Phonon Dominated Thermal Transport in Metallic Niobium Diselenide from First Principles Calculations

Niobium diselenide (NbSe2) is a layered transition metal dichalcogenide material which possesses unique electrical and superconducting properties for future nanodevices. While the superconducting, electrical, and bulk thermal transport properties of NbSe2 have been widely studied, the in-plane thermal transport property of NbSe2, which is important for potential thermoelectric applications, has not been thoroughly investigated. In this report, we study the lattice in-plane thermal transport of 2D NbSe2 by solving the phonon Boltzmann transport equation with the help of the first principles calculation. The thermal conductivity obtained at room temperature is 12.3 W/mK. A detailed analysis shows that the transverse acoustic phonon dominates the lattice thermal transport, and an anomalously small portion of electron contribution to the total thermal conductivity is observed for this metallic phase. The results agree well with experimental measurements and provide detailed mode-by-mode thermal conductivity contribution from different phonon modes. This study can provide useful information for integrating NbSe2 in nanodevices where both electrical and thermal properties are critical, showing great potential for integrating monolayer NbSe2 to thermoelectric devices.

Automated summary

In this study, the in-plane thermal transport property of 2D NbSe2 was investigated using first principles calculation. The results showed that the thermal conductivity of NbSe2 at room temperature is 12.3 W/mK. Transverse acoustic phonons were found to dominate the lattice thermal transport, and electron contribution to the total thermal conductivity was observed to be anomalously small in this metallic phase. The results were consistent with experimental measurements and provided detailed information on thermal conductivity contribution from different phonon modes. This study is important for integrating NbSe2 in nanodevices where both electrical and thermal properties are critical, demonstrating its great potential for thermoelectric devices.