Hexaphenylphenylene dendronised pyrenylamines for efficient organic light-emitting diodes
作者:K. R. Justin Thomas、M. Velusamy、Jiann T. Lin、C. H. Chuen、Yu-Tai Tao
DOI:10.1039/b509325b
日期:——
A series of blue-emitting triarylamines containing pyrene and hexaphenylbenzene dendrons were successfully synthesized by employing the Diels–Alder and palladium catalyzed C–N coupling reactions. They display high glass transition temperatures (>140 °C) in differential scanning calorimetry and facile reversible oxidation couple in cyclic voltammetry. They are also thermally stable exhibiting decomposition temperature above 385 °C. Efficient blue-emitting electroluminescent devices were fabricated using these novel amines as the hole transporting layer and 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) as the electron transporting layer. Colour mixing or green emission was observed when tris(8-hydroxyquinoline)aluminium (Alq3) was used as the electron transporting layer. However insertion of a thin layer of TPBI or 1,3,5-tris(4-tert-butylphenyl-1,3,4-oxadiazolyl)benzene (TPOB) in between the HTL and Alq3 layers led to pure blue emission owing to the confinement of recombination inside the HTL layer containing the compounds.
一系列含有芘和六苯基苯树枝状结构的蓝光发射三芳胺通过采用Diels–Alder反应和钯催化的C–N偶联反应成功合成。它们在差示扫描量热法中显示出高玻璃转变温度(>140 °C),并且在循环伏安法中表现出简便的可逆氧化耦合。它们还具有热稳定性,分解温度超过385 °C。使用这些新型胺作为空穴传输层,1,3,5-三(N-苯基苯并咪唑-2-基)苯(TPBI)作为电子传输层,制备了高效的蓝光发射电致发光器件。使用三(8-羟基喹啉)铝(Alq3)作为电子传输层时,观察到颜色混合或绿色发射。然而,在HTL层和Alq3层之间插入一层薄的TPBI或1,3,5-三(4-叔丁基苯基-1,3,4-噁二唑基)苯(TPOB)导致了纯蓝光发射,这归因于在含有化合物的HTL层内的再组合限制。