Multicolor Tuning in Room-Temperature Self-Activated Ca Nb O Submicroplates by Lanthanide Doping.

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 Ca Nb O was accordingly achieved in submicroplates synthesized using the sol-gel method. By further coupling the blue broadband emission from Ca Nb O submicroplates with the characteristic luminescence of Ln (Pr , Sm , and Dy ) dopants, multicolor emissions were successively tuned through adjusting the concentration of Ln . Our results are expected to expand the scope of designing room-temperature self-activated phosphors and tuning multicolor emission.