電漿薄膜製程技術應用於綠色節能材料特性提昇之研究

Abstract

本計畫目標是要開發符合環保並且具經濟效益的銅銦鎵硒(CIGS)薄膜太陽能電池製程技術。擬開發無毒性的硒化製程以取代使用劇毒硒化氫蒸氣的傳統製程，並開發不含鎘溶液的化學法來製作緩衝層，以免除毒性廢液的疑慮。 本計畫共分為兩階段進行探討。第一階段是以CIGS硒化系統進行硒化製程，研究中將改變硒化溫度以及硒化時間，探討此兩種變因的改變對CIGS薄膜吸收層微結構與光電特性的影響。第二階段則是以化學水浴沉積法成長硫化鋅薄膜，在此製程參數設計方面，主要藉由改變氨水濃度與沉積時間來確定出其製程的最佳條件，並利用場發射掃描式電子顯微鏡、X光繞射儀與紫外光/可見光光譜儀等對硫化鋅膜層進行成分與穿透率分析。CIGS 元件的製備將以濺鍍沉積搭配無毒性的硒化法，並配合即時多階段溫度熱處理技術進行CIGS吸收層退火結晶製程。同時將利用既有的奈米氧化物製備與靶材製作技術，開發符合薄膜太陽能電池所用的透明導電氧化物薄膜，以能提高太陽能電池的光電轉換效率。

This project is to develop a novel and environmental friendly process for the fabrication of copper indium gallium diselenide (CIGS) thin-film solar cells with high conversion efficiency. We will develop a non-toxic selenization method to replace conventional process utilizing the extremely toxic H2Se vapor. Also, the deposition of buffer layer within the cadmium (Cd)-free chemical solutions will be proposed. It will be divided into two stages in this proposal. In the first stage, it is for the CIGS selenization process. The effects of selenization temperature and time on the CIGS thin films will be studied by XRD analysis method to indentify the change in the CIGS film after all types of selenization processes. In the second stage, the thin buffer layer of zinc sulfide will be deposited by the chemical-bath-deposition technique. An optimization deposition condition will be obtained by changing ammonium concentration and deposition times. Material analysis techniques including SEM, XRD and ultraviolet-visible spectrometer also will be used to analyze the compositions and transmittance of ZnS thin film. The solar cell devices will be prepared by sputtering process incorporated with the new selenization method in which the CIGS light-absorbed layer will be recrystallized by an in-situ multi-step heat treatment during thin-film deposition. Based on the present resources and previous experience in the preparation of nono oxide powers and sputter targets, a transparent conductive oxides (TCO) electrode suitable for the CIGS solar cell process can be successfully achieved.