Theoretical Study of Fluorene’s Derivatives and Their Polymers

• Main Authors: Huan-Sheng Yan, 顏煥昇
• Other Authors: 王伯昌
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/82150133569523804098

碩士 === 淡江大學 === 化學學系碩士班 === 95 === Polyfluorene is a high π-electron conjugated polymer. It can be applied for the organic semi-conductor material, OLED, PLED, and OFET. Electron-drawing groups and electron-withdrawing groups can affect the Egap of polythiophene.In this study, the geometrical structures and electronic properties of polyfluorene is studied using two methods. One, we use DFT method with periodic boundary condition (PBC) to calculate HOMO energies, LUMO energies and the HOMO-LUMO gaps of the polymers. The other, HOMO energies, LUMO energies and the HOMO-LUMO gaps of the oligomers of the polymers are studied by the density functional theory with B3LYP functional. The lowest excitation energies (Egs) and the maximal absorption wavelength λabs of the oligomers of these polymers are studied employing the time-dependent density function theory (TDDFT) and semiempirical method Zindo. According to my calculating result, the Egap has the same tendency with the experimental value. This study provide a simple and satisfying method, which may be applied to design new materials.