2009 Fiscal Year Final Research Report

Development of liquid-phase growth process for Bi_2Te_3-based Thermoelectric Materials

Research Project

Project/Area Number	20760494
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Material processing/treatments
Research Institution	Shimane University
Principal Investigator	KITAGAWA Hiroyuki Shimane University, 総合理工学部, 准教授 (00325044)
Project Period (FY)	2008 – 2009
Keywords	熱電変換材料 / 液相成長法 / キャリア輸送特性
Research Abstract	A liquid-phase growth process of Bi_2Te_3-based materials was developed in order to obtain polycrystals with a preferred orientation for use in thermoelectric applications. The liquid-phase growth was carried out under an argon atmosphere by using the sliding-boat method, which is an easy and short-time process compared with the conventional method for preparing the single crystals. X-ray diffraction patterns show that the hexagonal c-plane of the grown crystal is almost parallel to the substrate. The Hall mobility of the grown crystal (p-type Bi_<0.5>Sb_<1.5>Te_3) was 1.8～2 times larger than that of the sintered materials with a comparable carrier concentration. As a result, the thermoelectric power factor was improved by this process because of the low electrical resistivity due to the high carrier mobility.

(4 results)