Thermal Conductivity Measurement of In_0.10Ga_0.90As_0.96N_0.04 Thin Film

Dilute indium gallium arsenide nitrides (In_xGa_1-xAs_1-yN_y) are valuable in photonic applications as long wavelength emitters and for pairing with silica optical fibers for low attenuation optical fiber communications. The reliable operation of these devices is tied to a precise temperature control and the knowledge of the thermal properties of their components. However, the thermal conductivity of bulk or thin film InGaAsN of any composition are, to the best of our knowledge, not available in literature. In response, we use time-domain thermoreflectance (TDTR) to measure the thermal conductivity of a 78 nm In_0.10Ga_0.90As_0.96N_0.04 film grown by metalorganic chemical vapor deposition (MOCVD) on GaAs substrate. The thermal conductivity of In_0.10Ga_0.90As_0.96N_0.04 is found to be 6 +/− 0.5 Wm⁻¹K⁻¹, a factor of two lower than that of bulk In_0.10Ga_0.90As. To our knowledge this is the first reported thermal conductivity measurement on InGaAsN. We also present an analytical model for predicting the thermal conductivity of InGaAsN for any composition. Using this model, we find that the reduction in thermal conductivity can be attributed to the scattering of phonons by nitrogen impurities and boundary scattering of long mean free path phonons from the film thickness.