砷化鎵是一種高效率的太陽電池材料，但是價格十分昂貴，因此如何降低其成本一直是一個重要的議題，所以在本實驗中將核殼結構之砷化鎵奈米線以鎵自催化方式成長於矽基板上，取代傳統生長於砷化鎵基板上，進而降低元件生產成本。
在論文中的第一部分，藉由電子束微影，在氧化層上形成週期孔洞陣列。藉由改變曝光電子劑量(μC cm-2)，控制氧化層孔洞直徑大小，並且控制電子束照射間距，得到不同密度氧化層孔洞。這一部分藉由控制孔洞直徑與密度，來探討孔洞直徑與孔洞密度對奈米線的影響。
在論文的第二部份為製作太陽能電池元件，由於電子束微影的範圍太小，產生的光電流太小，以至於量不到，所以只用原生氧化層的孔洞來代替電子束微影形成的孔洞。PEDOT:PSS是目前最有潛力的有機半導體材料之一，以PEDOT:PSS作為P型半導體材料，在氧化銦錫導電玻璃上旋轉塗佈一層薄膜，再將奈米線與導電玻璃結合，形成砷化鎵/PEDOT:PSS混合型太陽能電池元件，並對不同直徑、長度的奈米線及PEDOT:PSS旋轉塗佈速度進行轉換效率的探討。本研究中得到的最高效率為0.136%。

Gallium arsenide is a high-performance while expensive photovoltaic material. How to reduce the cost remains the major issue for GaAs-based photovoltaic. In this study, the Ga-assisted VLS growth technique was applied to the fabrication of GaAs nanowires based solar cells on Si substrates, which can reduce the cost.
In the first part of this thesis, we used electron-beam lithography to form periodic pinhole arrays in the oxide layer. We found that the beam dose (μC cm-2) determined the pinhole diameter, while the pitch controlled the pinhole density. Thereafter, we studied the influences of pinhole diameter and density on the morphology of GaAs nanowires.
In the second part, we fabricated the solar cell devices based on PEDOT:PSS and GaAs nanowire arrays. The PEDOT:PSS has been one of the most promising conducting polymers and can act as a p-type semiconductor material. The PEDOT:PSS thin film was first deposited onto the indium tin oxide (ITO) conductive glass by spin coating. Then, the GaAs nanowire arrays were put onto the conductive glass to fabricate the GaAs/PEDOT:PSS hybrid solar cell device. The effects of the nanowire length and diameter as well as the spin coating speed on the performance of hybrid devices were investigated. The best power conversion efficiency achieved in this work is 0.136%.

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