Orange Photoluminescence from Hydrothermally Grown Zno Nanorods and Study on its Defects

The visible photoluminescence (PL) of ZnO is controversial for a long time. At present, the contribution of oxygen interstitial defects to yellow/orange emission from ZnO nanostructures is on debate. In this report, the origin of orange emission from solution- grown ZnO nanorods is investigated using excitation wavelength dependent photoluminescence PL, PL excitation and UV-Vis spectra. These results showed that orange emission may be due to the transition of an electron from shallow defect levels positioned slightly below the conduction band to the singly ionized oxygen vacancies. Hence, it is believed that oxygen interstitials may not be responsible for orange emission from solution grown ZnO nanostructures.