Overview of Bismuth Nanowires for Thermoelectric Applications

Abstract

The goal of this workshop on thermoelectric materials “Beyond Bismuth Telluride” was to inspire researchers in the thermoelectrics field to think boldly about the future of Thermoelectrics Science and Technology and to identify what it would take to make a big step forward in this research area. The field of thermoelectrics advanced rapidly in the 1950s when the basic science of thermoelectric materials became well established, the important role of heavily doped semiconductors as good thermoelectric materials became accepted, the thermoelectric material bismuth telluride was discovered and developed for commercialization, and the thermoelectrics industry was launched. At that time it was established that the effectiveness of a thermoelectric material could in an approximate way be described in terms of the dimensionless thermoelectric figure of merit, ZT= S ²σT/κ where S, σ Tand κ are the Seebeck coefficient, the electrical conductivity, the temperature and the thermal conductivity. Over the following 3 decades 1960–1990, only incremental gains were made in increasing ZT, with Bi₂Te₃remaining the best commercial material at ZT≈ 1. During that 3 decade period, the thermoelectrics field received little attention from the worldwide scientific research community.^lNevertheless the thermoelectrics industry grew slowly but steadily, by finding niche applications for space missions, laboratory equipment, and medical applications, where cost and efficiency were not as important as energy availability, reliability, and predictability.