面臨全球的能源危機，傳統能源的污染問題和不可再生性，可再生能源諸如風力發電、水力發電與太陽能發電等又有著設備搭建的特殊環境要求，科學家們不斷尋找新的可以發電的方式來填補我們的用電需求。為了利用自然界存在最廣泛的機械能，科學家們發明了基於材料熱電、壓電等性質的各種發電手段，2012年，王忠林教授團隊提出了摩擦電微型發電機的構想，將很早就被發現但是一直被認為是負面效應的摩擦生電利用了起來，描繪出一種新的將動能轉化為電能的方式。由於產生摩擦的方式多種多樣，摩擦現象在日常生活中無處不在，這大大提升了摩擦電微奈米發電機的應用領域。從摩擦電發電機發明至今，大多數的研究都專注于現有材料的優化或是發電機結構的優化，很少有研究去使用新的摩擦材料。氧化鋅作為一種人們熟悉的半導體材料，有研究使用它來充當摩擦材料，但是輸出並不是很理想。摻雜鎂作為一種有效的改變氧化鋅性質的手段，已經被證實可以改善它的壓電輸出，我們好奇它是否也能夠改變擦電輸出。
本實驗使用磁控濺鍍製作氧化鋅鎂薄膜，通過改變濺鍍參數來改變氧化鋅鎂薄膜的參數，再將氧化鋅鎂薄膜與PDMS薄膜作為摩擦材料，組裝成摩擦電微發電機。我們通過SKPM記錄薄膜有效功函數并研究了它與擦電輸出之間的關係，對於發擦電荷產生的機理有了更直觀的認識；我們在實驗結果的基礎上，提出了兩個會影響到材料有效功函數的因素：鎂含量與薄膜成長方向。與氧化鋅相比，氧化鋅鎂能將擦電輸出提升至少55倍。

Since the invention of triboelectric nanogenerator (TENG), the output performance of TENG have been attempted to be improved through various approaches such as material surface modification, device structure optimization and so on, but rarely through developing new friction materials. In this work, magnetron sputter MgxZn1-xO film is developed as a viable friction material, which is rubbed against PDMS in TENG. The work function, measured by kelvin probe microscopy, of MgxZn1-xO film can be effectively varied by varying composition, x, and the exposed surface facets through preferred growth orientation, which is shown to dominate the output power of TENG. In addition, film thickness also plays an important role in the output of TENG. As a result, the output voltage of the TENG of MgxZn1-xO film is demonstrated to be tremendously enhanced by at least 55times, when compared to that of ZnO film. Even more intriguingly, the tribo-output polarity can be reversed by adjusting the relative work function through varying preferrred growth orientation of the MgxZn1-xO film, when keeping the same Mg content.

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