Dy3+ 이온이 도핑된 Na3La(VO4)2 형광체의 합성과 분광학 연구

Abstract

Dy3+-doped Na3La(VO4)2 phosphors were synthesized by solid-state reaction method. The phase formation of the phosphors were confirmed by X-ray diffraction (XRD) analysis. Luminescence properties of the Na3La(VO4)2:Dy3+ phosphors are investigated from the emission and excitation spectra and decay curves measured at room temperature. The excitation spectra of the Na3La(VO4)2:Dy3+ phosphors exhibit absorption band due to the Dy3+ - O2- charge transfer transition in the wavelength region 200 ~ 350 nm and spectral lines due to the 4f – 4f transition in the 280 ~ 500 nm region. The excitation lines are observed at 352, 365, 387, 426, 451, 471 nm in which the strong excitation line at 365 nm due to the 6H15/2 → 4P7/2 transition. The emission lines are observed at 483, 574, 671, 691 nm in which the strongest line at 574 nm is due to the 4F9/2 → 6H13/2 transition. The decay time of the Dy3+ emission is estimated to be about 0.5 ms in the Na3La(VO4)2:Dy3+ phosphor. The luminescence intensity of the Na3La(VO4)2:Dy3+ phosphor increases linearly with Dy3+ concentration up to 10 mol%. This is attributed to the energy transfer between Dy3+ ions or from Dy3+ to quenching site.