Abstract
The thermal conductivities kappa of wurtzite InxGa1-xN are investigated using equilibrium molecular dynamics (MD) method. The kappa of InxGa1-xN rapidly declines from InN (kappa InN = 141 W/mK) or GaN (kappa GaN = 500 W/mK) to InxGa1-xN (x =/ or 1), and reaches a minimum (kappa min = 19 W/mK) when xis around 0.5 at 300 K. The mean free path (MFP) of InxGa1-xN, ranging from 2 to 5 nm and following the same trend with the kappa, is extrapolated in our simulation and a parabolic relationship between x and MFP is established. We find that the kappa of InxGa1-xN decreases with increasing temperatures. The evolution of kappa of InxGa1-xN is also examined by projecting the momentum-energy relationship of phonons from MD trajectories. The phonon dispersion and phonon density of states for InxGa1-xN reflect a slightly more flattened dispersive phononic curve of the alloying system. Despite an overestimated kappa than experimental values, our calculated kappa at 300 K agrees well with the results obtained by solving Boltzmann transport equation and also has the same stoichiometric trend with the experimental data. Our study provides the coherent analysis of the effect of thickness, temperature and stoichiometric content on the thermal transport of InxGa1-xN which is helpful for the thermal management of InxGa1-xN based devices.
NSTL
Elsevier