Mie Resonant Absorption and Infrared Emission in InN Related to Metallic Indium Clusters

We demonstrate that resonant optical losses related to metallic In clusters can significantly modify absorption spectra of InN with any optical gap. Thermally detected absorption spectra with a pronounced Mie resonance are successfully simulated using a dielectric function of InN corresponding to the 1.2–1.4 eV optical gap. The resonance is observed in spectra of conventional absorption at low temperatures being smoothed out at room temperature.