銅銦鎵硒（CIGS）太陽能電池近年來廣受全球注目。是一種高轉換效率的薄膜太陽能電池，其實驗室轉換效率高達23.35%，在性能上遠超矽晶太陽能電池。諾貝爾物理獎得主H. Kroemer在1957年的論文中首次提出了異質結能帶偏移理論，他的名言“介面即是器件”道出了界面效應在許多半導體器件中的核心地位。 本研究以第一性原理模擬計算為基礎，利用VASP軟體和Material Studio計算材料的性質，建立了銀銅銦鎵硒硫（Ag-Cu-In-Ga-Se-S）六元化合物的能隙關係模型。並且進一步探討了該材料與硫化鎘（CdS）緩衝層之間的能隙偏移，分析不同成分對異質結能帶偏移的影響。這些研究結果將有助於提高CIGS太陽能電池的轉換效率，並為設計更高效的光伏器件提供理論基礎。

Copper indium gallium selenide solar cells have gained significant global attention in recent years. They are a type of thin-film solar cell with high conversion efficiency, achieving a laboratory efficiency of up to 23.35%, significantly outperforming silicon solar cells. Nobel Prize-winning physicist H. Kroemer first proposed the theory of heterojunction band offset in his 1957 paper, encapsulating the critical role of interface effects in many semiconductor devices with his famous saying, "The interface is the device." This study is based on first-principles simulation calculations, utilizing VASP software and Material Studio to calculate material properties. We established a bandgap relationship model for the six-element compound Ag-Cu-In-Ga-Se-S. Furthermore, we investigated the bandgap offset between this material and the cadmium sulfide (CdS) buffer layer, analyzing the effects of different compositions on the heterojunction band offset. These research findings will help improve the conversion efficiency of CIGS solar cells and provide a theoretical foundation for designing more efficient photovoltaic devices.

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