Host-sensitized luminescence in LaNbO4:Ln(3+) (Ln(3+) = Eu(3+)/Tb(3+)/Dy(3+)) with different emission colors

Recent progress in trivalent europium (Eu3+)-based inorganic phosphors for solid-state lighting: an overview

Narrow band red-emitting phosphors are significant constituents but still a bottleneck for next-generation smart displays and high-performance lighting (solid-state lighting based white light-emitting diodes (WLEDs)) technology. This review emphasizes the fundamental understanding and comprehensive overview of the recent progress and challenges associated with inorganic phosphors or down (wavelength) convertors, providing special attention to narrowband red-emitting oxide phosphors for phosphor-converted WLEDs (pc-WLEDs). In this context, the comprehensive progress on trivalent europium (Eu3+, in scheelite and double perovskite structures) based oxide phosphors with special emphasis on structure-composition-property-correlations is briefly reviewed. Furthermore, the challenges faced in the design of new oxide red phosphors and strategies to improve their absorption, emission efficiency, and future research direction are highlighted.

Photoluminescence behavior of rare earth doped self-activated phosphors (i.e. niobate and vanadate) and their applications

In the present study, the photoluminescence behaviors of rare earth doped self-activated phosphors are discussed briefly. Different techniques were used to develop these phosphor samples. We prepared pure and rare earth doped phosphor samples to look for their various applications. The structural confirmations and surface morphologies were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively. The upconversion (UC) phenomenon was investigated in Tm³⁺/Yb³⁺ and Ho³⁺/Yb³⁺ co-doped niobate and vanadate based phosphors, which gave intense blue/NIR and green/red emissions with a 980 nm diode laser as an excitation source. Pure niobate and vanadate phosphor materials are self-activated hosts which give broad blue emission under UV excitation. Upon UV excitation, intense broad blue emission along with sharp emissions due to Tm³⁺ and Ho³⁺ ions are observed via energy transfer between niobate/vanadate and rare earth ions. These self-activated hosts show prominent downshifting (DS) behavior. Broad band quantum cutting (QC) was observed in these self-activated hosts, in which a blue emitting photon is converted into two NIR photons by co-doping Yb³⁺ ions in it. The multimodal (upconversion, downshifting and quantum cutting) behaviors of these phosphors make them very promising in various applications, such as spectral converters to enhance the efficiency of a c-Si solar cell, security ink and color tunable materials.

Luminescent properties of neodymium, samarium and europium niobate and tantalate thin films

Thin films of lanthanide orthoniobate LnNbO₄ (LnNO) and orthotantalate LnTaO₄ (LnTO), (Ln = Nd, Sm, Eu) were fabricated by sol-gel method with subsequent spin-coating on PbZrO₃ /Al₂ O₃ substrate and annealing at 1000°C. X-ray diffraction patterns showed monoclinic M-LnNbO₄ or M´-LnTaO₄ , which coexists with orthorhombic or tetragonal phase. X-ray photoelectron spectroscopy demonstrate presence of Nd³⁺ , Sm³⁺ /Sm²⁺ and Eu³⁺ /Eu²⁺ ions. Luminescence properties of polymorphic films were investigated. Excitation spectra of PbZrO₃ interlayer represented broad bands at 410 and 550 nm, that were assigned to charge transfer bands (CTB). In all films, CTB broad band at around 275 nm related to charge transfer transition of Ln³⁺ → O^2- and NbO₄ ^3- or TaO₄ ^3- groups. In excitation spectra, ⁴ I_9/2 → ⁴ G_5/2 (Nd³⁺ ), ⁶ H_5/2 → ⁶ P_3/2 (Sm³⁺ ) and ⁷ F₀ → ⁵ L₆ (Eu³⁺ ) transitions (at 585, 402 and 395 nm), respectively are found to be more intense than any other Ln³⁺ transition. The emission spectra showed narrow and intense bands at 1065, 600 and 614 nm ascribed to Nd³⁺ , Sm³⁺ and Eu³⁺ 4f-f intraconfigurational transition ⁴ F_3/2 → ⁴ I_11/2 , ⁴ G_5/2 → ⁶ H_7/2 and ⁵ D₀ → ⁷ F₂ , respectively. The excellent luminescencent properties of films make them new potential group for visible and/or near-infrared applications such as sensors and imaging equipments.

