摩擦式奈米元件內摩擦介電層的厚度與元件效能的關係與探討

Exploring the Relationship between the Thickness of the Tribo-dielectric Layer and Efficiency of a Triboelectric Nanogenerator

吳政璋(Cheng-Chang Wu)

指導教授 ： 廖洺漢

國立臺灣大學/工學院/機械工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201900860

摘要

隨著人類對能源的需求逐年增加，人們近年來不停地尋找各種替代能源，例如：太陽能、風能、潮汐能、地熱能和生質能。然而，即使有這些再生能源的出現與開發，仍無法成為現今人類消耗大量能量的主要來源。因此，一種藉由奈米科技用於儲存能量的新技術就被發展起來，那就是奈米發電機(nanogenerators)。奈米發電機中，最具有發展潛力的就是由喬治亞理工提出的摩擦式奈米發電機(triboelectric nanogenerators, Tengs)，它自2012年興起，至今是個新興且熱門的研究領域。
為了增加摩擦式奈米元件的輸出功率，我們可以從許多不同的面向著手，像是可以從電極以及摩擦介電層(tribo-dielectric layer, TDL)加入微結構，或是改變微結構的形狀或尺寸，都可以增加元件的效能。而這篇論文探討的是：摩擦介電層的厚度與元件的開路電壓(open-circuit voltage)以及短路電流(short-circuit current)之間的關係。相較於傳統的靜態模型，當摩擦介電層的厚度極薄時，以動態模型更能符合元件的輸出結果，同時也引進了一個材料參數，那就是動態模型中，在摩擦介電層附近的電子電洞再結合的比率r。透過數學算式的推導，可得到短路電流與摩擦介電層的厚度d是有關的，而開路電壓卻是無關的。此外，可以發現在某個特定的厚度值(dmax)時，會有最佳的電流值(Imax)，且隨著材料的r值增加，Imax會隨之減少而dmax卻隨之增加。
最後，透過實驗的方式驗證理論模型的正確性，不僅推測出以聚二甲基矽氧烷(PDMS)當作摩擦介電層的r值，也推測出其他國外實驗的r值。

關鍵字

奈米發電機 ； 摩擦式奈米發電機 ； 聚二甲基矽氧烷 ； 摩擦介電層 ； 動態模型 ； 開路電壓 ； 短路電流

並列摘要

As the human demand for energy has increased year by year, people are constantly looking for alternative energy sources such as solar energy, wind energy, tidal energy, geothermal energy, and biomass energy recently. However, even with the emergence and development of these renewable energy sources, it is still unable to become a large amount of energy consumed by humans today. Therefore, there is a new technique developed for harvesting the energy by nano-technique called nanogenerator. One of the potential nanogenerators is triboelectric nanogenerators (Tengs), which is proposed by Georgia Tech. and has emerged since 2012 and that is still an emerging and popular research area.
In order to improve the output performance of Tengs, we can try at different aspects. For example, building up microstructure in electrode and tribo-dielectric layer (TDL) or changing the shape or size of microstructure can both increase the efficiency of Tengs. This article talks about the relationship between the thickness of TDL and open-circuit voltage or short-circuit current of a teng. Compared with static model, the dynamic model is more suitable for the output of tengs with ultra-thin thickness of TDL and we introduce one material parameter, i.e. electron-hole recombination rate (r) near the TDL in our developed dynamic model. By mathematical method, it can be derived that short-circuit current is dependent with different thickness of TDL, but open-circuit voltage is not. Furthermore, it can be found that there is a maximum current (Imax) at certain value of thickness (dmax), and the larger value of r in the material results in the smaller value of Imax and the larger value of dmax.
Finally, the experimental data and the theoretical dynamic model agree very well with each other and find out the value of r not only for polydimethylsiloxane (PDMS) as TDL but also for other foreign experimental data.

並列關鍵字

nanogenerator ； triboelectric nanogenerator ； polydimethylsiloxane ； tribo-dielectric layer ； dynamic model ； open-circuit voltage ； short-circuit current

參考文獻

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(https://arstechnica.com/information-technology/2017/03/intel-is-keeping-moores-law-alive-by-making-bigger-improvements-less-often/)

[2] Zhong Lin Wang, “Nanogenerators for self-powered devices and systems”, Georgia Institute of Technology, SMARTech digital repository, 2011.

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