Thermoelectric properties of SiC thick films deposited by thermal plasma physical vapor deposition

✍ Scribed by X.H Wang; A Yamamoto; K Eguchi; H Obara; T Yoshida

• Publisher: Institute of Physics and National Institute of Materials Science
• Year: 2003
• Tongue: English
• Weight: 348 KB
• Volume: 4
• Category: Article
• ISSN: 1468-6996
• DOI: 10.1016/s1468-6996(03)00015-9

✦ Synopsis

SiC thick films of about 300 mm could be prepared with a deposition rate above 300 nm/s by thermal plasma physical vapor deposition (TPPVD) using ultrafine SiC powder as a starting material. The thermoelectric properties were investigated as a function of composition and doping content. The nondoped films showed n-type conduction. Although the Seebeck coefficient reached as high as 2 480 mV/K, the power factor was only around 1.6 £ 10 24 W m 21 K 22 at 973 K due to the relatively high electrical resistivity. In order to reduce the electrical resistivity and to deposit layers with n-type and p-type conduction, N 2 , B and B 4 C were selected as the dopants. Nitrogen-doped samples exhibit n-type characterization, B and B 4 C-doped samples exhibit p-type characterization, and the electrical resistivity decreased from 10 22 -10 23 to 10 24 -10 25 V m after doping. The maximum power factor of the nitrogen-doped SiC and the thick films deposited with B 4 C powder reached 1.0 £ 10 23 and 6.4 £ 10 24 W m 21 K 22 at 973 K, respectively.