Yellow-orange upconversion emission in Eu(3+)-Yb(3+) codoped BaTiO(3) phosphor.

The Eu(3+)-Yb(3+) codoped BaTiO3 phosphor is prepared via co-precipitation method and its upconversion emission is studied by 980nm diode laser excitation. The X-ray diffraction pattern of the prepared sample showed the tetragonal BaTiO3 phase. The co-doped phosphor showed sharp upconversion emission bands peaking at ∼592, ∼614, ∼ 654, ∼704 and ∼796nm due to the (5)D0→(7)F1, (5)D0→(7)F2, (5)D0→(7)F3, (5)D0→(7)F4 and (5)D0→(7)F6 transitions, respectively of Eu(3+) ions. The sharp band at 489nm is assigned to the (2)F5/2→(2)F7/2 transition of Yb(3+) ion while the broad band around 505nm is assigned to the defect states present in the sample. Based on the available experimental data, the process involved in the UC emissions has been explored and elaborated.