In this study, two new dibenzofuran derivatives featuring one or two cyanocarbazole units, 6‐(dibenzo[b,d]furan‐4‐yl)‐9‐phenyl‐9H‐carbazole‐3‐carbonitrile (mBFCzCN) and 6,6′‐(dibenzo[b,d]furan‐4,6‐diyl)bis(9‐phenyl‐9H‐carbazole‐3‐carbonitrile) (dBFCzCN), were developed as host materials for phosphorescent organic light emitting diodes (PhOLEDs). A new molecular design connecting the cyanocarbazole to the dibenzofuran using the cyanocarbazole 6‐position instead of its 9‐position was created, and the effects of number of cyanocarbazole units in the dibenzofuran building block on the photophysical and electroluminescence properties were investigated in detail. The mBFCzCN compound revealed high triplet energy (2.78 eV) than that of dBFCzCN (2.68 eV) and good bipolar charge transporting properties. The potential of these materials as hosts for blue and green PhOLEDs was investigated using bis(4,6‐(difluorophenyl)pyridinato‐N,C^2′)picolinate iridium(III) (FIrpic) and tris(2‐phenylpyridinato)iridium(III) (Ir(ppy)₃) dopants, respectively. The results indicated that the mBFCzCN with one cyanocarbazole unit showed better device performance than the dBFCzCN with two cyanocarbazole units in the blue and green devices. High external quantum efficiencies of 19.0 and 21.2 % were demonstrated in the blue and green PhOLEDs with the mBFCzCN host due to its high triplet energy and good bipolar charge transporting characteristics.

中文翻译：

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氰基咔唑通过6-位修饰作为高三重态能量双极主体材料的分子设计方法，对二苯并呋喃进行装饰

在这项研究中，两个新的具有一个或两个氰基咔唑单元的二苯并呋喃衍生物，即6-（二苯并[b，d]呋喃-4-基）-9-苯基-9 H-咔唑-3-腈（mBFCzCN）和6,6 ' - （二苯并[b，d]呋喃-4,6-二基）双（9-苯基-9- ħ -咔唑-3-腈）（dBFCzCN），被开发作为主体材料的磷光有机发光二极管（PHOLED中） 。建立了使用氰基咔唑6位而不是9位将氰基咔唑与二苯并呋喃连接的新分子设计，并详细研究了二苯并呋喃结构单元中氰基咔唑单元数量对光物理和电致发光性质的影响。该mBFCzCN该化合物显示出比dBFCzCN（2.68 eV）高的三重态能量（2.78 eV）和良好的双极性电荷传输性质。使用双（4,6-（二氟苯基）吡啶鎓-N，C ^2'）吡啶甲酸铱（III）和三（2-苯基吡啶鎓）铱（III）研究了这些材料作为蓝色和绿色PhOLED主体的潜力）（Ir（ppy）₃）掺杂剂。结果表明，在蓝色和绿色器件中，具有一个氰基咔唑单元的mBFCzCN显示出比具有两个氰基咔唑单元的dBFCzCN更好的器件性能。蓝色和绿色的PhOLED具有较高的外部量子效率19.0和21.2％。mBFCzCN主体具有高三重态能量和良好的双极电荷传输特性。