芴聚合物為一擁有高共軛系統的結構，可應用於有機半導體元件、OLED、PLED等光電材料上。改變主鏈使其成為共聚物或利用不同的推、拉電子基取代其側鏈後，其能隙也會有所改變，進而發展出不同能隙的光電材料。 使用幾種量子力學計算方法如PBC-DFT、DFT、TDDFT和ZINDO四種，探討芴高分子聚合物的電子性質。經計算得到的值與實驗值相比較後，發現計算值與實驗值有相同的趨勢。其中以使用密度泛函數(PBC-DFT)之B3LYP/6-31G*層級來計算這些芴高分子聚合物的電子結構、以及相關之電子軌域能量( HOMO，LUMO )與ΔEgap( HOMO-LUMO )，計算出來的結果最好且最省時，因此將來對於類似聚合物的開發、設計上可以當做參考的工具。 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.
