Influence of Element Manipulation on the Thermoelectric Properties of BiCuTeO

• Main Authors: Hui-Ching Chang, 張惠菁
• Other Authors: Ying-Jay Yang
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/gx7f58

博士 === 國立臺灣大學 === 電子工程學研究所 === 107 === 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.