Cationic Effects on Photo- and X-ray Radioluminescence of KRE(PO):Ce/Pr (RE = La, Gd, and Y) Phosphors toward X-ray Detection.

Cationic tuning for lanthanide (Ce/Pr)-activated inorganic phosphors with stable, efficient, and fast-decay 5d-4f emissions has emerged as an important strategy toward the continuing pursuit of superior scintillators. The in-depth understanding of the cationic effects on photo- and radioluminescence of lanthanides Ce and Pr centers is requisite for the rational cationic tuning. Here, we perform a systematic study on the structure and photo- and X-ray radioluminescence properties of KRE(PO):Ce/Pr (RE = La, Gd, and Y) phosphors to elucidate the underlying cationic effects on their 4f-5d luminescence.

VUV-UV-vis photoluminescence, X-ray radioluminescence and energy transfer dynamics of Ce and Eu in SrMgSiO.

Ce and Eu doped and Ce-Eu co-doped SrMgSiO phosphors are prepared a high-temperature solid-state reaction technique. The synchrotron radiation vacuum ultraviolet-ultraviolet (VUV-UV) excitation and ultraviolet-visible (UV-vis) emission spectra of diluted Ce and Eu doped SrMgSiO samples are measured at cryogenic temperatures. The electron-vibrational interaction (EVI) between Ce and its surroundings is analyzed.

Shining Transparent Displays with Stable Narrow-Band Blue-Emitting Phosphor in Layered Film.

Transparent displays (TDs) rendering "levitating" images on screen have appeared as an emerging technology toward augmented/mixed reality applications. However, the traditional phosphor design and screen construction have severely limited the TD performance owing to the lack of efficient narrow-band blue emitters and stable screen structure. Herein, the novel narrow-band (full width at half maximum: 32 nm) NaLi SiO :Eu phosphor with a peak at 467 nm as a key blue emitter is explored, and it is sandwiched in layered film as a unique screen design.

Tunable Luminescence and Energy Transfer of SrBO:Ce, Sm Phosphors with Potential Anti-Counterfeiting Applications.

Sm and Ce singly doped and Sm and Ce co-doped SrBO phosphors are prepared via a high-temperature solid-state reaction method. The crystal structure and phase purity are characterized by X-ray diffraction (XRD) analyses. The Sm-doped sample displays an emission in the orange-red region, with the strongest emission line at about 648 nm and possessing a good luminescence thermal stability between 78 and 500 K.

Experimental and Theoretical Studies of the Site Occupancy and Luminescence of Ce in LiSr(BO) for Potential X-ray Detecting Applications.

Ce-doped LiSr(BO) phosphors have been prepared by a high-temperature solid-state reaction method, and structural refinement of the host compound has been performed. The excitation and emission spectra in the vacuum ultraviolet-ultraviolet-visible range at cryogenic temperatures reveal that Ce ions preferentially occupy eight-coordinated Sr sites in LiSr(BO). Such experimental attribution is well corroborated by the calculated 4f-5d transition energies and defect formation energies of Ce ions at two distinct Sr sites in the first-principles framework.

Site Occupancies, Electron-Vibration Interaction and Energy Transfer of CaMgSi O : Eu , Mn Phosphors for Potential Temperature-Sensing and Anti-counterfeiting Applications.

Eu -, Mn - and Eu -Mn -doped CaMgSi O phosphors have been prepared by a high-temperature solid-state reaction. Systematic investigation of the concentration- and temperature-dependent luminescence of Mn showed that Mn ions occupy two distinct sites in CaMgSi O . Electron-vibration interaction (EVI) analyses of Mn ions revealed Huang-Rhys factors of 4.

Structure, luminescence of Eu and Eu in CaMgSiO and their co-existence for the excitation-wavelength/temperature driven colour evolution.

Luminescent materials with controllable colour evolution features are demanded for the development of multi-level anti-counterfeiting technologies. Here we report the structural and luminescence properties of CaMgSi2O6:Ln (Ln = Eu2+, Eu3+, Eu2+/3+) samples in detail and reveal their excitation-wavelength/temperature driven colour evolution characteristics. By tuning either the excitation-wavelength (276, 304, 343, 394 nm) or temperature (in the 330-505 K range), the designed samples with co-existing Eu2+/Eu3+ ions can achieve diverse and controllable colour evolution from red, to pink, purple and blue.

Site Occupancies, VUV-UV-vis Photoluminescence, and X-ray Radioluminescence of Eu-Doped RbBaPO.

