Luminescence properties of Eu3+, Tb3+ or Tm3+ activated Ca4GdO(BO3)3 under X-ray and UV excitation

Abstract

The X-ray and UV excited luminescence properties of Eu 3+ , Tb 3+ and Tm 3+ ions in the matrix of Ca 4 GdO(BO 3 ) 3 were investigated. Eu 3+ and Tb 3+ ions show high luminescence efficiency in emitting red and green color light for both under X-ray and UV excitation, respectively, while Tm 3+ ion did not show high luminescence efficiency in emitting blue color light. The energy transfer from Gd 3+ ion to Eu 3+ or Tb 3+ ion occurred for both under X-ray and UV excitation, while energy transfer from the Gd 3+ ion to Tm 3+ ion did not happen. The absorption spectra of Ca 4 GdO(BO 3 ) 3 :RE (RE = Eu 3+ , Tb 3+ and Tm 3+ ) were studied, the host lattice related absorption band was located at 211 nm, the CT absorption band of Eu 3+ ion and 4f → 5d transition absorption band of Tb 3+ ion were both located at 258 nm.