Power-dependent upconversion luminescence properties of self-sensitized Er2WO6 phosphor

A Yb³⁺ free self-sensitized Er₂WO₆ phosphor has been synthesized via a solid-state reaction method. The phosphor material, Er₂WO₆, has a monoclinic crystal structure with space group P2/c (13). The deconvoluted high-resolution X-ray photoelectron spectra of all the core elements in the Er₂WO₆ phosphor material were explored. The highly resolved absorption peaks in the ultra-violet, visible and near-infra-red (NIR) regions of the diffuse reflectance spectrum were due to the Stark-splitting of the 4f energy levels of the Er³⁺ ions. Under 980 nm NIR laser excitation, the Er₂WO₆ phosphor showed an intense up-converted red emission at 677 nm due to the ⁴F_9/2→⁴I_15/2 transitions of the Er³⁺ ions. The cross-relaxation and resonance energy transfer process involved in the key intermediate ⁴F_3/2 and ⁴F_5/2 levels of the Er³⁺ and their role in generating red emissions were investigated. The laser pump power versus upconversion intensity plot showed a slope with an n value <1 and the possible reasons behind this behavior were investigated. The photoluminescence properties of the Er₂WO₆ phosphor in the visible and NIR region were further analyzed. The potential application of the phosphor as a marker in latent fingerprint detection was also evaluated.

Hydrothermal synthesis and tunable up-conversion white luminescence properties of KSc(MoO4)2:Ln3+(Ln = Yb, Er, Tm and Ho) crystals

Pure hexagonal phase KSc(MoO₄)₂crystals with a hexagonal block shape were successfully synthesizedviaa one-step hydrothermal method.

Room-temperature ultrafast synthesis, morphology and upconversion luminescence of K0.3Bi0.7F2.4:Yb3+/Er3+ nanoparticles for temperature-sensing application

This manuscript describes an ultrafast route at room temperature for the synthesis of the K_0.3Bi_0.7F_2.4 nanoparticles with photoluminescence and luminescent temperature sensing.

Temperature-induced isostructural phase transition on NaCe(MoO4)2 system: A Raman scattering study

Temperature-dependent Raman spectroscopic study has been performed on scheelite-type sodium‑cerium molybdate - NaCe(MoO₄)₂ - in the temperature range 113-873 K. This study provides phonon properties of NaCe(MoO₄)₂, which are very important to understand the mechanism governing eventual phase transitions undergone by the structure, since phonons are very sensitive to structural changes. The ambient scheelite phase remains stable in a low-temperature range (113-293 K), and no relevant modification is observed in the Raman spectra. However, the experiments reveal the existence of one reversible phase transition at high-temperature. The vibrational spectra of NaCe(MoO₄)₂ system showed anomalies above 748 K, where overlaps of some bands and the appearance of a band at 458 cm^-1 are observed. These modifications were attributed to an isostructural phase transition and a discussion about the possible mechanism of this transformation is furnished.

Hydrothermal synthesis, characterization and luminescence properties of CaGd2(MoO4)4:Eu3+ ovoid like structures

Red light emission from CaGd₂(MoO₄)₄:0.06Eu³⁺ phosphor by EDTA assisted hydrothermal route at 200 °C for 24 h.

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO2-coated lanthanide-doped NaYF4 nanoconstructs

Multicolor upconversion of SiO₂-coated nanoparticles using for cells imaging and reactive oxygen species generation.

Facile hydrothermal synthesis and pulsed laser deposition of Ca0.5Y1−x(WO4)2:xEu3+ phosphors: investigations on the luminescence, Judd–Ofelt analysis and charge compensation mechanism

PL emission spectra of Ca_0.5Y_1−x(WO₄)₂:xEu³⁺ for powder and thin film phosphors, and PL spectra of Ca_0.5Y_1−x(WO₄)₂:xEu³⁺ co-doped with alkali metal ions.