Tuning Green to Red Color in Erbium Niobate Micro- and Nanoparticles

Tetragonal Er_0.5Nb_0.5O₂ and monoclinic ErNbO₄ micro- and nanoparticles were prepared by the citrate sol–gel method and heat-treated at temperatures between 700 and 1600 °C. ErNbO₄ revealed a spherical-shaped crystallite, whose size increased with heat treatment temperatures. To assess their optical properties at room temperature (RT), a thorough spectroscopic study was conducted. RT photoluminescence (PL) spectroscopy revealed that Er³⁺ optical activation was achieved in all samples. The photoluminescence spectra show the green/yellow ²H_11/2, ⁴S_3/2→⁴I_15/2 and red ⁴F_9/2→⁴I_15/2 intraionic transitions as the main visible recombination, with the number of the crystal field splitting Er³⁺ multiplets reflecting the ion site symmetry in the crystalline phases. PL excitation allows the identification of Er³⁺ high-energy excited multiplets as the preferential population paths of the emitting levels. Independently of the crystalline structure, the intensity ratio between the green/yellow and red intraionic transitions was found to be strongly sensitive to the excitation energy. After pumping the samples with a resonant excitation into the ⁴G_11/2 excited multiplet, a green/yellow transition stronger than the red one was observed, whereas the reverse occurred for higher excitation photon energies. Thus, a controllable selective excited tunable green to red color was achieved, which endows new opportunities for photonic and optoelectronic applications.

Tb-Doped core-shell-shell nanophosphors for enhanced X-ray induced luminescence and sensitization of radiodynamic therapy

The development of radiation responsive materials, such as nanoscintillators, enables a variety of exciting new theranostic applications. In particular, the ability of nanophosphors to serve as molecular imaging agents in novel modalities, such as X-ray luminescence computed tomography (XLCT), has gained significant interest recently. Here, we present a radioluminescent nanoplatform consisting of Tb-doped nanophosphors with an unique core/shell/shell (CSS) architecture for improved optical emission under X-ray excitation. Owing to the spatial confinement and separation of luminescent activators, these CSS nanophosphors exhibited bright optical luminescence upon irradiation. In addition to standard physiochemical characterization, these CSS nanophosphors were evaluated for their ability to serve as energy mediators in X-ray stimulated photodynamic therapy, also known as radiodynamic therapy (RDT), through attachment of a photosensitizer, rose bengal (RB). Furthermore, cRGD peptide was used as a model targeting agent against U87 MG glioblastoma cells. In vitro RDT efficacy studies suggested the RGD-CSS-RB in combination with X-ray irradiation could induce enhanced DNA damage and increased cell killing, while the nanoparticles alone are well tolerated. These studies support the utility of CSS nanophosphors and warrants their further development for theranostic applications.

Temperature dependence of up-conversion luminescence and sensing properties of LaNbO4: Nd3+/Yb3+/Ho3+ phosphor under 808 nm excitation

LaNbO₄: Nd³⁺/Yb³⁺/Ho³⁺ phosphor was prepared by a conventional high temperature solid-state reaction method. The temperature dependence of up-conversion (UC) luminescence property of LaNbO₄: Nd³⁺/Yb³⁺/Ho³⁺ phosphor under 808 nm excitation and the potential application of exploiting the red-to-green UC emission intensity ratio (I_R/I_G) of Ho³⁺ in temperature sensing were studied. Two-photon processes were confirmed to be responsible for both the green and the red UC emissions at different temperatures by analyzing the excitation power density dependent UC luminescence spectra measured at different temperatures. The energy level diagram was drawn to analyze the UC luminescence mechanism of Ho³⁺. In addition, it was found that the ratio I_R/I_G of Ho³⁺ was independent of the excitation power density of 808 nm laser under the current experimental condition, but it was sensitive to the temperature. And the temperature dependent UC luminescence spectra displayed that the ratio I_R/I_G exhibited a good linear increasing tendency with temperature rising. The obtained temperature sensing sensitivity was 2.04 × 10^-3 K^-1 in the temperature range of 303-693 K. The results suggest that LaNbO₄: Nd³⁺/Yb³⁺/Ho³⁺ phosphor may be a good candidate for application in optical temperature sensors.

