Four novel bipolar hosts (DTAFNBI, m-DTAFNBI, DTAFCBI and m-DTAFCBI) comprising a hole-transport ditolylphenylamino donor and an electron-transport 1,2-diphenylbenzimidazole acceptor connected via a fluorene spacer were synthesized and characterized. Through the different linkage topologies of phenylbenzimidazole, the thermal, photophysical, and electrochemical properties can be fine-tuned. The saturated fluorene spacer along with the ditolylphenylamino donor and the phenylbenzimidazole acceptor endowed high triplet energies (E_T = 2.47–2.62 eV, recorded in neat film at 20 K) and bipolar transporting abilities. Furthermore, the tetragonal geometry given by the sp³-hybridized C9 of fluorene encumbered intermolecular packing and led to excellent thermal and morphological stabilities (T_d = 379–392 °C, corresponding 5% weight loss; T_g = 148–162 °C). As a result, these bipolar materials were utilized as universal hosts for red, yellow, and blue (RYB) phosphorescent OLEDs, showing maximum external quantum efficiencies (η_ext) of 9.6%, 14.7%, and 18.9% for blue (FIrpic), yellow (m-(Tpm)₂Ir(acac) and red [Os(bpftz)₂(PPhMe₂)₂, OS1], respectively. In addition, white organic light-emitting diodes combining a blue emitter (FIrpic) and yellow emitter m-(Tpm)₂Ir(acac) and a red emitter (OS1) within a single emitting layer were also fabricated which also exhibited good efficiencies (9.5–13.7%, 15.1–23.5 cd A⁻¹, 13.3–23.9 lm W⁻¹) with relatively low efficiency roll off.

合成并表征了四种新颖的双极主体（DTAFNBI，m - DTAFNBI，DTAFCBI和m - DTAFCBI），该主体包括空穴传输的二甲苯基苯基氨基供体和一个通过芴间隔基连接的电子传输的1,2-二苯基苯并咪唑受体。通过苯基苯并咪唑的不同键合拓扑，可以对热，光物理和电化学性质进行微调。饱和芴间隔基以及二甲苯基苯基氨基供体和苯基苯并咪唑受体赋予了较高的三重态能量（E _T = 2.47–2.62 eV，记录在20 K下的纯净膜中）和双极传输能力。此外，芴的sp ^3-杂化C9给出的四边形几何结构阻碍了分子间堆积，并导致出色的热稳定性和形态稳定性（T _d  = 379–392°C，相应的重量损失5％；T _g  = 148–162°C ）。其结果是，这些双极性材料用作用于红，黄，蓝（RYB）磷光OLED通用主机，显示出最大外部量子效率（η _EXT用于蓝色（的FIrpic）的9.6％，14.7％，和18.9％），黄色（m-（Tpm）₂ Ir（acac）和红色[Os（bpftz）₂（PPhMe ₂）₂，OS1]。此外，还制作了在单个发光层中结合了蓝色发射器（FIrpic）和黄色发射器m-（Tpm）₂ Ir（acac）和红色发射器（OS1）的白色有机发光二极管，它们也显示出良好的效率（ 9.5-13.7％，15.1-23.5光盘^-1，13.3-23.9流明w ^ ^-1）具有相对低的效率滚降。