Characteristics of InN grown on SiC under the In-rich regime by molecular beam heteroepitaxy

InN epitaxial films were grown by $N2$ plasma-assisted molecular beam epitaxy on 4H- and 6H-SiC substrates using low-temperature InN nucleation layers. InN films grown at various In fluxes under the In-rich regime show improved crystal quality, surface morphology, and optical properties, without sizable metallic In incorporation. Photoluminescence measurements show emission up to room temperature, band gap values as low as $0.64eV$ at $T=10K$⁠, and carrier concentrations of the order of $8×1017cm−3$⁠.