Fabrication of Microdevices for Investigating One-Dimensional Thermoelectric Properties

• Main Authors: Tsung-Hsun Li, 李宗勳
• Other Authors: 李勝偉
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/03816671063965606877

碩士 === 國立中央大學 === 材料科學與工程研究所 === 103 === Energy is one of the most important issues today. For efficient use of energy, there has been much research in the search for new materials for advanced thermoelectric energy conversion applications. Thermoelectricity is the conversion between heat and electricity. “Thermoelectric (TE) materials” is used to describe the materials that are good at converting heat to electricity. By converting waste heat into electricity through the thermoelectric power of thermoelectric materials without producing greenhouse gas emissions, thermoelectric generators can be an important part of the solution to today’s energy challenge. In recent years, low-dimensional materials of semiconductor have been proved to be potential as thermoelectric materials. In order to experimentally investigate the TE properties in one-dimensional materials in a systematic manner, it is necessary to measure the TE parameters of samples with precisely controlled dimensions. For this purpose, we batch-fabricated suspended micro-fabricated devices for measuring thermal and electrical transport in lightly- and heavily-doped Si nanowires (SiNWs) prepared using metal-assisted chemical etching. The resulting nanowire is placed on a micro-fabricated device by micro-manipulation. We found that the heavily-doped SiNW has lower thermal conductivity and Seebeck coefficient than lightly- doped SiNW, resulting in higher ZT values. We attempt to explain these results in terms of surface roughness and porosities of SiNW caused during the metal-assisted chemical etching.