【作者】 高文正；

【导师】 李祥高；

【作者基本信息】 天津大学 ， 应用化学， 2012， 博士

【摘要】 空穴传输材料（HTMs）是一类重要的有机光电功能材料，它能有效提高空穴在器件中的注入效率和传输效率。由于小分子空穴传输材料和聚合物空穴传输材料的应用性能各有优劣，寻求新型性能优良的空穴传输材料一直是该领域研究的热点。本文设计合成了13种以不同桥键链接的含三苯胺基团的新型空穴传输材料。利用IR、~1H NMR和HRMS对中间体和目标产物进行了结构表征。所合成化合物在常见溶剂（如四氢呋喃、氯仿、乙酸乙酯）中均有良好溶解性。量子化学计算发现，所合成空穴传输材料的立体构型，能有效抑制化合物的结晶，且所合成化合物的HOMO能级与常用阳极材料ITO功函相近，有利于空穴的注入。对所合成空穴传输材料进行了光物理性能，电化学性能和热性能测试。结果表明，HTM1-HTM13在四氢呋喃溶液中的有两个吸收峰，分别处于294nm~309nm和375nm~434nm之间；这些化合物发射光谱范围从蓝光到黄绿光，荧光发射峰处于426nm~519nm的范围内；荧光寿命位于1.60ns~3.13ns之间，绝对荧光量子效率在22.3%~68.1%之间。电化学测试表明，化合物HTM1-HTM13具有合适的HOMO能级(-5.08eV~-5.29eV)，有利于空穴由阳极向空穴传输层的注入。热性能测试表明，化合物HTM1-HTM13具有良好的热稳定性，玻璃化转变温度在72~146℃之间。用所合成化合物通过旋转涂覆工艺制备了薄膜，并对其进行了表征。通过X射线衍射研究了薄膜的结晶性，结果表明所形成有机薄膜为无定型结构；原子力显微镜照片显示了有机薄膜的表面平整度良好，并用场发射扫描电子显微镜观察薄膜表面形貌和测量薄膜厚度。结果表明，化合物分子量的增加和共轭程度的提高可以改善化合物的成膜性。将合成化合物通过真空蒸镀或旋转涂覆的工艺制备了有机电致发光器件(OLEDs)，结果显示随着化合物成膜性能的改善，空穴传输材料可以通过旋涂工艺成膜来制备有机电致发光器件。分子量较小的化合物(HTM5,7,8,11,13)采用真空蒸镀工艺，制备了ITO/HTL/Alq3/Al/LiF结构的器件，启亮电压在4.2V~9.8V之间，最大亮度可以达到8723cd/m~2。分子量较大的化合物(HTM1,2,3,4,6,9,10,12)采用旋转涂布工艺，制备了ITO/HTL/Alq3/Al/LiF结构的器件，结果显示化合物HTM10制备器件性能最优，启亮电压为5.2V，发光亮度为846.5cd/m~2，通过工艺改进制备了ITO/HTM10/P-PPV/Ba/Al结构的器件，结果显示启亮电压降到3.25V，发光亮度提高为103690cd/m~2。以化合物HTM12制备的ITO/HTM12/P-PPV/Ba/Al结构的器件，启亮电压为3.5V，发光亮度为70941cd/m~2，均优于以PEDOT为空穴传输层制备的相同结构OLED器件。更多还原

【Abstract】 The hole transport material is one of the most important organicelectroluminescent materials, which could improve the injection efficiency and thetransmission efficiency of the holes in the device effectively. Since the small moleculehole transport material and the polymer hole transport material have their ownadvantages and disadvantages, seeking novel hole transporting materials which haveexcellent performance has become a very important topic.In this thesis, thirteen novel luminescent hole-transporting materials (HTMs)containing triphenylamine groups connected with different bridged bonds weresynthesized via wittig reaction. All of the compounds were characterized by infraredspectrum (IR), proton nuclear magnetic resonance (1H NMR) and high resolutionmass spectrum (HRMS) technology. The compounds show excellent solubility incommon organic solvents such as tetrahydrofuran, chloroform, and so on.The quantum chemistry calculation was performed based on density functionaltheory (DFT). The calculation result illustrated that the geometry of the titledcompounds is benefit to inhibit the crystallization of the compounds effectively. Thehighest occupied molecular orbital (HOMO) all HTMs could match with the workfunction of ITO (-4.7eV), which are suitable to the hole injection. Optical,electrochemical and thermal properties also have been investigated. The UV-Visabsorption spectra of the thirteen compounds in dilute tetrahydrofuran were measured.The compounds exhibit two absorption bonds at the region of294nm~309nm and375nm~434nm, respectively. The maxima emission peaks are located at426nm~519nm, corresponding to blue to yellow light emission. These materials have thefluorescence life between1.60ns and3.13ns. And their fluorescence quantum yieldare from22.3%to68.1%in dilute tetrahydrofuran. Cyclic voltammetrymeasurement showed that HOMO levels of these compound are in the range of-5.08eV~-5.29eV, which are proper for hole injection. Thermal properties of thesynthesized compounds were studied by differential scanning calorimetry (DSC).These compounds possess higher Tgbetween72℃and146℃, suggesting that theyhave excellent thermal stability.The synthesized compounds were prepared to organic film by spin-coatingprocess, and the films were characterized. The crystallinity of the films were studied by X-ray diffracion(XRD), the result show that these films have amorphous structure.The organic film has a smooth surface, which could be supported by atomic forcemicroscopy (AFM) images and the field emision scanning electron microscope (SEM)photograph. All of these results show that the film formability of these compoundscould be improved by increasing of the compound molecular weight and theexpanding of the conjugate system. The titled compounds were employed to fabricateorganic electroluminescent light emitting devices (OLEDs) by process vacuumdeposition or spin-coating. The film could be prepared by spin-coating process,indicating good film formability of these compounds. Small molecular weightcompounds (HTM5,7,8,11,13) were used to fabricate OLEDs with the configurationof ITO/HTL/Alq3/Al/LiF through vacuum deposition way, and the turn on voltage ofthe devices are between4.2V and9.8V, the maximal luminancce efficiencies are8723cd/m~2obtained from the device fabricated with HTM5. Larger molecular weightcompounds (HTM1,2,3,4,6,9,10,12) were fabricated OLEDs with the configuration ofITO/HTL/Alq3/Al/LiF by spin-coating way, results show that the device preparedfrom HTM10has the best performance. Its turn on voltage is5.2V, and its maximalluminancce efficiencies is846.5cd/m~2. Then we improved the configuration of device.HTM10,12and PEDOT were used to fabricate OLEDs with the configuration ofITO/HTL/P-PPV/Ba/Al. The turn on voltage of device prepared from HTM10dropped to3.25V, and the maximal luminancce efficiencies rised to103690cd/m~2.The turn on voltage of device prepared from HTM12is3.5V, and the maximalluminancce efficiencies is70941cd/m~2, both of their performance are better than thedevice prepared from PEDOT.更多还原