Thermoelectric properties of amorphous AlInN thin films

Shigeo Yamaguchi 1,2Ryohei Izaki 1Yasuo Iwamura 1,2Atsushi Yamamoto 2

1. Kanagawa University, Department of Electrical, Electronic and Information Engineering, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
2. National Institute of Advanced Industrial Science and Technology, Energy Electronics Institute, AIST Tsukuba Central 2 Umezono 1-1-1, Tsukuba 305-8568, Japan

Abstract

Seebeck effect can cause solids to directly convert heat energy into electric energy without producing emissions such as carbon dioxide gas and radioactive substances. Moreover, using the reverse effect, Peltier effect, the simultaneous cooling and heating phenomena can be utilized to medical applications such as the local cooling or heating for the human body. There has recently been a great increase in the research and development of thermoelectric power generation systems that are designed to employ the vast resources of waste heat and environmentally sound cooling. The realization of practical applications associated with such systems requires the achievement of a high efficiency characterized by electric resistivity, thermoelectric Seebeck coefficient and thermal conductivity. At this stage, no binary compounds better than Bi2Te3, PbTe have been found. We have recently studied the thermoelectric properties of AlInN system in terms of substituting it for Be2Te3 and PbTe, which are considered to environmentally stress. AlInN thin films were prepared by reactive RF sputtering grown on SiO2 glass substrates. They were of amorphous, judging from X-ray analysis. We evaluated the values of Seebeck coefficient and electrical resistivity. Between the temperatures from RT to 873K, with increasing In content in AlInN from 0.45 to 0.84, the absolute value of the Seebeck coefficient decreased. Moreover, with increasing temperature, the Seebeck coefficient increased monotonically to be 70μ V/K at 873K. On the other hand, the resistivity decreased with increasing temperature, and it was about 10-5 Ω m. Considering both Seebeck coefficient and resistivity, we estimated the value of power factor, which is a landmark for the applicational potential, and we obtained the value of over 10-4W/mK2. This value is smaller only by a factor of 10 compared to those for Bi2T3 and PbTe. We believe that AlInN can take place of them in the near future.

 

Presentation: poster at E-MRS Fall Meeting 2003, Symposium A, by Shigeo Yamaguchi
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-05-27 14:03
Revised:   2009-06-08 12:55