YTaO_4:Gd,Eu体系光致发光中的能量传递

Energy Transfer in the Luminescence Process of YTaO_4:Gd,Eu

用高温固相反应法合成了钆、铕离子双掺杂的正钽酸盐化合物YTaO4 :Gd ,Eu ,研究了该体系在紫外光激发下的发光性能 .对该体系激发、发射及漫反射光谱的研究表明 ,Gd3+ 离子在发光过程中可以作为能量传递的中介 ,该体系在发光过程中存在钽酸根到Eu3+ 离子 ,或者钽酸根到Gd3+ 离子、再到Eu3+

Yttrium orthotantalate co doped by Eu 3+ and Gd 3+ has been synthesized by solid state method. The emission and excitation spectra of YTaO 4:Gd,Eu are studied in detail. In the excitation spectra of Eu 3+ 5D 0→ 7F 2 transition emission in YTaO 4:Gd,Eu,there appear excitations of Gd 3+ and TaO 3- 4 group, which indicate energy transfer from Gd 3+ and TaO 3- 4 group to Eu 3+ in the process of luminescence. The excitation spectra of Gd 3+ emission(λ=312 5 nm) including strong excitation of charge transfer of group show energy transfer from host lattice to Gd 3+ . So there are two ways of energy transfer in YTaO 4:Gd,Eu system. The strong evidences from excitation spectra, emission spectra and diffusive reflection spectra of this system show that Gd 3+ can play an intermediate role in the process of luminescence. There is energy transfer from TaO 3- 4 to Gd 3+ and finally to Eu 3+ via the charge transfer state and spectral overlap. The energy transfer from TaO 3- 4 to Gd 3+ is a dominating process in this system.