Eu^(3+) 이온이 첨가된 YVO₄ 박막의 형광 동역학 특성

Abstract

Luminescence properties of Eu^(3+) ions in YVO4:Eu^(3+) thin film grown by the pulsed laser deposition (PLD) technique are investigated by site-selective laser-excitation spectroscopy in the temperature range of 17 K to room temperature. Time-integrated and time-resolved emission spectra were measured under the excitation at 266 nm from which the energy levels of Eu^(3+) in YVO₄ thin film could be assigned. The emission lines from the ^(5)D₃, ^(5)D₁, and ^(5)D_(0) states to the ^(7)F_(J) (J = 0, 1, 2, 3, 4) states are observed in the time-integrated spectrum. The time-resolved emission spectra were measured at 100 ns, 0.28 ㎲, and 40 ㎲ after the laser pulse. The broad emission due to the transition from the VO₄^(3-) exciton band of host YVO₄ thin film is observed only at time-resolved spectrum obtained at early time (100 ns). On the time-integrated emission spectrum at 0.28 ㎲ after the laser pulse, the broad band emission disappears and the emission lines from the ^(5)D₃ → ^(7)F_(J), 5D1 → ^(7)F_(J) and 5D 0→ ^(7)F_(J) transitions are dominant in the spectra. The time-integrated emission spectra at 40 ㎲ exhibit no emission peaks due to the ^(5)D₃ → ^(7)F_(J) and ^(5)D₁ → ^(7)F_(J) transitions, but strong peaks due to the ^(5)D_(0) → ^(7)F_(J) transitions. The mechanism of Eu^(3+) emission in YVO₄ thin film is discussed in relation with the interaction between Eu^(3+) and the YVO4 host lattice.