Work

Effect of Ge substitution on carrier mobilities and thermoelectric properties of sintered p-type Ba 8 Ga 16+x Sn 30−x−y Ge y with the type-VIII clathrate structure

Year: 2012

Type: article

Abstract: Ge substitution for Sn in Ba 8 Ga 16 Sn 30 was attempted in order to improve its thermoelectric properties. Since the melting point was raised by the substitution, the sintering temperature could be increased. The resultant sintered samples exhibited higher thermal stabilities and fewer trapping state densities at grain boundaries, which weakened grain boundary scattering for carriers. For example, the Ba 8 Ga 16.4 Sn 25.0 Ge 4.6 and Ba 8 Ga 16.9 Sn 19.8 Ge 9.3 samples had larger room temperature mobilities of 6.7 cm 2 V −1 s −1 and 13.3 cm 2 V −1 s −1 , respectively, than that of 2.3 cm 2 V −1 s −1 of the Ba 8 Ga 16.6 Sn 29.4 sample. Consequently, these Ge-substituted samples had higher figures-of-merit maxima of 0.62 at 550 K and 0.63 at 600 K, respectively, than that of 0.36 at 500 K for the Ba 8 Ga 16.6 Sn 29.4 sample.

Source: Journal of Physics D Applied Physics

DOI: 10.1088/0022-3727/45/44/445306

Authors: K Kishimoto, H Yamamoto, K Akai, T Koyanagi

Institution: Yamaguchi University

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funder: Japan Society for the Promotion of Science

Awards: Localized states and thermoelectric properties of vacancy-containing Sn-based clathrate compounds, Research of High Performance Thermoelectric Materials with Nano-size Cages by focusing Random Host Structure of Quaternary Sn-based Clathrate Semiconductors