Thermally robust and valence-variation-induced white-light emission of a novel stannate phosphor Sr3Al10SnO20:Dy3+: crystal structure, luminescence property, and mechanism investigation

The development of novel white-light-emission phosphors is of great importance for applications in lighting and display fields. Trivalent Dy3+ is widely used as a potential luminescence center for white-light emission. However, Dy3+-doped phosphors often suffer a poor yellow to blue ratio due to the deficiency of its 4F9/2 → 6H15/2 transition, low luminescence efficiency, and unsatisfactory thermal stability. The importance of the present research work is that we have achieved a tunable white light in a single phased stannate phosphor Sr3Al10SnO20:Dy3+ with robust thermal stability. The crystal structure, phase purity, and chemical composition were investigated via X-ray diffraction Rietveld structure refinement, scanning electron microscopy, and energy dispersive spectrometry. The luminescence spectra indicated that Sr3Al10SnO20:Dy3+ not only exhibited characteristic 4F9/2 → 6HJ/2 (J=11, 13, and 15) inherent transition emissions of Dy3+, but also showed an abnormal blue band emission, which was identified through X-ray photoelectric spectroscopy as the T1 → S0 transitions of Sn2+, resulting from the valence variation of Sn4+. The efficient energy transfer from Sn2+ to Dy3+ was also confirmed and the transfer efficiency was calculated. Owing to the valence-variation-induced emission of Sn2+, a tunable white light could be realized from a cool to warm white light region, with Commission Internationale de l'Eclairage coordinates and a correlative color temperature varying from (0.277, 0.333) and 8634 K to (0.353, 0.404) and 4913 K, respectively. The luminescent and defects formation mechanism as well as the luminescence kinetics were further investigated. Moreover, Sr3Al10SnO20:Dy3+ had a high quantum efficiency (∼34.6%) and a super-stable thermal stability behavior (82.5% at 240 °C of the initial integral emission intensity at 30 °C) with a large activation energy (ΔE ∼ 0.1654 eV). Finally, a charge-compensation test was performed to further verify the effect of defects on the luminescence property and the related mechanism was discussed. The current work provides a novel method to achieve tunable white-light emission in Dy3+ single-doped phosphors and the related mechanism is effectual for other rare earths for potential applications in lighting and display fields.

Broad-Band Excited and Tunable Luminescence of CaTbAl3O7:RE3+ (RE3+ = Ce3+ and/or Eu3+) Nanocrystalline Phosphors for Near-UV WLEDs

Here, we demonstrate a novel donor-intermediate-receptor energy transfer model through a Ce³⁺ → Tb³⁺ → Eu³⁺ scheme in a CaTbAl₃O₇:Ce³⁺,Eu³⁺ nanocrystalline phosphor. A new type of CaTbAl₃O₇ and CaTbAl₃O₇:RE³⁺ (RE³⁺ = Ce³⁺ and/or Eu³⁺) nanocrystalline phosphors were prepared by a simple sol-gel method. There exist efficient energy transfers of Ce³⁺ → Tb³⁺, Tb³⁺ → Eu³⁺, and Ce³⁺ → Tb³⁺ → Eu³⁺ in CaTbAl₃O₇:RE ³⁺ (RE ³⁺ = Ce³⁺ and/or Eu³⁺) nanocrystalline phosphors. With near-UV or UV light excitation, the as-prepared CaTbAl₃O₇:RE ³⁺ (RE ³⁺ = Ce³⁺ and/or Eu³⁺) nanocrystalline phosphors' luminous color can be regulated from green to green-yellow, yellow, orange, and orange-red by adjusting the doping concentration, categories, and different proportions of codoping Ce³⁺ to Eu³⁺ ions in the CaTbAl₃O₇ matrix. The luminescence mechanism with respect to the CaTbAl₃O₇:RE³⁺ (RE³⁺ = Ce³⁺ and/or Eu³⁺) nanocrystalline phosphors has been tentatively proposed. Due to their excellent luminescence properties, the as-prepared CaTbAl₃O₇, CaTbAl₃O₇:Ce³⁺, CaTbAl₃O₇:Eu³⁺, and CaTbAl₃O₇:Ce³⁺,Eu³⁺ nanocrystalline phosphors exhibit bright prospects in NUV-LEDs and other photoelectric field.

