寬能隙半導體奈米材料之合成及其應用於染料敏化太陽能電池

Synthesis of Wide Bandgap Semiconducting Nanomaterials and their Applications for Dye-sensitized Solar Cells

何恕德(Shu-Te Ho)

指導教授 ： 林鶴南

國立清華大學/工學院/材料科學工程學系/博士(2009年)

https://doi.org/10.6843/NTHU.2009.00428

摘要

在我的論文研究中，合成了兩種重要的寬能隙半導性奈米材料：氧化鋅奈米線與銳鈦礦的氧化鈦奈米顆粒，前者是使用無催化劑的熱蒸鍍法，後者為水熱法，其奈米晶體藉由穿透式電子顯微鏡與X光繞射儀進行鑑定。氧化鋅奈米線的成長機制：表面粗糙度輔助氣-固相在此論文中被提出與討論，而且發現奈米線直徑與基板粗糙度的相關性，並且基於此成長機制，達成無催化劑下的氧化鋅奈米線高溫選區成長。
分別應用氧化鋅奈米線與氧化鈦奈米顆粒在染料敏化太陽能電池的光陽極材料中，結合高溫製成的氧化鋅奈米線，因具有絕佳的結晶性，藉此提升電子傳輸效率，使得電池轉換效率與填充因子分別達到為1.33%與0.52。利用銳鈦礦結構的氧化鈦奈米顆粒所製成的太陽能電池達到轉換效率與填充因子分別為8.86%與0.71，使用電化學阻抗分析儀量測氧化鈦電池的載子傳輸與再結合特性，並計算得到氧化鈦光陽極在照光開路下的電阻率。

關鍵字

寬能隙 ； 奈米材料 ； 染料敏化太陽能電池 ； 氧化鋅 ； 二氧化鈦

並列摘要

We have conducted the synthesis of 2 wide bandgap semiconducting nanomaterials: single crystalline ZnO nanowires and pure-anatase TiO2 nanoparticles by using catalyst-free thermal evaporation and hydrothermal methods, respectively. The surface-roughness-assisted vapor-solid growth mechanism of ZnO nanowires has been discussed in which the roughness-dependence of nanowire diameter is discovered and the selective-area growth of ZnO nanowire array can be achieved successfully based on this above mechanism without using either catalysts or seedlayers. Transmission electron microscope and x-ray diffraction have been used to characterize both of nanomaterials.
ZnO nanowires and TiO2 nanoparticles have been applied for photoanode materials in dye-sensitized solar cell. Dye-sensitized solar cells with ZnO nanowires and TiO2 nanoparticles have been fabricated with conversion efficiencies of 1.33% and 8.86% and fill factors of 0.52 and 0.71, respectively. The efficiency 1.33% of the former is improved due to the use of high crystalline ZnO nanowires. Electrochemical impedance spectroscopy has been also used to analyze properties of charge transport and recombination of the latter. The resistivity of TiO2 photoanode under illumination is obtained.

並列關鍵字

wide bandgap ； nanomaterial ； dye-sensitized solar cell ； zinc oxide ； titanium dioxide

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