Synthesis and Electroluminescence Properties of Novel Fluorine-based Copolymers Containing Electron-Donor and Acceptor Moieties

• Main Authors: Li-Ga Hsieh, 謝澧佳
• Other Authors: Kun-Li Wang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/3q2ccy

碩士 === 國立臺北科技大學 === 化學工程研究所 === 96 === Polyfluorene is a well known hole-transporting material with high mobility. Attempts have been made to improve the electron-transport and hole-transport properties of polyfluorenes by introducing electron-donor and electron-acceptor moieties, respectively. In part A, we synthesized two fluorene-based copolymers through the incorporation of electron donor triphenylamine and electron acceptor 1,2,4-triazole moieties group into the polymer backbone. The PTPATAZ-F8 and PTAZTPA-F8 copolymers exhibited good thermal stability with 5％ loss weight temperature of 403℃ and 411℃, and the glass transition temperatures of 135℃ and 185℃, respectively. The emission maxima of copolymer films on the photoluminescence spectra were 413-435 nm, which corresponded to blue color. From electrochemical results, PTPATAZ-F8 containing triphenylamine main chain showed high ionization potential（HOMO=-5.31） than PTAZTPA-F8（HOMO=-5.72）. Electroluminescence device with the configuration of ITO/PEDOT：PSS/ PTPATAZ-F8/LiF/Al was fabricated to evaluate the potential EL application. The device using PTPATAZ-F8 as the active layer showed EL performance with max emission band at 444nm and turn-on voltage at 6V. The maximum luminance was 84 cd/m2 and the maximum luminance efficiency was 0.044 cd/A. The CIE’ 1937 coordinate was located at（0.160, 0.130）. In part B, we used the monomers in port A through the incorporation electron acceptor 2,1,3-benzothiadiazole into the polymer backbones. The PTPATAZBT-F8 and PTAZTPABT-F8 copolymers exhibited good thermal stability with 5％ loss weight temperatures of 433℃ and 406℃, and the glass transition temperatures of 155℃ and 153℃, respectively. The emission maxima of copolymer films on the photoluminescence spectra were 541-547 nm, which corresponded to yellow-green color. From electrochemical results, the HOMO level of PTPATAZBT-F8 and PTAZTPABT-F8 showed the same as part A. The device using PTPATAZBT-F8 as the active layer showed best EL performance with max emission band at 542nm and turn-on voltage at 5V. The maximum luminance was 696 cd/m2 and the maximum luminance efficiency was 2.02cd/A. The CIE’ 1937 coordinate was located at（0.345, 0.625）.