電化學沉積氧化鋅奈米結構應用於染料敏化太陽能電池之研究

Electrochemical deposition of Zinc Oxide Nanostructures and their application for Dye-sensitized Solar Cells

張家彬(Chia-Being Chang)

指導教授 ： 余碗琴

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2014年)

摘要

本研究以二階段電化學沉積法於低溫下製備階層式氧化鋅奈米結構，並將其製備成染料敏化太陽能電池的工作電極。二階段電沉積過程包含先將氧化鋅奈米片沉積於導電玻璃基板上，再於奈米片上沉積奈米顆粒。探討的主要變因是第一階段電沉積的鍍液溫度(50-70°C)與時間，以及第二階段電沉積的ZnCl2濃度與沉積時間。研究結果顯示，第一階段電化學沉積溫度會影響奈米片中氧化鋅前驅物Zn5(OH)8Cl2之比例，低溫較高溫容易形成Zn5(OH)8Cl2，經熱處理後，該前驅物會轉變成氧化鋅，並於奈米片上形成微小孔洞，奈米片的孔隙度與鍍液溫度成反比。經過沉積條件的最適化，以此多孔性奈米片結構製成的D149染敏電池，效率最高可達3.56%。接著藉由第二階段電沉積形成奈米片/奈米顆粒複合結構，相較於單純的奈米片結構，此複合結構增加染料吸附量，並改善電池的光電流，電池光電轉換效率最高可達4.22%。

關鍵字

染料敏化太陽能電池 ； 氧化鋅 ； 電化學沉積 ； 低溫製備 ； 階層式奈米結構

並列摘要

A two-stage electrochemical deposition process was employed to prepare hierarchical ZnO nanostructures consisting of nanosheets and nanoparticles. The two-stage process involves the growth of primary nanosheets on conductive glass substrates, followed by the growth of nanoparticles on the surfaces of the primary nanosheets. The ZnO nanosheet/nanoparticle composite architecture was loaded with the organic dye D149 and explored as the photoanode of dye-sensitized solar cells (DSSCs). The correlations between the electrodeposition conditions and the properties of the deposited nanostrucutres, as well as the photovoltaic performance of the resulting DSSCs were investigated. The main electrodeposition parameters examined in the present study included the first-stage deposition temperature and time, and the ZnCl2 concentration and deposition time in the second stage. The first-stage deposition temperature, varied from 50°C to 70°C, had a significant impact on the chemical composition of nanosheets; the lower the temperature, the higher the content of Zn5(OH)8Cl2, which is a precursor of ZnO and can be converted into ZnO through a mild heat treatment. The pyrolysis of Zn5(OH)8Cl2 not only produced ZnO, but also generated numerous through pores on the nanosheets. The number of through pores and thus the porosity of the nanosheet could be tuned by varying the first-stage deposition temperature. Through optimization of electrodepostion condition, DSSCs based on the nanosheets alone attained an overall conversion efficiency of 3.56%, whereas those constructed from the composite nanostructures achieved an overall conversion efficiency of 4.22%, an improvement resulted from a significant increase in dye loading and short-circuit current density.

並列關鍵字

dye-sensitized solar cells ； ZnO ； electrochemical deposition ； low temperature preparation ； hierarchical nanostructure

參考文獻

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