Multicolor tunable luminescence and energy transfer of core-shell structured SiO2@Gd2O3 microspheres co-activated with Dy3+/Eu3+ under single UV excitation

Optimizing structure and varying doped ions are two main strategies to obtain excellent luminescence performance. Spherical morphology is considered to be the most ideal phosphor structure due to the least surface defects. Herein, a series of spherical and monodispersed Dy³⁺/Eu³⁺ co-activated SiO₂@Gd₂O₃ core-shell phosphors with multicolor tunable luminescence were successfully prepared via a facile urea assisted precipitation method. Related chemical reactions and the possible growth mechanism of Gd₂O₃:Ln³⁺ directional deposition on the surface of SiO₂ microspheres were put forward. Upon 273 nm UV radiation excitation, SiO₂@Gd₂O₃:Dy³⁺ and SiO₂@Gd₂O₃:Eu³⁺ samples exhibited characteristic yellow (⁴F_9/2-⁶H_13/2) and blue (⁴F_9/2-⁶H_15/2) emissions of Dy³⁺ and red (⁵D₀-⁷F₂) emission of Eu³⁺, respectively. Meanwhile, multicolor emissions (warm white, yellow and orange) could be easily obtained by modulating the relative content of Dy³⁺ and Eu³⁺ in SiO₂@Gd₂O₃:Ln³⁺ samples under a single excitation wavelength. Moreover, it was confirmed that Dy³⁺ could transfer energy to Eu³⁺ in the form of quadrupole-quadrupole interaction and further improved the luminescence intensity of Eu³⁺ by comparing experimental data with theoretical calculations. These results imply that tunable luminescence Dy³⁺,Eu³⁺ co-doped SiO₂@Gd₂O₃ microspheres have great potential applications in multicolor displays and biolabeling fields.

Yellow Emission Obtained by Combination of Broadband Emission and Multi-Peak Emission in Garnet Structure Na2YMg2V3O12: Dy3+ Phosphor

The fabrication and luminescent performance of novel phosphors Na₂YMg₂V₃O₁₂:Dy³⁺ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na₂YMg₂V₃O₁₂ host self-activated and released a broad emission band (400-700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO₄)^3- groups. Meanwhile, the Na₂YMg₂V₃O₁₂:Dy³⁺ phosphors emitted bright yellow light within both the broad emission band of the (VO₄)^3- groups and the sharp peaks of the Dy³⁺ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na₂YMg₂V₃O₁₂:Dy³⁺ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y₂O₃:Eu³⁺ red phosphors, and BaMgAl₁₀O₁₇:Eu²⁺ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na₂YMg₂V₃O₁₂:Dy³⁺ phosphor as a yellow-emitting phosphor in solid-state illumination.

Constructing a tetraphenylethene (TPE) derivative-decorated polyvinyl alcohol (PVA)/lanthanide nanoparticle composite system for tunable luminescence

It is found for the first time that TPEBA-modified PVA ligand-coated lanthanide nanoparticles display tunable luminescent properties due to the established energy transfer from the TPE-based ligand (donor) to the lanthanide nanoparticles (acceptor).

Enhanced Photoluminescence Properties of Low-Dimensional Eu3+-Activated Y4Al2O9 Phosphor Compared to Bulk for Solid-State Lighting Applications and Latent Fingerprint Detection-Based Forensic Applications

In recent years, nanoscale phosphors have become vital in optoelectronic applications and to understand the improved performance of nanophosphors over bulk material, detailed investigation is essential. Herein, trivalent europium-activated Y4Al2O9 phosphors were developed by solid-state reaction and solvothermal reaction methods and their performance as a function of their dimension was studied for various applications. Under 394 nm optical excitation, the photoluminescence (PL) emission, excited state lifetime of the nanophosphor, exhibits greater performance than its bulk counterpart. The homogeneous spherical structure of the nanophosphors as compared with solid lumps of bulk phosphors is the basis for almost 40% of the enhancement in nanophosphors' intense red emission compared to the bulk. Moreover, the thermal stability of the nanophosphor is much better than the bulk phosphor, which clearly indicates a key advantage of nanophosphor. The superior performance of Eu3+-doped Y4Al2O9 nanophosphors over their bulk counterparts has been demonstrated for industrial phosphor-converted light-emitting diodes and visualization of latent fingerprint.

