石墨烯與矽之蕭基接面光電化學元件於產氫之研究

Graphene-silicon Schottky Junction Photoelectrochemical Cells for Hydrogen Generation

陳俊吉(Chun-Chi Chen)

指導教授 ： 陳俊維

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201601253

摘要

由單層碳原子所組成的石墨烯，因為特殊的能帶結構以及原子排列方式，而擁有許多優異的性質，例如可調變的功函數、高穿透度、高載子遷移率、易被化學修飾等等，這些性質使得石墨烯具有相當的潛力應用於透明電極領域。從文獻中可以發現，石墨烯大多應用於與矽形成蕭基接面之太陽能電池中。然而，可再生能源的應用相當廣泛，除了利用太陽能電池把太陽能轉換成電能之外，近幾年來氫能的重要性也日益漸增，因此如何利用石墨烯與矽形成的蕭基接面作為光電化學元件應用於產氫為我的研究主軸。
在此論文的第一部分，我們成功把石墨烯與矽形成的蕭基接面應用於強酸中做為產氫的光電極，搭配特殊的介面處理製程消除石墨烯與矽晶間原生氧化層進而改善元件表現，最後分析石墨烯在與矽形成的蕭基接面光電化學元件中扮演的角色。在第二部分，我們同樣利用石墨烯與矽形成的蕭基接面，將光觸媒白金運用照光沉積的方式還原於石墨烯的表面，最後得到的起始電壓和純矽元件相比有+0.4V的改善。此外成功利用光沉積法沉積白金也再次應證了第一部分中所得到提升元件表現是因為形成之蕭基接面可增加電荷分離效率的結論。

關鍵字

石墨烯 ； 蕭基接面 ； 光電化學元件 ； 產氫

並列摘要

Graphene, a two-dimensional (2D) network of hexagonal-structured and sp2-hybridized carbon atoms has a lot of remarkable properties, such as tunable work function, high transparency, high carrier mobility and the potential to be modified with chemical dopants. These properties make graphene really promising in transparent electrode in Schottky junction solar cell. However, beside electricity of the application for solar energy, hydrogen energy has also attracted much attention recently. As a result, how to utilize graphene/silicon Schottky junction for photoelectrochemical cells (PEC) is my thesis topic.
In the first part of this thesis, we successfully demonstrated graphene/silicon Schottky junction photoelectrochemical cells for hydrogen evolution reaction (HER). With the interfacial cleaner BOE treatment, the hole trap problem can be solved and hence onset potential has anodic shift. Next, we analyze the BOE treatment effect and evaluate the role of graphene in silicon Schottky junction PEC. In the second part, we utilize graphene/silicon Schottky junction to decorate the device with Pt catalysts through photo-deposition method. The final optimized device has significant anodic shift of the onset. In comparison to bare Si with the onset of -0.2 V vs. RHE, the onset potential is shifted positively by 0.4 V. In addition, the success of Pt deposition is a proof-concept of charge separation enhancement of graphene/silicon Schottky junction.

並列關鍵字

graphene ； Schottky junction ； photoelectrochemical cell ； hydrogen generation

參考文獻

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