White- and blue-light-emitting dysprosium(III) and terbium(III)-doped gadolinium titanate phosphors

Here we report the synthesis and structural, morphological, and photoluminescence analysis of white- and blue-light-emitting Dy³⁺ - and Tm³⁺ -doped Gd₂ Ti₂ O₇ nanophosphors. Single-phase cubic Gd₂ Ti₂ O₇ nanopowders consist of compact, dense aggregates of nanoparticles with an average size of ~25 nm for Dy³⁺ -doped and ~50 nm for Tm³⁺ -doped samples. The photoluminescence results indicated that ultraviolet (UV) light excitation of the Dy³⁺ -doped sample resulted in direct generation of white light, while a dominant yellow emission was obtained under blue-light excitation. Intense blue light was obtained for Tm³⁺ -doped Gd₂ Ti₂ O₇ under UV excitation suggesting that this material could be used as a blue phosphor.