Abstract:
In this study, a series of ladder-like polysiloxanes are synthesized by introducing double-chain Si-O-Si polymer as the backbone and the carbazole and triphenylphosphine oxide with high triplet energy as side groups. The ladder-like structures of polysiloxanes are achieved through a controlled polymerization method that involves the monomer self-assembly and subsequent surface-restricted solid-phase in situ condensation through freeze-drying. The introduction of siloxane improves thermal stability of the polymers and inhibits the conjugation of the polymers between the side groups, leading to an increase in the triplet energy level. Therefore, all these polymers perform higher triplet energy levels than phosphorescent emitter (FIrpic). The cyclic voltammetry measurements demonstrate that the bipolar polymer exhibits a high highest occupied molecular orbital (HOMO) value of -5.32 eV, which is consistent with the work function of ITO/PEDOT:PSS, consequently facilitating hole injection. Furthermore, the incorporation of triphenylphosphine oxide promotes electron injection. Molecular simulations reveal that the frontier orbital distributions of the bipolar polymer are located on the carbazole and triphenylphosphine groups, respectively, which facilitate the transport of electrons and holes.
摘要:
在这项研究中,通过引入双链Si-O-Si聚合物作为主链,并以具有高三重态能量的咔唑和三苯基氧化膦作为侧基,合成了一系列梯状聚硅氧烷。聚硅氧烷的梯状结构是通过受控聚合方法实现的,该方法包括单体自组装和随后的表面限制的固相通过冷冻干燥原位缩合。硅氧烷的引入提高了聚合物的热稳定性并抑制了侧基之间聚合物的共轭。导致三重态能级的增加。因此,所有这些聚合物执行比磷光发射体(FIrpic)更高的三重态能级。循环伏安法测量表明,双极聚合物表现出高的最高占据分子轨道(HOMO)值-5.32eV,这与ITO/PEDOT:PSS的功函数一致,从而促进空穴注入。此外,三苯基膦氧化物的掺入促进电子注入。分子模拟表明,双极聚合物的前沿轨道分布位于咔唑和三苯基膦基团上,分别,促进电子和空穴的传输。本文受版权保护。保留所有权利。