單層MoS2是一極具光電發展潛力的二維材料，本質為n型半導體，且其能隙屬於直接能隙，光電轉換效率高，同時表面無未鍵結懸鍵，可與其他材料形成良好異質接面。將單層MoS2與塊材基板結合製作光伏元件，可以進一步增加元件的吸光區域，大幅提升其總體吸光量。
本研究先以化學合成法 (CVD) 成長單層MoS¬2，再利用轉移的方式分別與p-type Si (100) 基板及p-type GaAs (100) 基板結合，形成異質p-n接面太陽能電池。首先，p-Si/MoS2太陽能電池部分，找出具有最高光電轉換效率的p-Si基板摻雜濃度，再以此為基準，進一步嘗試不同的上電極材料。此部分，p-Si/MoS2太陽能電池光電轉換效率最高達3.362 %。接著，p-GaAs/MoS2太陽能電池部分，是以超高真空分子束磊晶技術 (MBE) 在高摻雜濃度p-GaAs基板上磊晶成長不同摻雜濃度的GaAs薄膜，再藉由調變薄膜厚度以及多層結構之元件，找出具有最高光電轉換效率之元件結構。最終製備的p-GaAs/MoS2太陽能電池光電轉換效率最高達0.406 %。

Monolayer molybdenum disulfide (MoS2), as a two-dimensional material, is an n-type semiconductor with direct band gap suitable for optoelectronic applications. Moreover, the surface of monolayer MoS2 contains no nonbonding dangling bonds; therefore, it can form van der Waals heterojunctions with other semiconductor materials. Integration of monolayer MoS2 and bulk semiconductor materials can enhance the total absorption in photovoltaic devices.
In this work, monolayer MoS2 fabricated by CVD method were transferred on either p-type Si(100) substrates or p-type epitaxial GaAs films to form heterojunction p-n solar cells. In p-Si/MoS2 solar cells, we first investigated the most appropriate doping concentrations of Si substrates to yield heterojunction solar cells with the best power conversion efficiency. Then, different top electrode materials were studied in order to decrease the series resistance of the cells. The best power conversion efficiency obtained in p-Si/MoS2 solar cells was 3.362 %. In p-GaAs/MoS2 solar cells, a variety of GaAs thin films with different doping concentrations were grown on highly p-doped GaAs(100) substrates by MBE. The thickness of the film was optimized, and multilayer structures were attempted to find out the highest efficiency. The best power conversion efficiency in p-GaAs/MoS2 solar cells was 0.406 %.

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