傳統CIGS薄膜太陽能電池使用CdS緩衝層，以ZnS為緩衝層材料取代CdS可避免環境汙染，並探討ZnS緩衝層與CIGS薄膜太陽能電池之研究。故本論文討論ZnS緩衝層利用退火方式，使Zn原子擴散進入CIGS吸收層表面，以形成CIGS同質pn接面，因同質pn接面製作之薄膜太陽能電池可減少接面載子復合及提高電池效率。
首先，將清洗過的ITO基板上濺鍍銅銦鎵（CuInGa）先驅物，並以兩階段硒化溫度法完成p型CIGS吸收層，接著利用化學水浴法成長ZnS緩衝層，經過真空退火使Zn擴散進入CIGS吸收層，使其表面轉換為n型CIGS，藉此形成同質結構之pn接面，然後分析其接面特性及擴散情形；其中，變化參數為ZnS退火溫度與時間。
硒化完成後之CIGS薄膜以SEM觀察其表面型態、以EDS分析材料比例、以GIXRD判定化合物材料、以α-step來分析厚度、以四點探針測量片電阻、以熱探針判定半導體pn導電型式，並以I-V量測觀察其pn接面特性。最後， ZnS/p-CIGS薄膜以300oC，20分鐘退火可成功的形成CIGS同質pn接面。

Because of Cd is a highly toxic material, ZnS thin film has been proposed as the buffer layer for CIGS solar cell to replace CdS for addressing its environmental concerns. In this thesis, ZnS deposited on CuIn1-xGaxSe2（CIGS）thin film followed by vacuum annealing is studied. Zn diffusion into the p-type CIGS layer to form a thin n-type CIGS layer, and therefore CIGS p-n homojunction, was investigated. Solar cells fabricated with a homojunction will have a lower recombination rate at the junction and therefore better conversion efficiency.
First, CuInGa precursors were co-sputtering deposited on a cleaned ITO substrate followed by a two-step selenization to form a p-type CIGS film. A ZnS film was then deposited onto the p-type CIGS film by chemical bath deposition technique. Through various vacuum annealing conditions, whether the diffusion of Zn into the skin layer of the p-type CIGS film can transform to an n-type CIGS film was investigated.
Surface of the CIGS thin film was observed by scanning electron microscope, composition of the film was analyzed by X-ray energy dispersive spectroscopy, and grazing incidence X-ray diffraction was used for phase identification of the films, film’s thickness was measured by a α-step film profilometer, sheet resistance of the film was measured by a four-point probe, a hot-probe technique was used to identify film’s conduction polarity, and I-V measurements were used to analyze the characteristics of the junction after the Zn diffusion. A CIGS homojunction has been successfully formed by annealing ZnS/CIGS films with 300 oC at duration of 20 minutes.

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