14 - The measurement of thermoelectricity

Abstract

After a brief boom in the 1960s, Thermoelectric (TE) materials have attracted renewed interest. During the late 1990s, TE materials started to be used commercially, for example, in the cooling system for an optical fiber relay station in Japan. New TE materials have started to emerge, including oxide, skutterudite delforssite, clathrate, alongside more established materials, such as bismuth telluride and silicon germanium. TE devices are, however, still at an early stage of development. In particular, their use in power generation has suffered because of lower efficiency compared to solar energy. In addition, there had not been a standardized system of measurement until a Japanese Industrial Standard (JIS) was established. The Japanese Industrial Engineering Bureau established a committee to develop the measurement of TE materials in 1998. The author chaired the committee of seven drawn from both industrial and academic fields. In its first year, the committee conducted research among companies, national institutes, and universities on thermoelectric energy conversion, commercial applications, and future trends. Finally, the committee analyzed the data it had gathered, and producing three JIS volumes on TE in 2002, covering the Seebeck coefficient, electrical resistivity, and thermal conductivity, including diffusivity and heat capacity. This chapter discusses the measurements of thermoelectricity (Seebeck coefficient), electrical resistivity, and thermal conductivity as set out in the JIS document.