Investigation of Upconversion, downshifting and quantum -cutting behavior of Eu3+, Yb3+, Bi3+ co-doped LaNbO4 phosphor as a spectral conversion material

This work presents the spectral conversion characteristics [upconversion (UC), downshifting (DS) and quantum-cutting (QC) optical processes] of Eu³⁺, Yb³⁺ and Bi³⁺ co-doped LaNbO₄ (LBO) phosphor samples synthesized by solid state reaction technique. The crystal structure and the pure phase formation have been confirmed by x-ray diffraction (XRD) measurements. The surface morphology and particle size are studied by scanning electron microscopy (SEM). The rarely observed intense red UC emission from Eu³⁺ ion has been successfully obtained in Eu³⁺/Yb³⁺ co-doped LaNbO₄ phosphor (on excitation with 980 nm) by optimizing the concentrations of Eu³⁺ and Yb³⁺ ions. The downshifting (DS) behavior has been studied by photoluminescence (PL) measurements on excitation with 265 nm wavelength from a Xe lamp source. A broad blue emission in the region 300-550 nm with its maximum ∼415 nm due to charge transfer band (CTB) of the host and large number of sharp peaks due to f-f transitions of Eu³⁺ ion have been observed. The energy transfer has been observed from (NbO₄)^3- to Eu³⁺ ion and the fluorescence emission has been optimized by varying the concentration of Eu³⁺ ion. An intense red emission has also been observed corresponding to ⁵D₀ → ⁷F₂ transition of Eu³⁺ ion at 611 nm in LBO: 0.09Eu³⁺ phosphor on excitation with 394 nm. The luminescence properties of Eu³⁺ ion are enhanced further through the sensitization effect of Bi³⁺ ion. The near infra-red (NIR) quantum cutting (QC) behavior due to Yb³⁺ ion has been monitored on excitation with 265 as well as 394 nm. The NIR QC is observed due to ²F_5/2 → ²F_7/2 transition of Yb³⁺ ion via co-operative energy transfer (CET) process from (NbO₄)^3- as well as Eu³⁺ ions to Yb³⁺ ion. This multimodal behavior (UC, DS and QC) makes this a promising phosphor material for multi-purpose spectral converter.

Morphology control and photoluminescence properties of Eu3+-activated Y4Al2O9 nanophosphors for solid state lighting applications

Spherical Eu³⁺:Y₄Al₂O₉ nanophosphors exhibit brilliant PL behavior with enhanced color purity and excited state lifetime.

Assembly of 1D coaxial nanoribbons into 2D multicolor luminescence array membrane endowed with tunable anisotropic electrical conductivity and magnetism via electrospinning

A flexible 2D color-tunable coaxial nanoribbon array membrane with anisotropic electrical conductivity and magnetism is successfully fabricated via one-pot electrospinning.

Synthesis, structure and multicolor-tunable luminescence of the dandelion-like SiO2:Ln3+ (Ln = Eu, Tb) nanophosphors

Dandelion-like SiO₂:Ln³⁺ (Ln = Eu, Tb) nanophosphors of 70 nm diameter have been synthesized, and colorful emission phosphors were obtained by Ln³⁺ doping.

Tuning of luminescence properties by controlling an aid-sintering additive and composition in Na(Ba/Sr/Ca)PO4:Eu2+ for white LEDs

A series of Na(Ba/Sr/Ca)PO₄:Eu²⁺ phosphors were prepared via a high-temperature solid-state reaction method.

Enhanced anti-stocks luminescence in LaNbO4:Ln3+ (Ln3+ = Yb3+, Er3+/Ho3+/Tm3+) with abundant color

A 980 nm laser was employed to excite Yb³⁺ ions to achieve the 2F_7/2 → 2F_5/2 transition, and the LNO:Yb³⁺, Er³⁺/Ho³⁺/Tm³⁺ samples exhibited intense green, yellowish-green and blue emission, respectively.

