請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/73152
標題: | 元素成分調控於鉍銻銅氧之熱電特性探討 Influence of Element Manipulation on the Thermoelectric Properties of BiCuTeO |
作者: | Hui-Ching Chang 張惠菁 |
指導教授: | 楊英杰(Ying-Jay Yang) |
關鍵字: | 熱電,鉍碲銅氧,熱傳,熱電優值,冷壓碇,熱壓碇, Thermoelectric,BiCuTeO,Thermal conductivity,Cold press,Hot press, |
出版年 : | 2019 |
學位: | 博士 |
摘要: | 隨著地球資源的過度消耗與可預見的能源短缺問題,發展新的能源是迫在眉梢的任務。熱電元件是具有發展潛力的綠色能源,因其能直接將熱能與電能相互轉換。但是,過低的能量轉換效率是目前阻礙熱電元件發展及普及化的原因之一。當前熱電研究的重點包括提升其熱電優值(ZT),與探討熱電材料的物理、化學機制。鉍碲銅氧(BiCuTeO)近年來的研究顯示該材料是具有潛力的熱電材料,適合被使用在中溫區(500~900 ºC)的應用中。在本論文中,利用調控鉍、碲、銅、氧四個元素的比例,並分別利用冷壓碇(Cold press)與熱壓碇(Hot press)技術,達到增進鉍碲銅氧塊材的熱電表現的目的。
材料的分析包含晶體結構,成份分析,以及熱電特性。由霍爾量測的結果顯示出鉍碲銅氧材料為P型半導體。X光晶體繞射顯示出該材料為多晶材料,而且,隨著元素的量調控,X光繞射圖譜中的雜項強度也跟著改變,表示雜項在樣品裡的比例有改變的趨勢。另外,不但主相裡的元素比例與所占樣品百分比跟著改變,樣品的顆粒大小也跟著變化。這些改變都會影響樣品的熱電表現。這些都會在這本論文裡有詳細的探討。 Thermoelectric (TE) devices that are used to convert waste heat directly into electricity address some of the problems of the prevailing energy crisis and global climate-change issues. Of the various TE materials that are available, metal oxides exhibit high thermal and chemical stability in air, so they are suited to many TE applications. However, in the mid-temperature region (from 500~900 ºC), most feature a TE figure of merit (ZT) that is less than the required value of 2. BiCuTeO is a good thermoelectric material, because it features an intrinsically low thermal conductivity and higher carrier concentration than BiCuSeO. This study manipulates the elemental composition in BiCuTeO to improve the thermoelectric performance of BiCuTeO. XRD and EPMA are used to determine the characteristics of samples and the thermoelectric properties are determined using ZEM and LFA. It is concluded that the manipulation of the elemental composition affects the fractional ratio and the properties of the secondary phases of a sample, which alters the thermoelectric performance of the sample. This study gives a detailed characterization and a discussion of the effect of manipulating the nominal elemental composition of BiCuTeO. The findings of this study are relevant to the search for novel high-performance TE materials. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/73152 |
DOI: | 10.6342/NTU201901177 |
全文授權: | 有償授權 |
顯示於系所單位: | 電子工程學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-108-1.pdf 目前未授權公開取用 | 8.28 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。