Low phonon thermal conductivity of layered (Bi-2)(m)-(Bi2Te3)(n) thermoelectric alloys

[摘要] We examined the thermal conductivity of the (Bi-2)(m)-(Bi2Te3)(n) alloys, which are composed of alternating sequences of Bi-2 and Bi2Te3 structural units. The phonon thermal conductivity of these alloys was sharply reduced relative to that of elemental Bi and Bi2Te3 for temperatures below 100 K. Our measurements suggested that defects reduce the thermal conductivity in these materials. Using the Debye-Callaway model for heat transport, we link this reduced thermal conductivity to point defects.

[关键词] TRANSPORT-PROPERTIES;ELASTIC-CONSTANTS;BISMUTH TELLURIDE;SINGLE-CRYSTAL;TEMPERATURE;SCATTERING;DEFECTS