Effects of post-annealing on photoluminescence of Eu-doped ZnO microsphere for single-component white-light materials

The influence of post-annealing on optical properties of Eu-doped ZnO (ZnO:Eu 3+ ) microsphere synthesized by hydrothermal method has been studied. The intrinsic deep defect emission of ZnO and the transition emission of both 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 related to Eu 3+ have been observed under excitation at 325 nm. The photoluminescence (PL) spectra reveal that ZnO annealed in N 2 is more favorable for Eu 3+ being doped into ZnO, which is helpful to greatly enhance the red light emission of ZnO:Eu 3+ . Alkaline conditions are more conducive to the formation of intrinsic deep defects in ZnO lattice, but they are not so conducive to the doping of Eu 3+ ions into ZnO lattice. From Gaussian deconvolution analysis of PL spectrum for ZnO:Eu 3+ , it can be seen that intrinsic defects of ZnO in N 2 atmosphere may efficiently assist energy transfer from ZnO host to Eu 3+ ions to enhance Eu 3+ intrinsic red light emission. There are blue light (446 nm), green light (525 nm) and stronger red light (618 nm) which are simultaneously obtained. This work could pave a way for high performance of white light emission application.