On the origin of photoluminescence in indium oxide octahedron structures

A sixfold decrease in photoluminescence signal intensity at 590nm with increase in deposition time from 3to12h has been observed in single crystalline indium oxide octahedron structures grown by vapor-phase evaporation method. Electron paramagnetic resonance and energy dispersive x-ray analysis confirm that the concentration of oxygen vacancies increases with deposition time. These results are contrary to the previous reports where oxygen vacancies were shown to be responsible for photoluminescence in indium oxide structures. Our results indicate that indium interstitials and their associated complex defects other than oxygen vacancies are responsible for the photoluminescence in In2O3 microstructures.