Multicolor Tuning in Room-Temperature Self-Activated Ca2 Nb2 O7 Submicroplates by Lanthanide Doping

Abstract

Self-activated phosphors are capable of generating optical emissions from the internal ion groups of host lattice before externally introducing luminescent ions. However, numerous self-activated phosphors only show luminescence at low temperature due to the thermally activated energy migration among ion groups at room temperature, severely confining their application conditions. In this letter, we propose a strategy to converting the low-temperature luminescence to a room-temperature one through changing the synthesis conditions to induce structural distortions and thus to limit energy migration. Room-temperature self-activated luminescence of Ca₂ Nb₂ O₇ was accordingly achieved in submicroplates synthesized using the sol-gel method. By further coupling the blue broadband emission from Ca₂ Nb₂ O₇ submicroplates with the characteristic luminescence of Ln³⁺ (Pr³⁺ , Sm³⁺ , and Dy³⁺ ) dopants, multicolor emissions were successively tuned through adjusting the concentration of Ln³⁺ . Our results are expected to expand the scope of designing room-temperature self-activated phosphors and tuning multicolor emission.

Keywords: lanthanides; luminescence; multicolor; room temperature; self-activated.