Synthesis and Physical Properties of Multi-(1,3,4-oxadiazo-2-yl)benzene and Biphenyl derivatives, and Their Application in Organic Electroluminescent Devices.

• Main Authors: Chih-Chiang Yang, 楊智強
• Other Authors: 梁文傑
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/87396094266981799691

博士 === 國立臺灣大學 === 化學研究所 === 97 === In this thesis, we synthesized multi-(1,3,4-oxadiazo-2-yl)benzene and biphenyl derivatives. The conformational and substitution effects were studied by photophysical properties and cyclic voltammetry. For the fluorescence and phosphorescence of 2,2’-(1,3,4-oxadiazo-2-yl)biphenyl(BOBP) showed good spectra matching with absorption spectra of MLCT1 and MLCT3 transition of Ir(ppy)3. While BOBP was used as host material for Ir(ppy)3 in PHOLED device, the maximum brightness of 43,000 cd/m2 with efficiency of 26 cd/A at 200 cd/m2 was achieved. The first-reduction potential of multi-(1,3,4-oxadiazo-2-yl)benzenes were affected by conformation and number of oxadiazole units. The emission color of a series devices could be tuned by doping different multi-(1,3,4-oxadiazo-2-yl)benzenes in hole-transporting polymer PVK. Two multi-(1,3,4-oxadiazo-2-yl)benzenes doped in PVK polymer matrix could lead emission band broadly, indicating that the two kinds of exciplexes might form in the OLED device at same time. The emission color were controlled by the efficiency of formed excited state complexes.