Jpn. J. Appl. Phys. 42 (2003) pp. 6779-6783 |Next Article| |Table of Contents|
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Thermoelectric Characteristics of Si/Ge Superlattice Thin Films at Temperatures Less Than 300 K
Makoto Hamabe,
Hideaki Takahashi,
Satarou Yamaguchi,
Takashi Komine1,
Takashi Eura1,
Haruhiko Okumura2,
Yoichi Okamoto3 and
Jun Morimoto3
Department of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
1Ion Engineering Research Institute Corporation, 2-8-1 Tsuda-Yamate, Hirakata, Osaka 573-0128, Japan
2Matsusaka University, Matsusaka, Mie 515-8511, Japan
3Department of Materials Science and Engineering, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686, Japan
(Received October 4, 2002; revised June 12, 2003; accepted July 15, 2003; published November 10, 2003)
We have studied the thermoelectric characteristics of Si/GeAu superlattice thin films at temperatures ranging from 290 K to 75 K and compared them to those of the SiGeAu alloy thin film. In the annealed Si/GeAu superlattice, the electrical resistivity was lower than that of the unannealed Si/GeAu superlattice at all temperatures. The annealed Si/GeAu superlattice showed a high thermoelectric power of 105 µV/K at 290 K. At temperatures less than 200 K, however, the polarity of the thermoelectric power of the unannealed Si/GeAu superlattice switched from positive to negative and a large negative thermoelectric power of -4.6 mV/K was attained at 80 K. On the other hand, the characteristics of all samples showed no magnetic field effect at all temperatures. To explain the causes of the extremely small variations in the characteristics by the magnetic field effects, we calculated the transport coefficients for the SiGeAu alloy using the two-band parabolic model, and compared them to those of experimentally measured values. When a large amount of acceptor concentration from Au doping and the very low carrier mobility were assumed, similar transport coefficients to the measured ones resulted.
KEYWORDS:
thermoelectrics, superlattice, magnetic field effect, Seebeck effect, Hall effect
URL:
http://jjap.ipap.jp/link?JJAP/42/6779/
DOI: 10.1143/JJAP.42.6779
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