Effect of Nanostructure and Europium Doping on Fluorescence Properties of YbxMnyOz:Eu3+ Nanotube Arrays

YbxMnyOz:Eu3+ nanotube arrays have been synthesized in anodic aluminum oxide (AAO) templates with negative pressure filtration. The morphology, structure, and composition have been characterized by SEM, TEM, HRTEM, XRD and EDS, respectively. Compared with nanoparticles and nanowire arrays excited by 394 nm light wave, YbxMnyOz:Eu3+ nanotube arrays exhibit fluorescence enhancement and are accompanied by red and blue shift, and there are three fluorescence emission peaks at 480 nm, 590 nm and 702 nm, respectively. The peaks at 590 and 702 nm correspond to the 5D0–7F1 and 5D0–7F4 energy level transition of Eu3+, and the peak of 480 nm is from the “cooperative fluorescence” due to two-photon excitation. The fluorescence intensity of YbxMnyOz:Eu3+ nanotube arrays increases with the doping concentration of Eu3+, which reaches a maximum at 5 vol %, and remarkably decreases at higher concentrations.