Brilliant blue, green and orange-red emission band on Tm3+-, Tb3+- and Eu3+- doped ZrO2 nanocrystals

Tm3+-, Tb3+- and Eu3+- doped ZrO2 nanocrystals were prepared by a facile precipitation method with a hydrothermal process. Structural characterization showed a crystallite size ranging from 30 to 40 nm, and monoclinic and tetragonal zirconia phases were observed depending on the dopant concentration. The monoclinic phase was dominant for 0.5 mol% of Tb3+ and Eu3+, and the tetragonal phase was 100% stabilized for 2 mol% of Tm3+ and Tb3+. The structure of emission bands associated with Eu3+ confirms the substitution of Zr4+ located at C-1 and D-2h symmetry sites for the monoclinic and tetragonal phases. The emission of three primary colours, red, green and blue, was obtained from Eu3+, Tb3+ and Tm3+, respectively, which makes this nanophosphor an excellent candidate for use in photonics applications. The emitted signal was analysed as a function of ion concentration and the optimum concentration was determined.