Fabrication and performance of Lu_2O_3:Eu~(3+) nanowire arrays with different nanowire diameters

摘要

Lu2O3:Eu3+ nanowire arrays with different nanowire diameters were successfully fabricated by sol-gel process using submicron porous anodic aluminum oxide (AAO) templates. The nanowires in each array are homogeneous and highly ordered, and have uniform diameter defined by the template. They exhibit polycrystalline with Lu2O3 cubic structure. The crystallite sizes of the Lu2O3:Eu3+ nanowires increase with the increase of the pore diameters of AAO templates and are less than that of nanopowder prepared in the same conditions due to the confinement of AAO template on the coalescence of Lu2O3:Eu3+ nanocrystallites. The Lu2O3:Eu3+ nanowire arrays within AAO templates exhibit good performances of photoluminescence and X-ray excited optical luminescence. The emission peaks can be ascribed to D-5(0)- F-7(J) transitions of Eu3+ (J = 0, 1, 2, 3). The luminescent intensities of the Lu2O3:Eu3+ nanowire arrays also enhance with the increase of the pore diameters of AAO templates. This phenomenon is not only due to the increase of the filling ratio of Lu2O3:Eu3+, but also relates to the improvement of crystallinity. The latter mechanism is further confirmed by the fluorescent decay times of Eu3+ emission in the nanowires with different diameters. It is believed that the Lu2O3:Eu3+ nanowire array can become a promising high-spatial-resolution scintillation screen used in X-ray imaging.