染料敏化太陽能電池反電極之研究開發

The Research and Development of the Counter Electrode in Dye-sensitized Solar Cells

王馨珮(Hsin-Pei Wang)

指導教授 ： 王錫福

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00613

摘要

本論文主要是以類鑽碳薄膜取代白金薄膜為染料敏化太陽能電池之催化層，並以掃描式電子顯微鏡觀察催化層之表面與截面、四點探針量測反電極之表面電阻率及循環伏安法觀察催化層對I-/I3-的催化特性，期望能提升太陽能電池元件之光電轉換效率與降低電池的製作成本。
研究中，提出四組反電極參數取代白金反電極(ITO/Pt)，分別為改變ITO/Pt/DLC(n-type)結構中DLC鍍膜時氮氣摻雜量、改變ITO/Cr/DLC結構中DLC的鍍膜時間、改變ITO/Cr/DLC(n-type)/Pt結構中Pt的鍍膜時間，及ITO/Cr/DLC(n-type)/Pt結構中以玻璃基板取代ITO玻璃基板。
研究中做為標準之反電極為ITO/Pt，其電池光電轉換效率約為3 %。而在ITO/Pt/DLC(n-type)結構中，鍍上DLC(n-type)層時氮氣摻雜量為10 sccm時之電池效率較無摻雜氮氣的電池高，且電極表面電阻率較低，光電轉換效率約為1.8 %。在ITO/Cr/DLC結構中，當DLC鍍膜時間為10.5分鐘時，其光電轉換效率約為1.5 %。在ITO/Cr/DLC(n-type)/Pt結構中，改變Pt層之鍍膜時間為10秒時，其電池效率可達3.3 %。在ITO/Cr/DLC(n-type)/Pt結構中以玻璃基板取代ITO玻璃基板後，其電池之光電效率亦可達3.2 %，表示可用玻璃基板取代ITO玻璃基板。CV檢測結果中，反電極ITO/Cr/DLC(n-type)/Pt及Glass/Cr/DLC(n-type)/Pt催化特性較ITO/Cr/DLC與ITO/Pt/DLC(n-type)優良，但與ITO/Pt差異不大，因Pt直接接觸電解液則能幫助氧化的電解液I3-還原成I-，DLC催化特性與導電性相對的皆較差。

關鍵字

染料敏化太陽能電池 ； 反電極 ； 催化特性 ； 光電轉換效率

並列摘要

This research is mainly concerned with replacement of platinum used as a catalyst layer of dye-sensitized solar cells with diamond like carbon (DLC). The DLC films were grown on indium-tin-oxide coated glass substrates by using cathodic arc deposition. Surface and cross-section layers of this catalyst were observed with scanning electron microscope; sheet resistance of the catalyst layer was measured by a four-point probe. The characteristic redox catalysis of I-/I3- is observed and assessed with cyclic voltammetry (CV). We expect to improve the photoelectric conversion efficiency and reduce the cost of the solar cells by using DLC. The performance of photoelectrochemical response by using DLC as counter electrode was also evaluated in this study.
New procedures for the growth of different films are presented in this study. The deposition parameters for counter electrodes are changed and four different counter electrodes namely, ITO/Pt/DLC(n-type), ITO/Cr/DLC, ITO/Cr/DLC(n-type)/Pt, and Glass/Cr/DLC(n-type)/Pt from ITO/Pt are prepared.
First, the counter electrode, which consists of ITO/Pt yields low resistance and the efficiency is about 3%. For the ITO/Pt/DLC(n-type), when different N2 concentrations (0, 5, 10, 30, 60 sccm) are doped, the results with N2 of 10 sccm, gave the best conversion efficiency of about 1.8%. Second, the counter electrode, which consists of ITO/Cr/DLC, and DLC is deposited on top of Cr (DLC deposition time is 5, 10.5, 12 mins), the cell efficiency is 1.5%. Third, the counter electrode, which consists of ITO/Cr/DLC (n-type)/Pt (Pt deposition time is 5, 10 seconds), exhibited an efficiency of 3.3%. After replacing ITO glass substrate with simple glass substrate, i.e Glass/Cr/DLC (n-type)/Pt structure, the photoelectric efficiency could reach to 3.2%, indicating that we can successfully replace ITO glass substrate with simple glass plate. CV measurements which are characteristic of catalysis for electrodes ITO/Cr/DLC/Pt and Glass/Cr/DLC(n-type)/Pt gave similar results like ITO/Pt, but they are better than ITO/Cr/DLC and ITO/Pt/DLC. The conduction bands and valance bands of films determined for Glass/Cr/DLC(n-type)/Pt are correlated with ITO/Pt. It can change I3- to I- because of the Pt layer directly in contact with electrolyte, but the catalysis characteristics and electric conductivity of DLC are relatively low.

並列關鍵字

dye sensitized solar cell ； counter electrode ； catalysis ； light to electron conversion efficiency

參考文獻

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