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

Abstract

Tm 3+ -, Tb 3+ - and Eu 3+ -doped ZrO 2 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 Tb 3+ and Eu 3+ , and the tetragonal phase was 100% stabilized for 2 mol% of Tm 3+ and Tb 3+ . The structure of emission bands associated with Eu 3+ confirms the substitution of Zr 4+ 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 Eu 3+ , Tb 3+ and Tm 3+ , 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.