화학공학소재연구정보센터
Materials Chemistry and Physics, Vol.162, 801-806, 2015
Red-orange photoluminescence and dielectric relaxation of Eu3+-doped Bi2Ti2O7 pyrochlore structure thin films
Eu3+-doped Bi2Ti2O7 pyrochlore structure thin films were prepared by a chemical solution deposition method. The red-orange photoluminescence and dielectric relaxation of Bi2-xEuxTi2O7 thin films have been investigated in terms of Eu3+ doping content (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6) and annealing temperature. The crystallinity and surface morphology of the thin films were evaluated by X-ray diffractometer and field emission scanning electron microscopy. It was shown that the thin films annealed at 600 degrees C were well crystallized in pyrochlore structure without other impurity phases. Intense visible red-orange photoluminescence, originated from doubly split electric-dipole D-5(0) -> F-7(2) and magnetic-dipole D-5(0) -> F-7(1) transitions of Eu3+ ions, could be observed under ultraviolet excitation. The quenching concentration for photoluminescence of Bi2-xEuxTi2O7 thin films is about x = 0.5. In addition, the Bi2-xEuxTi2O7 thin films had a relatively low dielectric loss and a high dielectric constant as well as highly stable bias electric field properties. Meanwhile, the thin films exhibited dielectric relaxation based on the temperature and frequency dependence of dielectric properties. Our study suggested that Eu3+-doped Bi2Ti2O7 thin films have potential applications in new multifunctional optoelectronic thin-film devices. (C) 2015 Elsevier B.V. All rights reserved.