Effect of macroscopic polarization on thermal conductivity of InN

• Macroscopic polarization property contributes to effective elastic constant of InN.
• Revised phonon velocity, Debye temperature and frequency have been estimated.
• Revised phonon scattering rates are calculated as a function of phonon frequency.
• Revised room temperature thermal conductivity of InN is enhanced from 132 to 156 W/m K.

The effect of macroscopic polarization on thermal conductivity of wurtzite InN has been theoretically investigated. The elastic constant, C44 of InN is contributed by macroscopic polarization; and modifies the phonon velocity, Debye frequency and Debye temperature. Using revised phonon velocity, different phonon scattering rates and combined scattering rate are calculated as functions of the phonon frequency at room temperature. The thermal conductivity of InN was estimated using these modified parameters. The theoretical analysis shows that up to a certain temperature the polarization effect acts as a negative effect and reduces the thermal conductivity. However, beyond this temperature the thermal conductivity is significantly enhanced by the polarization effect. The revised thermal conductivity at room temperature is found to be increased by 18% due to macroscopic polarization. The increased thermal conductivity can minimize the self heating effect of nitride optoelectronic devices. The method we have developed can be used for simulation of thermal energy in the active region of nitride optoelectronic devices.