯并[b,d]呋喃基空穴传输材料

由于热蒸发和器件运行稳定性要求，高热稳定性对空穴传输材料 (HTM) 具有关键意义。在这项研究中，两种新的 HTM，即FCzTPA和FCzDPNA，是通过使用易于获得的咔唑/二苯并 [ b , d ] 呋喃衍生物开发的。刚性结构带来出色的热稳定性，分解温度 ( T _d ) 高达 400 °C，玻璃化转变温度 ( T _g ) 高于 190 °C。此外，受益于扭曲的空间配置和组成单元，它们都表现出合适的三重态能级（E _T= 2.56、2.74 电子伏特）。当承载红色磷光有机发光二极管 (PhOLED) 时，基于FCzTPA的器件显示 3.4 V 的开启电压 ( V _on ) 和 18.61% 的最大外部效率 (EQE _max )，表明合成化合物具有潜力构建高效 OLED 的模块。