By melting tetraphenylethene (TPE) and 1,2,4,5-tetraphenyl-1H-imidazole (TPI) units together through different linking positions, three new fluorophores are synthesized, and their optical, electronic and electroluminescence (EL) properties are fully studied. Owing to the presence of TPE unit(s), these fluorophores are weak emitters in solutions, but are induced to emit strongly in the aggregated state, presenting typical aggregation-induced emission characteristics. The experimental and computational results reveal that different connection patterns between TPE and TPI could impact the molecular conjugation greatly, leading to varied emission wavelength, fluorescence quantum yield and EL performance in organic light emitting diodes (OLEDs). The fluorophore built by attaching TPE unit to the 1-position of imidazole ring shows bluest fluorescence, and its EL device emits at deep blue region (445 nm; CIE = (0.16, 0.15)). And the device based on the fluorophore by linking TPE to the 2- position of imidazole ring shows EL at 467 nm (CIE = (0.17, 0.22)) with good efficiencies of 3.17 cd·A–1, and 1.77%.

8-羟基喹啉铝类有机金属配合物作为一类重要的发光材料广受关注。 文章合成并通过真空升华提纯得到了一种高纯度的8-羟基喹啉铝的衍生物-三(2-甲基-8-羟基喹啉)铝, 通过红外光谱、 核磁共振谱以及元素分析确定了三(2-甲基-8-羟基喹啉)铝的分子结构。 通过热重和差示扫描量热分析研究了三(2-甲基-8-羟基喹啉)铝的热稳定性, 试验结果表明： 此衍生物的结晶转变温度可达158 ℃, 分解温度为357 ℃; 并进一步通过紫外可见吸收光谱和荧光光谱表征了材料的带隙以及能带结构。 将吸收边的线性关系延伸到与能量轴相交所得禁带宽度2.85 eV, 三(2-甲基-8-羟基喹啉)铝在365 nm紫外光的激发下, 在乙醇溶液体系中的荧光发射峰在479 nm处, 为蓝色荧光, 荧光量子效率高, 是一种蓝光发射的优选材料。

以一种新型联苯乙烯衍生物NPVBi作为发光层,制备了结构为:ITO/TPD/NPVBi/Alq??3/LiF/Al的有机薄膜电致发光器件,其中TPD厚度保持为50 nm,NPVBi与Alq??3厚度之和保持为50 nm。通过调节NPVBi与Alq??3的厚度,获得了色纯度较好的NPVBi蓝色电致发光,最高亮度为708 cd/m??2,最大流明效率为1.13 lm/W。结果表明,发光层NPVBi和电子传输层Alq??3的厚度对器件的发光特性有显著的影响。