以咔唑為主體的共軛聚合物其光電性質對有機太陽能電池的研究

Theoretical Studies of the Electronic and Optical properties of the Carbazole-Based Conjugated Polymers for Organic Solar Cell

侯朝竣(Chao-Jiun Hou)

指導教授 ： 王伯昌

淡江大學/理學院/化學學系碩士班/碩士(2009年)

https://doi.org/10.6846/TKU.2009.00872

摘要

近年來咔唑（carbazole）為主體的衍生物，已經在許多光電材料上被廣泛的應用，而其主要的吸收光譜接近於可見光光譜，對於應用在太陽能電池上有不錯的吸收係數，許多研究聚合物的科學家也將其應用於太陽能電池的材料中。
本論文主要以咔唑為主體，而設計出五種不同的共聚物，進而探討其電子結構與光學性質，一開始先用DFT/B3LYP搭配6-31G*的基底函數計算單體數為n=1~4時結構的最佳化，接著再將最佳化的結構以TD-DFT/B3LYP/6-31G*與ZINDO方法求得其EHOMO、ELUMO與Eg，會得到三種不同的能隙值Eg（DFT）、Eg（TD）和Eg（ZINDO），當單體數增加時，Eg（DFT）、Eg（TD）和Eg（ZINDO）的能隙值都會逐漸降低，接著再將n=1~4的能隙值作出線性關係，經由外插法求得共聚物的能隙，進一步得到共聚物的能隙值，再將三種不同的能隙值與實驗值比較，可得到Eg（TD）的能隙與實驗值趨勢吻合且較為接近，再將五種共聚物經TD-DFT/B3LYP/6-31G*所得吸收光譜結果，探討五種共聚物在第一激發態所吸收的波長，其中二種主要吸收波長到達紅光的波長，另三種則是已到達近紅外光的波長，之後再將寡聚物以HF/3-21G算出基態（S0）時的最佳化結構再由CIS/3-21求得激發態（S1）的最佳化結構，最後再以TD/B3LYP/3-21G算出放射光的波長，發現其中四種共聚物的主要放射波長都在可見光範圍，只有一種出現在紅外光的範圍，對於在有機發光材料可能也有不錯的應用。
本研究中也提供了一種太陽能電池材料的設計方法，也設計了三種可能的太陽能電池材料，對於未來應用在設計太陽電池的材料為一種好的建議。

關鍵字

有機太陽能電池 ； 咔唑 ； 能隙

並列摘要

Recently years, carbazole’s derivatives has been used in photoelectric material generally,and it’s absorption spectrum with solar spectral match. so using in solar cell material will have well absorption coefficient, several alternating polymeric structures have been investigated to carbazole’s derivatives for solar cell applications.
This thesis are design the carbazole-based conjugated polymers and uses theoretical and computational methods DFT/B3LYP and basis set 6-31G* to optimize the derivatives structure than uses the TD/B3LYP/6-31G* and ZINDO to calculated the energy level, so we will get three different energy gap value, Eg（DFT）、Eg（TD）and Eg（ZINDO）
, than we will get the oligomer n=1~4 energy gap value to find the linear equations, and use the extrapolation method to get the n=∞ energy gap, the Eg（TD）method is most close the experimental value. And we calculated the five oligomer with TD/B3LYP/3-21G to get absorption spectrum, and we will find three kind of oligomer have visible light absorption and two kind of oligomer have near IR absorption. Finally, we use HF/3-21G to calculate excited state structure and TD/B3LYP/3-21G to calculate emission spectrum, and the emission wavelength are between visible light range, so we can speculation the material may be a good photoelectric material.
This investigate to provide a good method to design the solar cell material and design three kind of material, For feature it’s will be a good direct to design solar cell material.

並列關鍵字

energy gap ； solar cell ； carbazole

參考文獻

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