Interface effects on thermal conductivity of Bi/Te core-shell nanowires

The formation of variable 1D heterostructure including core-shell and tubular nanowire is of particular significance with respect to potential applications for the thermoelectric device with the enhanced figure of merit (ZT=S²σT/κ). We report Bi-Te core/shell and Te tubular nanowire fabrication based on the stress induced method. Fig. 1 schematically shows the nanowire fabrication process. Bi nanowires are grown on the Si substrate by the stress-induced method, and then Te is evaporated on the Bi nanowires. Fig. 2 is TEM image clearly shows core/shell structure for which effective phonon scattering and quantum confinement effect are expected. Our results demonstrate that various 1D heterostructure like Bi-Te core/shell and Te tubular nanowire can be grown successfully by the stress-induced method. Based on the result of electrical transport measurement and its characteristic morphology of rough surface, we will measure Seebeck coefficient and thermal conductivity in the future work.