Temperature dependent Raman of BiTe nanotubes

BiTe has been widely used as thermoelectric material. Here the BiTe nanotubes were synthesized by solvothermal method for the first time. The BiTe nanotubes were characterized via scanning electron microscope (SEM), X-ray diffraction (XRD) as well as transmission electron microscope (TEM), indicating the high crystal qualities of as-prepared products. The lattice dynamics of BiTe nanotubes was further studied via the micro-Raman scattering spectra in the temperature range of 103-593 K. Both the peak position and mode width of 2Ag1, 1Eg1 exhibit an obvious change with decreased temperature. All the Eg1, A1g1, Eg2, A1g2 modes have ultralow temperature coefficients of 1.85 × 10−5, 1.98 × 10−4, 1.09 × 10−4, 2.34 × 10−4 cm−1/K, respectively, which should be beneficial for obtaining high figure of merit (ZT) and confirm the outstanding thermoelectric performance of BiTe nanotubes.