Lattice thermal conductivity of boron nitride nanoribbon from molecular dynamics simulation

Abstract

The lattice thermal conductivity of boron nitride nanoribbon(BNNR) is calculated by using equilibrium molecular dynamics (EMD) simulation method. The Green–Kubo relation derived from linear response theory is used to acquire the thermal conductivity from heat current auto-correlation function (HCACF). HCACF of the selected BNNR system shows a tendency of a very fast decay and then be followed by a very slow decay process, finally, approaching zero approximately within 3 ps. The convergence of lattice thermal conductivity demonstrates that the thermal conductivity of BNNR can be simulated by EMD simulation using several thousands of atoms with periodic boundary conditions. The results show that BNNR exhibit lower thermal conductivity than that of boron nitride(BN) monolayer, which indicates that phonons boundary scatting significantly suppresses the phonons transport in BNNR. Vacancies in BNNR greatly affect the lattice thermal conductivity, in detail, only 1% concentration of vacancies in BNNR induce a 60% reduction of the lattice thermal conductivity at room temperature.