Preparation of ZnO:Eu3+ nanospheres via a micro-emulsion method and analysis of the photoluminescence properties.

Abstract

ZnO:Eu3+ nanospheres were prepared via a micro-emulsion method with hexadecyl trimethyl ammonium bromide as the primary surfactant, butanol as the cosurfactant and octane as the oil phase. The X-ray diffraction (XRD) pattern suggests that the Eu3+ ions have entered into the ZnO lattices. Scanning electron microscopy (SEM) images show that large scale-shaped nanospheres about 200-500 nm in size were formed. The photoluminescence (PL) spectra suggest that the Eu3+ ions doped into ZnO have located at the non-inversion center positions because only the 612 nm peak (5D0 --> 7F2) occurred in the emission spectra. A schematic drawing for the possible mechanisms of electron transitions in the PL excitation and emission spectra is also proposed.