Unusual violet photoluminescence in indium-doped ZnO nanowires

摘要

Point defects in wide bandgap semiconductors such as ZnO are emerging as promising candidates for single photon sources. However, identification of defect-based luminescence is rather difficult due to the extremely complicated defect physics of ZnO. Here, we report an unusual violet emission centered at 3.1 eV from indium-doped ZnO nanowires. The violet emission can be observed only below 180K and shows thermal quenching with unexpectedly small activation energy of similar to 36 meV. Photoluminescence and X-ray absorption near edge spectroscopy results suggest that the origin of the violet emission is VZn-InZn complex defect. The overall luminescence features can be understood in terms of the configuration coordinate model involving intercross between the potentials of the ground and excited states. Our results may give insights into the defect physics and be essential to the optoelectrical properties of doped ZnO nanostructures. Published by AIP Publishing.