A new series of 2,8-disubstituted dibenzothiophenes have been successfully synthesized via palladium-catalyzed C–N or C–C bond formation using 2,8-dibromodibenzothiophene and diarylamines as starting materials. These new dibenzothiophene derivatives are amorphous with a glass transition temperature ranging from 86 to 190 °C. Furthermore, they are fluorescent in the blue to bluish green region. Two types of light-emitting diodes (LED) were constructed from these compounds, (I) ITO/Cpd/TPBI/LiF/Al and (II) ITO/Cpd/Alq3/LiF/Al, where TPBI and Alq3 are 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene and tris(8-hydroxyquinolinato)aluminium, respectively. In type I devices, the compounds function as the hole-transporting and emitting material. In type II devices, emission from Alq3 is observed. Several type I devices emit pure blue light, and most of the devices II have very promising performance. The relation between the energy levels of the materials and the performance of the light-emitting diodes is discussed.
以
2,8-二溴二苯并噻吩和二芳基胺为起始原料,通过
钯催化 C-N 或 C-C 键的形成,成功合成了一系列新的 2,8-二取代
二苯并噻吩。这些新的
二苯并噻吩衍
生物是无定形的,
玻璃化转变温度为 86 至 190 ℃。此外,它们还具有蓝色至蓝绿色荧光。利用这些化合物构建了两种类型的发光二极管(LED):(I)ITO/Cpd/TPBI/
LiF/Al 和(II)ITO/Cpd/Alq3/
LiF/Al,其中 TPBI 和 Alq3 分别是 1,3,5-三(N-苯基
苯并咪唑-2-基)苯和三(
8-羟基喹啉)铝。在 I 型器件中,这些化合物起着空穴传输和发射材料的作用。在 II 型器件中,可观察到 Alq3 的发射。有几个 I 型器件能发出纯蓝光,而大多数 II 型器件的性能都很不错。本文讨论了材料能级与发光二极管性能之间的关系。