Fluorenyl Aromatic Phosphonic Oxygen Electro-active Materials Design And Synthesis

Electrophosphorescence and the corresponding devices have attracted much interest with great applicable potentials in digital terminal displays and planar solid-state lighting. At present, the recognized bottleneck in this field is the lack of low driving voltage and high, stable and efficient blue emitting devices. All of these problems can be solved if we can find a way to construct the highly efficient blue material with excellent carrier injecting/transporting ability, but not affect chromophores inherent properties. Based on unique insulating and electroactive property of aryl phosphine oxides (APO) derivatives, this thesis demonstrated an efficient strategy of indirect linkage to construct highly efficient blue organic electroluminescent materials.1. APO was introducted into fluorene through its9position. We designed and synthesized APO-substituted template molecules:FSPO, FDPO and FSPO2. The experimental results showed that the strategy of indirect linkage can both effectively keep first triplet energy level (Ti) of chromophores (2.99eV) and improve the carrier transporting performance of materials. The maximum efficiencies of blue-emitting phosphorescent organic light-emitting devices (PHOLEDs) based on FSPO and FDPO as host materials were respectively12.5lm/W and13.8lm/W for power efficiency and14.5cd/A and14.6cd/A for current efficiency, respectively.2. Hole-transporting moieties were introducted into FSPO through9position of fluorene.We designed and synthesized ternary ambipolar, highly Efficient phosphine oxide materials (9ArFSPO). The experimental results showed that strategy of indirect linkage can more effectively restrain interplays between different moieties in the molecules which maintain inherent excellent properties of different moieties and restrain Triplet-Ttriplet Annihilate (TTA) and concentration quenching. Ti was3.0eV. The maximum efficiencies of blue-emitting devices based on9CzFSPO as host materials were35.6lm/W for P.E.,35.5cd/A for C.E. and14.4%for E.Q.E.. The fluorescent devices based on9DPNAFSPO realized the deep blue emission with CIE of (0.15,0.07) and high E.Q.E. of1.96%.3. Hole-transporting moieties were introducted into FSPO and FDPO through2,7position of fluorene. We designed and synthesized ternary ambipolar, highly efficient APO materials:FSPOArn and FDPOArn (n=1or2). Through changing the type, number and substitution position, the excited states can be tuned. A series deep-blue emitting phosphors and the continuously modulated Ti from2.9to2.5eV with ambipolar ternary functional materials were achieved.