Tunable photoluminescence and magnetic properties of Dy(3+) and Eu(3+) doped GdVO4 multifunctional phosphors

A series of Dy(3+) or/and Eu(3+) doped GdVO4 phosphors were successfully prepared by a simple hydrothermal method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrometry (EDS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). The results indicate that the as-prepared samples are pure tetragonal phase GdVO4, taking on nanoparticles with an average size of 45 nm. Under ultraviolet (UV) light excitation, the individual Dy(3+) or Eu(3+) ion activated GdVO4 phosphors exhibit excellent emission properties in their respective regions. The mechanism of energy transfer from the VO4(3-) group and the charge transfer band (CTB) to Dy(3+) and Eu(3+) ions is proposed. Color-tunable emissions in GdVO4:Dy(3+),Eu(3+) phosphors are realized through adopting different excitation wavelengths or adjusting the appropriate concentration of Dy(3+) and Eu(3+) when excited by a single excitation wavelength. In addition, the as-prepared samples show paramagnetic properties at room temperature. This kind of multifunctional color-tunable phosphor has great potential applications in the fields of photoelectronic devices and biomedical sciences.

Effect of co-doping of alkali metal ions on Ca0.5RE1−x(MoO4)2:xEu3+ (RE = Y, La) phosphors with enhanced luminescence properties

Illustration of elemental mapping and PL emission spectra of the phosphors, Ca_0.5RE_1−x(MoO₄)₂:Eu³⁺,M⁺ (RE = Y, La; M = Li, K and Na).

Dual-mode, tunable color, enhanced upconversion luminescence and magnetism of multifunctional BaGdF5:Ln3+ (Ln = Yb/Er/Eu) nanophosphors

BaGdF₅:Yb³⁺,Er³⁺/Eu³⁺ nanophosphors were prepared by a hydrothermal method, and the energy transfer, color-tunable dual-mode emissions and magnetic properties were studied, which could have promising applications in the fields of LEDs, MRI, biolabels, and so on.

One-step hydrothermal synthesis of Sc2Mo3O12:Ln3+ (Ln = Eu, Tb, Dy, Tb/Eu, Dy/Eu) nanosheets and their multicolor tunable luminescence

The energy transfer of MoO₄²⁻ → Tb³⁺ (Dy³⁺) → Eu³⁺ and multicolor tunable emission occurred in Sc₂Mo₃O₁₂ nanosheets prepared by one-step hydrothermal synthesis.

Morphology control and multicolor-tunable luminescence of YOF:Ln3+ (Ln = Eu, Tb, Dy, Tm) nano-/microcrystals

Multiform YOF nano-/microcrystals have been synthesized and multicolor-tunable luminescence of YOF:Ln³⁺ (Ln = Eu, Tb, Dy, Tm, Tm/Dy) has been investigated.

Phase transition, morphology transformation and highly enhanced luminescence properties of YOF:Eu3+ crystals by Gd3+ doping

We report the crystal phase transition, morphology transformation, and greatly enhanced luminescence properties of YOF crystals by Gd³⁺ doping.

Facile morphology-controllable hydrothermal synthesis and color tunable luminescence properties of NaGd(MoO4)2:Eu3+,Tb3+ microcrystals

Morphological control, formation mechanism and tunable photoluminescence of NaGd(MoO₄)₂:Eu³⁺,Tb³⁺ microcrystals synthesized by a facile hydrothermal method.

Up/down conversion, tunable photoluminescence and energy transfer properties of NaLa(WO4)2:Er3+,Eu3+ phosphors

A series of novel, color-tunable, single-component NaLa(WO₄)₂:Er³⁺,Eu³⁺ phosphors were prepared by a one-step hydrothermal method. The energy transfer mechanism was studied, and color-tunable emissions in NaLa(WO₄)₂ are realized.

Luminescent single molecule magnets of a series of β-diketone dysprosium complexes

A series of three β-diketone mononuclear Dy(iii) complexes exhibit bifunctional properties of single molecule magnet and luminescence.

Mechanistic investigation on up and down conversion of Er3+ and Gd3+ co-doped YTiNbO6 phosphors

The present work focuses on the up and down conversion of YNbTiO₆ with different quenching concentrations of Er³⁺ and Gd³⁺ as well as the energy transfer processes.

Synthesis and up/down conversion luminescence properties of Na0.5R0.5MoO4:Ln3+ (R3+ = La, Gd), (Ln3+ = Eu, Tb, Dy, Yb/Er) thin phosphor films grown by pulsed laser deposition technique

(Na_0.5R_0.5)MoO₄:Ln³⁺ thin phosphor films can serve as an excellent material for electro/cathodo-luminescence and display applications.