为了探究激基复合物对于有机发光二极管(OLED)性能的影响, 本文制备了一系列基于无激基复合物结构和激基复合物结构的器件。首先对比分析N,N′-bis(naphthalene-1-yl)-N,N′-bis(phe-nyl)-benzidine (NPB)、4,4′,4″-tris(Ncarbazolyl)-triphenylamine (TCTA)、1,3,5-tris(Nphenylbenzimidazole-2-yl) benzene (TPBi)、NPB∶TPBi和TCTA∶TPBi五种薄膜的光致发光(PL)光谱, 确定了NPB∶TPBi不能有效地形成激基复合物, 而TCTA∶TPBi符合激基复合物的要求。随后结合蓝色磷光Bis[(3,5-difluoro-2-(2-pyridyl) phenyl-(2-carboxypyridyl) iridium(Ⅲ) (FIrpic)和橙色磷光Bis(4-phenylthieno[3,2-c]pyridinato-N,C2′) acetylacetonate iridium(Ⅲ) (PO-01)超薄发光层, 制备了一系列的单色和白色OLED器件, 并优化了磷光超薄发光层的厚度以获得更高亮度和效率。相比于无激基复合物器件, 基于激基复合物的单色蓝光、橙光、双色白光器件性能得到极大的提升, 获得最大的亮度分别为5 823, 29 000, 23 790 cd/m2, 最大功率效率(PE)分别为15.3, 47.8, 51.0 lm/W。这些改进的器件性能归因于三重态激子到单重态激子的反向系间窜越(RISC)和高效的主客体能量转移。

In order to explore the influence of exciplex on the performance of organic light-emitting diodes (OLED), a series of devices based on the structure with or without exciplex have been fabricated. Firstly, it is determined that NPB∶TPBi is not effective to form exciplex, while TCTA∶TPBi possesses exciplex performance requirements by comparing and analyzing the photoluminescence spectra of N,N′-bis(naphthalene-1-yl)-N,N′-bis(phe-nyl)-benzidine (NPB), 4,4′,4″-tris(Ncarbazolyl)-triphenylamine (TCTA), 1,3,5-tris(Nphenylbenzimidazole-2-yl) benzene (TPBi), NPB∶TPBi and TCTA∶TPBi films. Then, a series of monochromatic and white OLED devices have been fabricated by combining ultrathin emission layer of blue phosphorescence bis[(3,5-difluoro-2-(2-pyridyl) phenyl-(2-carboxypyridyl) iridium(Ⅲ) (FIrpic) and orange phosphorescence bis(4-phenylthieno[3,2-c]pyridinato-N,C2′) acetylacetonate iridium(Ⅲ) (PO-01), and the thickness of ultrathin phosphor layers are optimized to achieve high brightness and efficiency. Compared with devices without exciplex, the performance of monochromatic blue, orange and two-color white devices based on the exciplex have been greatly improved, with the maximum brightness of 5 823, 29 000, 23 790 cd/m2 and the maximum power efficiency (PE) of 15.3, 47.8, 51.0 lm/W, respectively. These improved device performances are attributed to the reverse inter system crossing (RISC) from triplet exciton to singlet exciton and the efficient host-guest energy transfer, which provides a feasible idea for the preparation of high-efficiency OLED devices with simple structure.