Thermal Transport Modulation via Interfacial Vacancy Defects in Carbon/Boron Nitride Heteronanotubes

Thermal transfer regulation of one-dimensional heterostructure is essential, but the influence of vacancy defects on interfacial thermal conductance (ITC) remains unclear. In this paper, we demonstrate that vacancy defects at the carbon/boron nitride heteronanotubes (CBNNT) significantly reduce the ITC, with N atoms vacancy exhibiting a more pronounced inhibitory effect than C atoms vacancy. This decline in ITC is attributed to vacancy-induced lattice distortions that diminish the overlap of the phonon density of states, ultimately enhancing phonon localization. Spectral heat current analysis confirms that vacancy defects markedly suppress phonon transport across the interface. Polarization-resolved decomposition further reveals that out-of-plane phonon modes dominate interfacial heat conduction but exhibit higher sensitivity to structural defects. Moreover, increasing temperature enhances phonon excitation and inelastic scattering, thereby facilitating low-frequency phonon transport and improving ITC. These findings provide atomic-scale insights into vacancy defect-modulated heat transport in low-dimensional nanostructures.