以電化學蝕刻法製備多孔隙矽薄膜及其儲能元件應用

Fabrication of Porous Silicon Films by Electrochemical Etching and Its Application for Energy Storage Devices

張志澤(Chang, Chih Tse)

指導教授 ： 闕郁倫

國立清華大學/工學院/材料科學工程學系/碩士(2015年)

摘要

本論文著重於開發以電化學蝕刻法製備之多種製程，並將多孔矽應用於能量儲存材料以及其降低太陽能電池之成本潛力。
矽(Si)是地球上含量第二豐富的材料，由於其低成本及良好的本質特性，目前已經被廣泛地應用在電池、半導體工業以及太陽能等產業，多孔結構的矽更是一良好的功能性材料。以電化學蝕刻法製備多孔矽為一方便且低成本之方法，此外，更能夠輕易達到大面積製造。由於矽的低成本且具有非常高的理論電容值，因此是非常良好的鋰電池陽極材料。然而其充放電時的體積膨脹容易導致結構破壞，因而降低電池的壽命。本論文提出將多孔矽膜製成矽奈米顆粒來改善結構，因而得到良好的電容、庫倫效率，以及電池元件壽命的增加。由於多孔矽的高比表面積特性，我們更進一步在矽晶圓上形成多孔矽，並藉由表面披覆數奈米的石墨烯，形成一具有高比電容及高穩定性的矽基超電容元件。在本論文的末端，為了要改善矽基太陽能電池之成本問題，我們利用控制奈米矽的結構，成功在矽晶圓基板上分離出具有可撓性的多孔矽薄膜及準單晶(quasi-monocrystalline)矽薄膜，並具有未來發展於太陽能電池產業之潛力。

關鍵字

多孔矽 ； 鋰離子電池 ； 超級電容器 ； 石墨烯

並列摘要

This thesis aims to develop several processes of electrochemical etched porous silicon for either energy storage devices or demonstrating its potential for silicon-based solar cells.
Silicon, the second most abundant material on earth, has been utilized in a wide range of regimes including batteries, semiconductor industry, and solar cells due to its low cost and well-developed technology. Porous silicon (PSi), as a functional material either due to its intrinsic property or the porous structure, has been presented to be fabricated by electrochemical etching, which is a facile and cost-effective method for producing porous silicon in a large scale. For lithium-ion batteries, the high theoretical capacity makes it a suitable candidate for anode material. However, the volume expansion during lithiation/delithiation limits its cycling performance. In this thesis, SiNPs produced from PSi has been exploited to lithium-ion batteries with excellent capacitance, columbic efficiency, and cycling retention. Porous silicon is further exploited as electrodes of supercapacitors after few-layer of graphene coating, showing competitive specific capacitance and stable cycling retention. In the last part of the results, porous silicon films and quasi-monocrystalline silicon films possessing extraordinary flexibility are exfoliated from silicon wafers, showing good potential for reusing the silicon wafers to reduce cost of Si-based solar cells.

並列關鍵字

porous silicon ； lithium-ion battry ； supercapacitor ； graphene

參考文獻

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