We develop a strategy to investigate bridge role of O-related defects in the neighbor of Eu3+ in energy transfer (ET). By solvothermal reactions and following annealing process, Eu3+ doped ZnO nanocrystal is synthesized. After low-temperature annealing, Eu3+ ions occupy substituted sites of ZnO. High temperature annealing results in self-purification process - the separation of Eu3+ ions from ZnO lattice and generation of Eu2O3 precipitate phases. However, in this case, the proportion of individual Eu2O3 particles is extremely low if they are separated. The precipitate phases have paralleled edges and parallel to (011̄1̄) plane of ZnO. By self-purification separation, these O-terminated planes are easy to couple with Eu3+ ions, and form Eu3+ trap state. In order to maintain hexa-coordinate of Eu3+ ions, many O-related vacancies and interstitial defects are generated in the interface of ZnO/Eu2O 3, among which interstitial O (Oi) in the neighbor of Eu3+ ions plays an important role in balance charge and ET. Thus, it is not strange to observe enhanced luminescence peak in self-purified samples.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)