Tunable thermal conductivity of ternary alloy semiconductors from first-principles

We compute the thermal conductivity, kappa, of five representative III-V ternary alloys-namely In x Ga1 - x As, GaAs1 - x P x , InAs1 - x Sb x , GaAs1 - x N x , and GaP1 - x N x -in the whole range of compositions, and in zincblende and wurtzite crystal phases, using a first-principles approach and solving the phonon Boltzmann transport equation beyond the relaxation time approximation. We discuss the tunability of the thermal conductivity with the composition of the alloy, reporting a steep decrease in the thermal conductivity, followed by a wide plateau and a steep increase common in systems with lattice disorder. We also test the approximation consisting in considering impurities at small values of x as bare mass defects, neglecting their chemical identity, and discuss its validity.