Photoluminescence of cubic InN films on MgO (001) substrates

摘要

We have studied photoluminescence from cubic InN films grown on MgO substrates with a cubic GaN underlayer by RF N_2 plasma molecular beam epitaxy. A single PL peak was observed at 0.47 eV, By analyzing the reflectance spectra of cubic InN films, we could derive the refractive index and-extinction coefficient, and found the band gap energy of cubicrnInN is 0.48 eV, indicating that the PL peak observed at 0.47 eV is due to the interband transition of cubic InN. The difference in the PL peak energy between hexagonal and cubic InN is in good agreement with that predicted by ab-initio calculations.