二氧化鈦奈米晶體表面改質與內部掺雜在有機無機混成太陽能電池之應用

Interfacial nanostructuring and impurity doping of TiO2 nanocrystals on the application of organic/inorganic hybrid bulkheterojunction solar cell

朱叢鴻(Tsung-Hung Chu)

指導教授 ： 陳俊維

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02643

摘要

有機無機混掺太陽能電池在過去幾年來已積極的被研究與發展，具有製程低溫且、可彎曲、低成本、大面積、製造簡單…等優點。在本研究中我們藉著對無機材料進行表面改質及內部掺雜的方式來提升元件的能量轉換效率。本論文分為兩大部份: 第一部份將討論二氧化鈦奈米棒表面改質的技術，並且將其應用於導電高分子聚己基噻吩與二氧化鈦的混掺太陽能電池之中，第二部份則是在二氧化鈦奈米粒子之中掺入氟原子並研究其對混掺太陽能電池所產生的效應。
在表面置換的部份中，我們先以非水解的方法合成出比常見的二氧化鈦奈米棒更適合作表面處理的二氧化鈦奈米棒，接著再成功的將特定的界面活性劑吸附到其表面。根據界面活性劑的種類和添加量，我們採用一系列的實驗來對其進行定性和定量的分析。此外表面改質過的二氧化鈦和聚己基噻吩的混掺材料比未改質過的有更好的電荷分離效率以及較低的載子再結合率，最重要的是表面改質的技術使得元件效率有大幅的提升，而成為到目前為止在所發表關於聚己基噻吩與二氧化鈦混掺太陽能電池的文獻中表現最好的元件。
在雜質掺雜的部份中，由於氟原子掺雜對二氧化鈦有許多在電性上的益處，所以我們選擇氟原子來作為本研究中合適的掺雜物。我們以非水解合成法來合成出新穎的氟原子掺雜之二氧化鈦奈米粒子，並且發現其與聚己基噻吩混掺後具有較高的載子濃度、導電度、較優良的電荷分離效率、此外最重要的是在元件的表現上可以進一步的提升。

關鍵字

二氧化鈦 ； 表面 ； 太陽能電池 ； 高分子 ； 雜質掺雜 ； 奈米

並列摘要

Organic/inorganic hybrid solar sells have been energetically developed and studied in recent years. There are a number of advantages of it, such as processing with low temperature, flexible, low-cost, large area production and easy to fabricate. In this research, the improvement of power conversion efficiency will be realized by using technology of interface modification and impurity doping within the inorganic semiconductor materials. This essay has been divided into two parts: the first part is surface modification of TiO2 nanorods and its application in P3HT/TiO2 hybrid photovoltaic device, the second part is doping of TiO2 nanoparticles with fluorine atoms and its effect on P3HT/TiO2 hybrid solar cell.
For the project of surface modification, TiO2 nanorods with better surface processability than the conventional TiO2 nanorods have been synthesized by nonhydrolysis method, and the newly introduced ligands have been successfully attached to their surface. Qualification and quantification of the adsorbed ligands have been fulfilled by a variety of experiments, depending on the amount or type of the newly introduced ligands. The surface-modified TiO2/P3HT hybrid materials have better charge transfer efficiency and lower carrier recombination rate compared with the unmodified one. Most important of all, the efficiency of the as-fabricated TiO2/P3HT hybrid solar cell has been shown significant improvement after the surface modification process of TiO2 nanorods, which is by far the highest efficiency of all the reported TiO2/P3HT hybrid solar cells.
For the project of impurity doping, fluorine atom has been chosen as the suitable dopant, judging by its numerous beneficial effects on the electrical properties of TiO2. The newly synthesized fluorine-doped TiO2 nanoparticles has been demonstrated by a non-hydrolytic sol-gel approach and proven to be a suitable substitute for the TiO2 nanocrystals in the P3HT/TiO2 hybrid materials owing to their higher carrier concentration, better carrier conductivity, improved charge separation efficiency, and most importantly, the better performance of the as fabricated hybrid solar cell.

並列關鍵字

TiO2 ； surface ； doping ； solar cell ； polymer ； ligand ； impurity ； nano ； charge transfer ； charge transport ； efficiency

參考文獻

[5] N. Todorova, T. Giannakopoulou, G. Romanos, T. Vaimakis, Jiaguo Yu, and C. Trapalis: Preparation of Fluorine-Doped TiO2 Photocatalysts with Controlled Crystalline Structure. International Journal of Photoenergy., 2008, Article ID 534038 (2008)

Chapter 1

[1] John Perlin: The silicon solar cell turns 50.

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[3] Robert Plass: Nanoparticle sensitization of solid-state nanocrystalline solar cell. doctoral dissertation, 2004