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Abstract: A novel red luminescent material Li0.9Y0.9Zr0.1O2 doped with trivalent europium ions and dysprosium ions was synthesized by solution–combustion method. X-ray diffractometry, transmission electron microscopy and optical spectroscopy were used to valuate the crystallinity, the morphological characterization and the optical properties of the products. The results showed that combustion at 800°C was enough to obtain highly crystalline and phase-pure samples. Photoluminescence spectra of Li0.9Y(0.9−x−y)Zr0.1O2:Eu x 3+,Dy y 3+ samples indicated the dominant red emissions (613nm) at a single-wavelength ultraviolet excitation (395nm) due to 5D0 → 7F2 transition. The relation between the luminescence intensity and dopant concentration was also discussed. [Copyright &y& Elsevier]

Abstract: Three-dimensional reticular-structured luminescence SrAl2O4:Eu,Dy powders were prepared by refluxing- and sonication-combustion synthesis without using any surfactant for the first time and were characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy. All the samples have a very porous, open and spongelike morphology with fractal properties. The excitation and emission spectra of the products have been measured by Edinburgh FLS920 at room temperature. The new formation-mechanism of the three-dimensional reticular-structure was proposed in this article. [Copyright &y& Elsevier]

Abstract: Pure and Mn-doped SrNb2O6 nanoparticles have been prepared by sol–gel combustion method using citric acid as fuel and complexing agent and nitrates as oxidants at a relatively low temperature compared to solid-state reaction method. X-ray diffraction (XRD) patterns of the pure SrNb2O6 samples show that the SrNb2O6 nanoparticles exhibited orthorhombic phase. Photoluminescence (PL) properties of all the undoped and Mn-doped samples were studied in detail. For the pure SrNb2O6 samples, a strong blue emission band centered at 442nm and two weak emission bands centered at 524nm and 626nm, respectively, can be observed. For the Mn-doped SrNb2O6 samples, no emission from Mn2+ was observed while the blue emission intensity of SrNb2O6 varied with the Mn-doping concentration. This novel PL characteristic of the doped samples was explained. [Copyright &y& Elsevier]

Abstract: A new red emitting phosphor, Ca3(VO4)2:Eu3+; Mn2+, was synthesized by a citric acid sol–gel combustion method and characterized by XRD, TEM and photoluminescence (PL) spectra. The red emission located at about 613nm was ascribed to 5D0–7F2 transition of Eu3+. And the red luminescence intensity changed with annealing temperature and concentration of Eu3+. The effect of the co-doped Mn2+ was also investigated systematically. [Copyright &y& Elsevier]

Abstract: Pure and Dy3+-doped Zn2SnO4 (ZTO) hollow spheres, integrated with nanoparticles, have been synthesized using the coprecipitation method. The ZTO spheres have been characterized with X-ray diffraction and scanning electron microscope. The photoluminescence and photocatalytic properties are investigated. The influences of Dy3+ ions on the morphology and the photoluminescence of ZTO have been explained in detail. [Copyright &y& Elsevier]

Abstract: Pure and Dy3+-doped NiNb2O6 nanoparticles have been prepared by a sol–gel combustion method using citric acid as fuel and complexing agent and nitrates as oxidants at a relatively low temperature compared to solid-state reaction method. The photoluminescence properties of these NiNb2O6 nanoparticles were studied in detail. For the pure NiNb2O6 nanoparticles, a blue emission band centered at 445nm is observed. For NiNb2O6:Dy3+ nanoparticles, no characteristic luminescence of Dy3+ can be observed while the host blue emission enhances. It is suggested that energy transfer from Dy3+ to niobate groups maybe occurs. [Copyright &y& Elsevier]

Abstract: Eu2+, R3+ co-doped alkaline earth aluminates MAl2O4: Eu2+, R3+ (M=Sr, Ba and Ca; R=Dy, Nd and La) nanoparticles with high brightness and long afterglow have been prepared by solution-combustion synthesis at 600°C without a post-annealing process for the first time. The morphologies and the phase structures of the products have been characterized by transmission electron microscopy and X-ray diffraction. The excitation and emission spectra of the products have been measured by an Edinburgh FLS920 spectrometer at room temperature. The characteristic luminescence of the as-prepared sample has been evaluated, and the reason why the wavelength changed from yellow-green to blue-green and then to blue-purple in visible range when the composition changed from SrAl2O4: Eu2+, Dy3+ to BaAl2O4: Eu2+, Nd3+ and then to CaAl2O4: Eu2+, La3+ has been explained. Furthermore, a new persistent luminescence mechanism was proposed in this article. [Copyright &y& Elsevier]

Abstract: Strontium stannate (SrSnO3) nanocrystals have been synthesized by using an efficient combustion method for the first time. The corresponding nanorods integrated with nanoparticles are also obtained with the coprecipitation method. X-ray diffraction, transmission electron micrograph and scanning transmission electron micrograph are used to illustrate the crystal structure, phase purity and morphology of the synthesized nanocrystals. The growth mechanisms are investigated in detail. [Copyright &y& Elsevier]

Abstract: V2O5 macro-plates have been prepared using water/ethanol media. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The as-prepared V2O5 plates appear to be an orthorhombic structure, and they seem to be composed of strip-like V2O5 nanocrystals which appear to be parallel or perpendicular to each other. The band gap of the V2O5 macro-plates calculated from the optical absorption edge is about 3.4 eV, showing a strong blue shift compared to bulk V2O5. It is also found that the final shape of the V2O5 macro-plates strongly depends on the reaction conditions. The possible formation mechanism of the V2O5 macro-plates is discussed. [Copyright &y& Elsevier]

