Incorporating two different chromo-phores onto a silicon atom: the crystal structure and photophysical properties of 9-{4-[(9,9-dimethyl-9H-fluoren-2-yl)-dimethylsilyl]phenyl}-9H-carbazole

摘要

Silicon-bridged compounds have been used as host materials in organic light-emitting diodes (OLEDs) due to their advantageous properties, such as conjugation blocking to give a wide band gap and their tetrahedral geometry which gives an enhanced morphology (Holmes et al., 2003). In particular, they have been utilized in deep-blue phosphorescence devices because they have a relatively high triplet energy state when they are incorporated with a phenylcarbazole group (Han et al., 2009). More recently, the molecular design of bipolar host materials adopting Si atoms as the saturated bridge between two different units, viz. hole-transporting and electron-transporting functional blocks, was reported (Gong, Chen et al. 2011). These compounds incorporated electron-donating and electron-accepting groups on the Si atom and were utilized successfully as universal host materials for multicolour phosphors with high efficiencies.