奈米碳管(Carbon Nanotubes, CNTs)是碳的一維同素異構體，其電性、熱性及結構使其能夠實現高效率的熱電能量交換。熱電轉換分成熱電效應(Seebeck Effect)與電熱效應(Peltier Effect); 前者為透過材料冷熱端的溫度梯度形成電位差，後者則是利用電位差產生材料兩端的冷熱差。良好的熱電材料需要高的熱電優值(zT值)，及同時具備高導電率、低熱傳導率與高熱電係數，才會有明顯的熱電能量轉換。本研究使用多壁奈米碳管(Multi-Walled Carbon Nanotubes, MWCNTs)與紙纖維混合後形成的可撓式導電碳管紙複合材料，透過高溫熱置換硼摻雜(Boron doping)與氮氣電漿改質處理，分別製備了p-type與n-type的半導體特性碳管紙，並嘗試將樣品組成熱電致冷裝置(Thermoelectric cooler, TEC)，期望能觀察到致冷效果及材料冷熱端溫差。
本研究團隊過去曾研究出一種具有熱電效果的奈米碳管紙複合材料，其中一端經由氮氣電漿處理過後而有n-type摻雜，另一端則為未處理的樣品。本研究為了提升複合材料的熱電效果，採用硼摻雜的奈米碳管取代純奈米碳管，成功藉由硼摻雜讓p-type的電洞增加進而增強Peltier效應，使熱電元件具有較大的溫差。實驗室過去研究指出30 wt%的多壁奈米碳管濃度有最好的熱電表現，冷熱溫差最大，故本實驗也採用30 wt%的摻硼奈米碳管紙來製備熱電樣品。將p-與n-type碳管紙樣品透過電子顯微鏡、拉曼光譜、化學分析電子能譜儀進行材料分析，再將樣品拿去做熱電分析，霍爾效應及雷射閃光法量測，求得導電度、載子濃度、熱電係數、熱傳導係數，算出zT值，最後將p-與n-type碳管紙組合成致冷裝置並觀察致冷現象。

Carbon Nanotubes (CNTs) are one-dimensional allotropes of carbon, and their electrical, thermal, and structural properties enable efficient exchange of thermoelectric energy. Thermoelectric conversion is divided into the Seebeck effect and the Peltier effect; the former generates a potential difference across temperature gradient between hot and cold ends of a solid. The latter, on the other hand, utilizes the potential difference to create a temperature difference between two ends of a solid. A good thermoelectric material requires a high thermoelectric figure of merit (zT), along with high electrical conductivity, low thermal conductivity, and a high Seebeck coefficient for effective conversion of thermal energy.
In this study, flexible conductive papers made of multi-walled carbon nanotubes (MWCNTs, 30 w.t%) and paper fibers are chemically modified into p- and n-type respectively through plasma and B-doping techniques. Conductive papers are subjected to Hall-effect measurements, X-ray Photoelectron Spectroscopy (XPS), laser flash method, Raman spectroscopy and Scanning Electron Microscopy (SEM) to uncover conductivity, carrier concentration, Seebeck coefficient and zT value. Finally, p- and n-type conductive papers are assembled into Peltier devices, followed by temperature difference measurements.

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