A Kinetic-Collective model of phonon heat transport is used to calculate the thermal conductivity of bulk Bi2 Te and nanowires with diameters ranging from 350 to 50 nm, oriented in the [110] direction from low temperatures up to above room temperature. This model accounts for the role of normal (momentum-conserving) collisions in thermal transport, and provides a more accurate prediction of the thermal conductivity as shown elsewhere on other materials [1,2]. Within this model, the thermal conductivity is explained as a combination of a kinetic and a collective phonon heat flux with significantly different contributions. Nanowires with 350 and 120 nm in diameter have been grown in the [110] direction. easurements of their thermal conductivity at room temperature agree very well with th e theoretical predictions. Furthermore, the figure of merit ZT is expected to increase considerably for the 120 nm NW under certain values of the applied voltage across the sample, while the 350 nm NW remains with near bulk values.

Póster presentado en la 12th European Conference on Thermoelectricity (ECT2014), celebrada en Madrid del 24 al 26 de septiembre de 2014.

Peer Reviewed