近年來由於綠色能源相關議題備受關注，而摩擦電奈米發電機(TENG)作為一種新興的綠色能源，可利用環境周圍的機械能發電，通過兩材料的摩擦起電產生摩擦電荷，並經由感應電荷來進行發電。TENG具有高轉換效率、製作成本低、高穩定性、應用性高等優勢，使得TENG在能源技術中具有競爭力。在摩擦電材料的背景下，由於氧化鋅半導體特性和通過摻雜容易控制氧空缺和鋅間隙的本質缺陷，氧化鋅提供了一個很好的機會調整表面的總載子濃度以進行電荷轉移，因此本研究將透過摻雜鎵來改變氧化鋅薄膜材料的電性及表面功函數等，並探討摻雜鎵對於擦電輸出之影響。
在此研究中，首先通過磁控濺射生長氧化鋅薄膜，接著利用CVD在高溫下通入Ar氣流，將不同量的鎵金屬有機前驅物，帶到材料表面通過熱擴散將鎵摻雜進氧化鋅薄膜中，以製備出不同濃度的摻鎵氧化鋅薄膜，而透過研究發現當摻雜濃度過高時，也可製備出氧化鎵鋅的同源結構材料。通過KPFM量測薄膜的表面功函數並研究了其與擦電輸出之間的關係，而摻鎵氧化鋅的TENG輸出結果表明，與未摻雜的氧化鋅相比，輸出電壓和電流都受到摻雜濃度的影響有16及13倍的增益。而同源結構因其非規律性層狀結構反而會限制電荷的移動，並且會使電荷在傳遞時容易散射掉，使電荷無法儲存至更深位置，進而限制新的摩擦電荷進入，因此降低了儲存摩擦電荷的能力，抑制了擦電的輸出。

By taking advantage of charge transfer process between two materials upon friction for electrification, electricity can be harvested from mechanical energy as a new green energy source in an emerging device of triboelectric nanogenerators (TENG). Within the context of triboelectric materials, ZnO offers a great opportunity in tuning total carrier concentrations available on the surface for charge transfer due to its semiconducting properties and easy control over intrinsic defects such as oxygen vacancies and Zn interstitials through doping. In this study, ZnO thin films were grown first by magnetron sputter. Subsequently, Ga was doped into the as-sputtered ZnO thin films by thermal diffusion using different amounts of Ga metalorganic precursors under Ar gas flow at elevated temperatures. It is found that Ga doping concentration is proved to increases as increasing Ga precursors as Ga-doped ZnO until about 0.93 at%, above which Ga2O3(ZnO)n homologous structure forms. Nevertheless, the surface work function of the thin films measured by KPFM can still be tuned systematically and exhibits a decreasing trend with Ga fraction. The results prove that surface work function difference governs the charge transfer responsible for the output performance of TENG only for Ga doped ZnO thin films, where the output voltage and current of the ZnO film doped with 0.93 at% Ga can be dramatically enhanced by 16 and 13 times, respectively, compared to undoped ZnO film. However, the homologous structure prevents charges from being stored deeper in depth, thus reducing the ability to store triboelectric charges and suppressing triboelectric output even though the work function difference is larger.

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