  The thermal conductivities k of wurtzite InxGa1-xN are investigated using
equilibrium molecular dynamics (MD) method. The k of InxGa1-xN rapidly declines
from InN (k_InN = 141 W/mK) or GaN (k_GaN = 500 W/mK) to InxGa1-xN, and reaches
a minimum (k_min = 19 W/mK) when x is 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 k, is extrapolated in our simulation and a parabolic relationship between x
and MFP is established. We find that the k of InxGa1-xN decreases with
increasing temperatures. The evolution of k 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 k than experimental values, our calculated k 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.