Anomalous Orange Light-Emitting (Sr,Ba)2SiO4:Eu(2+) Phosphors for Warm White LEDs

Phosphors with sufficient red emission component are necessary for warm white light-emitting diodes. In this work on (Sr,Ba)2(1-x)Eu2xSiO4 phosphors, (Sr,Ba)1.5Eu0.5SiO4 achieved 75% of an internal quantum efficiency under excitation by blue light. Surprisingly, the (Sr,Ba)1.5Eu0.5SiO4 exhibited orange emission, against the well-known traditional green-yellow emission of (Sr,Ba)2SiO4:Eu(2+). Moreover, the concentration quenching of Eu(2+) in (Sr,Ba)2SiO4 was abnormally unobvious. With the help of calculations based on the density functional theory, it was discovered that the distinct local environment of luminescence centers rather than usual explanation such as self-absorption or intensified crystal field splitting, is responsible to the interesting red shifts in excitation and emission spectra. The refinement analysis based on X-ray diffraction revealed that the unequal distribution of Eu(2+) to two crystallographic sites caused low concentration of Eu(2+) at the 9-coordination site, inhibiting the concentration quenching. The (Sr,Ba)1.5Eu0.5SiO4 phosphor has warmer emission than the commercial Y3Al5O12:Ce(3+). This study also promotes research on the effect of site occupancy and the local environment of luminescence centers.

Doping Eu3+/Sm3+ into CaWO4:Tm3+, Dy3+ phosphors and their luminescence properties, tunable color and energy transfer

Eu³⁺ and Sm³⁺ co-doped CaWO₄:Tm³⁺, Dy³⁺ phosphors were prepared by a hydrothermal method. Under different UV radiations, the tunable color and warm-white-light emissions are realized.

Multi-color luminescence properties and energy transfer behaviour in host-sensitized CaWO4:Tb3+,Eu3+phosphors

A series of host-sensitized and color-tunable CaWO₄:Tb³⁺,Eu³⁺phosphors have been successfully synthesizedviathe high-temperature solid-state reaction route and their photoluminescence properties and energy transfer mechanism have been carefully investigated.

Facile hydrothermal synthesis and multicolor-tunable luminescence of YPO4:Ln3+ (Ln = Eu, Tb)

This work investigates a novel facile hydrothermal conversion method for the synthesis of uniform cuboid YPO₄ and obtains multicolor emissions in YPO₄:Tb³⁺, Eu³⁺ samples, and the energy transfer efficiency reachs about 94.30%.

Multifunctional luminescent nanomaterials from NaLa(MoO4)2:Eu(3+)/Tb(3+) with tunable decay lifetimes, emission colors, and enhanced cell viability

A facile, but effective, method has been developed for large-scale preparation of NaLa(MoO4)2 nanorods and microflowers co-doped with Eu(3+) and Tb(3+) ions (abbreviated as: NLM:Ln(3+)). The as-synthesized nanomaterials possess a pure tetragonal phase with variable morphologies from shuttle-like nanorods to microflowers by controlling the reaction temperature and the amount of ethylene glycol used. Consequently, the resulting nanomaterials exhibit superb luminescent emissions over the visible region from red through yellow to green by simply changing the relative doping ratios of Eu(3+) to Tb(3+) ions. Biocompatibility study indicates that the addition of NLM:Ln(3+) nanomaterials can stimulate the growth of normal human retinal pigment epithelium (ARPE-19) cells. Therefore, the newly-developed NaLa(MoO4)2 nanomaterials hold potentials for a wide range of multifunctional applications, including bioimaging, security protection, optical display, optoelectronics for information storage, and cell stimulation.

Tunable white-light emission via energy transfer in single-phase LiGd(WO4)2:Re3+ (Re = Tm, Tb, Dy, Eu) phosphors for UV-excited WLEDs

Novel single-phase white-light-emitting phosphors have been successfully synthesized by a solid-state reaction and their photoluminescence properties and energy transfer mechanism have been carefully investigated.

Energy transfer dynamics and luminescence properties of Eu3+ in CaMoO4 and SrMoO4

Undoped and europium doped CaMoO₄ and SrMoO₄ scheelites are synthesized using a complex polymerization method.

Dual-enhancement of photoluminescence and cathodoluminescence in Eu3+-activated SrMoO4 phosphors by Na+ doping

Energy level diagram of Eu³⁺ ions as well as possible PL mechanism in Eu³⁺-activated SrMoO₄ phosphors. PL spectra of Sr_0.93−yMoO₄:0.07Eu³⁺/yNa⁺ phosphors excited at 290 nm.

A new single-phase white-light-emitting CaWO4:Dy3+ phosphor: synthesis, luminescence and energy transfer

A new single-phase white-emitting CaWO₄:Dy³⁺ phosphor has been successfully synthesized and the photoluminescence properties and energy-transfer mechanism have been carefully investigated.