Multicolor Tuning in Room‐Temperature Self‐Activated Ca₂Nb₂O₇ 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 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.

Creating dual-mode luminescence in piezoelectric calcium niobates through lanthanide-doped for anti-counterfeiting and temperature sensing

“…1d. In this work, the experimental value of band gap of Ca2Nb2O7 is 3.99 eV which is similar with the previous reports [21]. In Fig.…”

“…Currently, the piezoelectric materials, mainly including piezoelectric crystal materials (such as LiNbO3 [16], GaPO4 [17]), bismuth layered piezoelectric ceramic materials (such as SrBi2Ta2O9 [18] and Bi4Ti3O12 [19]) and AnBnO3n+2 perovskite layered structures (PLS) (such as Sr2Nb2O7 [20], Ca2Nb2O7 [21]), have attracted more and more attentions due to their unique advantages. Among them, the PLS ferroelectric material with the general formula AnBnO3n+2 has important applications in the field of photochromic and multi-functional devices because of its high sensitivity and inherent piezoelectric characteristics [22,23].…”

Structures, photoluminescence, and principles of self-activated phosphors

“…(2) Charge transfer luminescence, which is common in groups consisting of an oxygen-surrounded central transition metal, including VO 4 3− , WO 4 2− , WO 6 6− , MoO 4 2− , TaO 3− , NbO 4 3− , and NbO 6 7− . 5 (3) Luminescence in all-inorganic semiconductors such as excitons and some defect-related luminescence. 6 Detail examples of each case are discussed in the next section.…”

Alkaline-earth-metal-ion blending enhanced mechanoluminescence of lanthanide ions in MZnOS hosts for stress sensing and anticounterfeiting

“…9 Recent ML investigations mainly deal with organic-complexes 10–13 and inorganic-crystal hosts. 14–18 Owing to the simplified synthetic method, 19 convenient post-processing steps and long-term storage stability of inorganic-crystal ML hosts compared to the organic-complex ML hosts, 1,12 inorganic-crystal ML hosts are being extensively explored and utilized to design novel ML materials, 20,21 such as oxonitridosilicates BaSi 2 O 2 N 2 , 22 niobates (Li, Na)NbO 3 , 15 (Ca, Sr) 2 Nb 2 O 7 , 23 aluminate SrAl 2 O 4 24,25 and quaternary oxysulfides (MZnOS, M = Ca, Sr, and Ba). 26–30…”