Some of the metal vanadates have special self-activated luminescence. In order to further enrich its luminous color, luminescent impurity ions can be introduced into its lattice. The interaction between the self-activated emission and the impurity-related emission remains to be studied. In this work, the synergism between the two kinds of emission in LiCa 3 ZnV 3 O 12 was explored from these three aspects: lattice distortion, energy transfer and temperature effect. Eu 3+ ions replace Ca 2+ ions in the lattice of LiCa 3 ZnV 3 O 12 , leading to a lattice contraction of the LCZV host, which depresses the self-activating emission around 500 nm. The characteristic linear emissions of Eu 3+ ions are also observed benefiting from the energy transfer from [VO 4 ] 3- to Eu 3+ . Since the temperature quenching effect is more sensitive for the self-activated emission than that for the Eu 3+ -related ones, the phosphor can be applied as a luminescent temperature sensor, with the absolute and relative temperature sensitivities of 0.012 K -1 and 1.56% K -1 , respectively., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The stability of metal halide perovskite (CsPbX 3 , X = Cl, Br, and I) nanocrystals (NCs) is crucial for their practical applications. In this paper, perovskite NCs were synthesized in situ in lead-based metal-organic frameworks (Pb-MOFs: [Pb 2 (1,3,5-HBTC) 2 (H 2 O) 4 ]·H 2 O), and we obtained stable and bright luminescence composites with different colors. Namely, CsPbBr 3 @Pb-MOF composites were created by the in situ growth of CsPbBr 3 crystals (NCs) on Pb-MOF, which had high ion resistance, bright photoluminescence (PL), and excellent stability. The composites still had bright luminescence after 11 months of storage. The PL intensity of green-emitting CsPbBr 3 @Pb-MOF composites was increased compared with as-prepared CsPbBr 3 NCs. Bright and stable blue- and red-emitting CsPbX 3 @Pb-MOF composites were obtained by adjusting the amount of PbX 2 (X = Cl, Br, and I) in the synthesis process. These CsPbX 3 NCs were homogeneously distributed in Pb-MOF substrates. The growth of CsPbX 3 NCs in Pb-MOFs prevented NC aggregation and decreased surface defects against nonradiative recombination during emitting. Thus, the PL lifetime and stability were improved. Furthermore, white light-emission diodes were prepared using three color CsPbX 3 @Pb-MOF composites with Commission Internationale de I'Eclairage color coordinates of (0.296, 0.316). This result provided an efficient way to overcome the limitation of chemical solution synthesis and improve the stability of CsPbX 3 NCs.

TGA capped CdTe QDs have been encapsulated in miroporous ZIF-8, with no obvious deterioration of their photoluminescence property. The resulted CdTe QD@ZIF-8 composites show a higher luminescent stability in various buffer solution. The material has successfully been used as a luminescent indicator for the detection of Cu 2+ and Fe 2+ ions. The luminescence of CdTe QD@ZIF-8 composite quenches only in the presence of Cu 2+ or Fe 2+ ions. The linear ranges of detection have been estimated as 1~50 uM for Cu 2+ ions and 1~60 uM for Fe 2+ ions, respectively. A "competing transmission" mechanism has been proposed to explain the selectivity of the sensor to detecting Cu 2+ and Fe 2+ ions. Luminescent quenching can only occurred when the bonding power of QD surface surpasses the adsorptivity of the outside ZIF-8 to the metal ions.

In this study, a series of LaNbTiO6:RE(3+) (RE = Tb, Dy, Ho) down-converting phosphors were synthesized using a modified sol-gel combustion method, and their photoluminescence (PL) properties were investigated as a function of activator concentration and annealing temperature. The resultant particles were characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, UV/Vis diffuse reflectance spectroscopy and PL spectra. The highly crystalline LaNbTiO6:RE(3+) (RE = Tb, Dy, Ho) phosphors with an average size of 200-300 nm obtained at 1100°C have an orthorhombic aeschynite-type structure and exhibit the highest luminescent intensity in our study range. The emission spectra of LaNbTiO6:RE(3+) (RE = Tb, Dy, Ho) phosphors under excitations at UV/blue sources are mainly composed of characteristic peaks arising from the f-f transitions of RE(3+), including 489 nm ((5) D4 → (7) F6) and 545 nm ((5) D4 → (7) F5) for Tb(3+), 476 and 482 nm ((4) F9/2 → (6) H15/2) and 571 nm ((4) F9/2 → (6) H13/2) for Dy(3+), and 545 nm ((5) F4 + (5) S2 → (5) I8) for Ho(3+), respectively. The luminescent mechanisms were further investigated. It can be expected that these phosphors are of intense interest and potential importance for many optical applications., (Copyright © 2013 John Wiley & Sons, Ltd.)

Novel Li(0.9)Y((0.9-x-y))Zr(0.1)O(2):Eu(x)(3+), R(y)(3+) (R = Ce,Bi) red nanocrystal phosphors were synthesized by the sol-combustion process at 800 degrees C. XRD and TEM were used to evaluate the crystallinity and the morphological characterization of the samples. The photoluminescence properties and lifetime of the obtained phosphor nanoparticles were measured using an Edinburgh FLS920 at room temperature. The result showed that the luminescence intensity of Li(0.9)Y((0.9-x-y))Zr(0.1)O(2):Eu(x)(3+) was increased by Bi(3+) and Ce(3+) by 900% and 600%, respectively. The emission mechanism and sensitization mechanism of Bi(3+) and Ce(3+) on Eu(3+) emission intensity were described and explained in detail in this work. The high bright and color-uniform fluorescence images of the doped samples with short luminescence decay times (nanosecond level) confirmed the potential applications of the phosphors in light-emitting diodes and display devices.