利用化學水浴法製備銅銦鎵硒太陽電池中硫化鋅緩衝層性質之研究

Study on properties of using chemical bath deposition to prepare Zn(O,S) buffer layer of CIGS thin film solar cell

謝宗儒(TSUNG-JU HSIEH)

指導教授 ： 劉宗平

元智大學/電機通訊學院/光電工程學系/碩士(2012年)

摘要

在太陽電池產業的發展中，銅銦鎵硒(CIGS)薄膜太陽電池是相當重要的一環。對於單一的CIGS太陽電池而言，其主要由P型的CIGS與N型的硫化鎘(CdS)所組成。因為鎘是一種有毒的環境污染物，考慮採用無鎘材料作為緩衝層是一件非常急迫的事。由於硫化鋅(Zn(O,S))具有直接且寬能隙的優點，可增加CIGS太陽電池在短波長範圍的光吸收。因此，Zn(O,S)逐漸成為取代CdS的有利材料之一。
在此研究中，採用化學水浴法(CBD)來製備Zn(O,S)薄膜。為了加快成膜速率，進而在生產過程中添加過氧化氫。選用過氧化氫濃度、成膜時間、成膜環境PH值及退火溫度作為參數，進行樣品退火研究，以期獲得製備Zn(O,S)薄膜的最佳參數。
經由XRD量測得知，Zn(O,S)薄膜具有閃鋅礦結構。在固定成膜時間下，當過氧化氫的濃度增加時，薄膜的繞射峰會趨於明顯。從SEM照片所呈現的表面形貌得知，如果過氧化氫濃度在控制之下，則可在長成膜時間下獲得較佳的薄膜表面。EDS數據分析元素間的比例顯示，倘若減少薄膜內的氧離子含量，那麼S/Zn的比值會增加，而且可以獲得品質較佳的薄膜。
利用PL量測得知，如果成膜時間為7 min，加入的過氧化氫3 ml，則薄膜PL峰值的相對強度最大。此時，薄膜表面的結構較為緻密，其薄膜品質較佳。由UV量測得知，在PH值為10.15的水溶液環境下成膜，薄膜的透射率87%是最大的，其能隙為3.81 eV。
總結而言，按照最佳參數所製備的Zn(O,S) 膜膜，可作為CIGS薄膜太陽電池的緩衝層之用。

關鍵字

硫化鋅 ； 緩衝層 ； 化學水浴法 ； 過氧化氫 ； 銅銦鎵硒太陽電池

並列摘要

In the development of the solar cell industry, copper indium gallium selenide (CIGS) thin film solar cell is very important. For a single CIGS solar cells, it is mainly composed by a P-type CIGS and a n-type cadmium sulfide (CdS). Because cadmium is a toxic environmental pollutants, it is very urgent to consider the use of cadmium-free material as a buffer layer. ZnS (Zn (O, S)) has the advantage of direct and wide band-gap, it can increase the light absorption of CIGS solar cells in the short wavelength range. Therefore, Zn (O, S) is becoming one of the favorable materials to replace CdS.
In this study, the use of chemical bath deposition (CBD) to prepare Zn (O, S) thin films. In order to speed up the rate of film formation, thus the hydrogen peroxide is added in the production process. The concentration of hydrogen peroxide, the time of film formation, the PH value of film-forming environment, and the annealing temperature were selected as parameters of sample annealing study in order to obtain the optimal parameters to prepare the film of Zn (O, S).
Through XRD measurements, the Zn (O, S) thin film has a structure of zinc blende. At a constant formation time, when the concentration of hydrogen peroxide increases, the diffraction peak of the films is becoming more apparent. From the surface morphology shown in the SEM photograph, if the concentration of hydrogen peroxide is under control, a better film surface can be obtained at a long formation time. The ratio between the elements analyzed by EDS data shows that if the content of oxygen ion within the film is decreased, then the ratio of S/Zn will be increased and a better quality of film can be obtained. PL measurements inform that if the film-forming time is 7 min and the added peroxide hydrogen is 3 ml, the relative intensity of PL peak of the film is the largest. At this point, the structure of the film surface is more compact and its film quality is much better. UV measurements reveal that if the film is formed in aqueous environment with pH value of 10.15, then the transmittance of 87% of the film is the maximum and its bandgap is 3.81 eV.
In summary, thin films of Zn(O, S) prepared in accordance with optimal parameters can be used as a buffer layer of CIGS thin-film solar cells.

並列關鍵字

Zn(O ； S) ； buffer layer ； chemical bath deposition ； hydrogen peroxide ； CIGS solar cells

參考文獻

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