Enhancement of the Thermoelectric Performance of Bi0.4Sb1.6Te3 Alloys by In and Ga Doping

• Published in: Journal of electronic materials Vol. 42; no. 7; pp. 1617 - 1621
• Main Authors: Lee, Kyu-Hyoung, Hwang, Sungwoo, Ryu, Byungki, Ahn, Kyunghan, Roh, Jongwook, Yang, Daejin, Lee, Sang-Mock, Kim, Hyunsik, Kim, Sang-Il
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01.07.2013; Springer
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Conductivity phenomena in semiconductors and insulators; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in condensed matter; Electronic transport phenomena in thin films and low-dimensional structures; Electronics and Microelectronics; Exact sciences and technology; Instrumentation; Materials Science; Optical and Electronic Materials; Physical properties of thin films, nonelectronic; Physics; Solid State Physics; Surface and interface electron states; Surface states, band structure, electron density of states; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thermal stability; thermal effects; Thermoelectric and thermomagnetic effects; Thermoelectric effects; lattice thermal conductivity; Te; Bi; Thermoelectric; power factor; point defect; Sb; Valence bands; Density of states; Point defects; Doping; Phonons; Polycrystals; Gallium additions; Synergism; Thermoelectric properties; Thermoelectric materials; Electronic structure; Thermal conductivity; Point defect scattering; Figure of merit
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-012-2356-3

We report an enhancement of the thermoelectric figure of merit in polycrystalline In- and Ga-doped Bi 0.4 Sb 1.6 Te 3 compounds. Via the controlled doping of In or Ga, the lattice thermal conductivity was effectively reduced by strong point-defect phonon scattering while the power factor was not significantly changed due to the similarity of the density of states near the valence-band maximum between undoped and In- or Ga-doped compositions. An enhanced ZT of 1.2 at 320 K was obtained in 0.5 at.% In-doped Bi 0.4 Sb 1.6 Te 3 compound by these synergetic effects.