本研究利用溶液製程製備非晶矽奈米線，以及合成硫化鉍奈米粒子 (Bi2S3 NPs)，來製備一種由零維奈米粒子與一維矽奈米線所組成的新型複合奈米結構 (hybrid nanostructure)。此結構利用一維奈米線提供大的有效面積及低反射率，與零維硫化鉍奈米粒子進一步幫助吸光，達到提升太陽能電池效率的目標。
　　本研究嘗試調整不同銀催化劑沉積溶液濃度以及沉積時間，製備出以濕式化學蝕刻法形成之非晶矽奈米線，此蝕刻法不需使用真空系統，也不需另外定義催化劑沉積位置，為一快速、簡單且適合大面積製作之方法。此外，本研究亦透過不同反應溶液濃度、基板表面處理、反應溫度以及添加分散劑與否等因素之調變，將硫化鉍奈米粒子自組裝於非晶矽奈米線。最後，分別以非晶矽以及單晶矽為基板，利用此複合奈米結構做為吸收層，製作太陽能電池。
　　分析本研究製備之吸收層的光學特性，在奈米線部分，所有量測波段 (400 -1300 nm) 的吸收率皆較原本之薄膜基板有顯著提升；將硫化鉍奈米粒子合成於奈米線上形成Bi2S3 NPs / a-Si:H NWs與Bi2S3 NPs / c-Si NWs複合奈米結構後，吸收率進一步上升，且在長波長範圍內明顯增加，顯示硫化鉍奈米粒子為一相當具有潛力的光吸收媒介 (light harvesting agent)，能有效幫助吸光，達到預期之太陽光光譜全波段吸收之目的。
　　在本研究中以此複合奈米結構組成太陽能電池，顯示此結構應用於單晶矽以及非晶矽電池之吸收層的可能性；以硫化鉍奈米粒子自組裝於單晶矽奈米線組成之電池，電性表現為Voc = 0.421 V、Jsc = 9.196 mA/cm2、FF = 20.7 %、η = 0.802 %，其中短路電流密度較僅由單晶矽奈米線組成之太陽能電池有顯著提升 (由1.163 mA/cm2提升為9.196 mA/cm2)，能量轉換效率由0.044 % 增加至0.802 %。由上述結果得知，此複合奈米結構具有進一步提升太陽能電池之效率的可能性。

A hybrid nanostructure with self-assembled 0-D Bi2S3 nanoparticles on 1-D a-Si:H nanowires was developed as a new absorption material in this work. It has been demonstrated the feasibility of using a metal-induced chemical etching process, which is simple, rapid, low-temperature and suitable for large-area production, to fabricate a-Si:H nanowires. The Bi2S3 NPs were self-assembled on the a-Si:H NWs as well as c-Si NWs to test the feasibility for photovoltaic applications.
The UV-Vis results showed that the absorption of a-Si:H nanowires was greatly enhanced attributed to superior antireflection properties over a large range of wavelengths. Bi2S3 NPs were successfully synthesized on the surface of as-prepared a-Si:H nanowires and characterized, showing that it could serve as an efficient light harvesting agent. The combination of Bi2S3 NPs and a-Si:H NWs as well as Bi2S3 NPs and c-Si NWs provided the possibility to realize the desired wide-band spectrum of sunlight absorption.
As this hybrid system was applied to a-Si:H and c-Si, the superior antireflection properties of NWs along with the integration of Bi2S3 NPs as light harvesting agents yielded a substantial enhancement in the optical absorption. For the solar cell based on Bi2S3 NPs / c-Si NWs, the result showed substantial enhancement in the short-circuit current density and power conversion efficiency compared to that of the solar cell based on only c-Si NWs (Jsc = 1.163 mA/cm2, PCE = 0.044 % for c-Si NWs and Jsc = 9.196 mA/cm2, PCE = 0.802 % for Bi2S3-NPs / c-Si NWs). Thus, the hybrid nanostructures presented in this study provided the feasibility for their future photovoltaic applications.

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