RbBaPO:Eu phosphors have been prepared by a high-temperature solid-state reaction method, and the structure was determined by Rietveld refinement based on powder X-ray diffraction (P-XRD) data. Their VUV-UV-vis photoluminescence properties are systematically investigated with three objectives: (1) based on low-temperature spectra, we clarify the site occupancies of Eu, and demonstrate that the doublet emission bands at ∼406 and ∼431 nm originate from Eu in Ba [Eu(I)] and Rb [Eu(II)] sites, respectively; (2) an electron-vibrational interaction (EVI) analysis is conducted to estimate the Huang-Rhys factors, the zero-phonon lines (ZPLs) and the Stokes shifts of Eu in Rb and Ba sites; (3) the studies on luminescence decay of Eu(I) reveal that dipole-dipole interaction is mainly responsible for the energy transfer from Eu(I) to Eu(II), and the energy migration between Eu(I) is weak. Finally, the X-ray excited luminescence (XEL) spectrum indicates that the light yield of the sample RbBaEuPO is ∼17 700 ph/MeV, showing its potential application in X-ray detecting.

The stability of coordination polyhedrons and distribution of europium ions in CaBaPO.

In this work, the coordination polyhedron stabilities and distributions of europium ions in Ca6BaP4O17 (CBPO) luminescent materials are investigated. The density functional theory (DFT)-based first principles calculation results show that the PO4 tetrahedrons can tilt in the structure, which leads to the atomic distortion of O13 and O12 in CBPO and the Eu2+/Eu3+-doped systems. The energy scale of about ∼0.

Host Differential Sensitization toward Color/Lifetime-Tuned Lanthanide Coordination Polymers for Optical Multiplexing.

Optical multiplexing based on luminescent materials with tunable color/lifetime has potential applications in information storage and security. However, the available tunable luminescent materials reported so far still suffer from several drawbacks of low efficiency or poor stability, thus restraining their further applications. Herein, we demonstrate a strategy to develop efficient and stable lanthanide coordination polymers (LCPs) with tunable luminescence as a new option for optical multiplexing.

Impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce in LiY(BO).

In this work, the crystal structure and electronic structure as well as the synchrotron radiation vacuum ultraviolet-ultraviolet-visible (VUV-UV-vis) luminescence properties of LiY(BO) (LYBO):Ce phosphors were investigated in detail. The Rietveld refinement and DFT calculation reveal the 2/ monoclinic crystal phase and the direct band gap of the LYBO compound, respectively. Only one kind of Ce 4f-5d transition is resolved in terms of the low temperature VUV-UV excitation, UV-vis emission spectra and luminescence decay curves.

Luminescence and Cationic-Size-Driven Site Selection of Eu and Ce Ions in CaMg(SiO)Cl.

In this work, the morphology, composition, crystal, and electronic structure of CaMg(SiO)Cl (CMSOC) prepared by a high-temperature solid-state reaction technique are characterized first. To investigate the site occupancies of Eu and Ce in CMSOC, the emission spectra under well-chosen wavelength excitations and the corresponding excitation spectra by monitoring of the specific wavelength emissions are measured in detail for singly doped samples with different concentrations. Two kinds of Eu or Ce luminescence spectra are found.

Concentration-Driven Selectivity of Energy Transfer Channels and Color Tunability in BaLa(PO):Tb, Sm for Warm White LEDs.

Here, we report the large-scale emission color tunability in BaLa(PO):Tb, Sm (BLPO:TS) system based on the detailed discussion on the concentration-driven selectivity of energy transfer (ET) channels from Tb to Sm. It is induced by the concentration-dependent D and D emissions of Tb and the different interaction mechanisms of ET from Tb to Sm via D and D channels. In the diluted Tb scenario, the red emission of Sm is efficiently sensitized via the D channel, while in the concentrated Tb case, the contribution of D channel is dominant.

Reversible immobilization of laccase onto metal-ion-chelated magnetic microspheres for bisphenol A removal.

Increasing attention has been given to nanobiocatalysis for commercial applications. In this study, laccase was reversibly immobilized onto Cu(ΙΙ)- and Mn(ΙΙ)-chelated magnetic microspheres and successfully applied to remove bisphenol A (BPA) from water. The results indicated that the loading of laccase onto the metal-ion-chelated magnetic microspheres was approximately 100mg/g.

Associations between variants on ADIPOQ and ADIPOR1 with colorectal cancer risk: a Chinese case-control study and updated meta-analysis.

Background: Epidemiological studies have suggested that variants on adiponectin (ADIPOQ) and its receptor ADIPOR1 (adiponectin receptor 1) are associated with colorectal cancer (CRC) risk; however, the results were inconclusive. The aim of the study was to evaluate the associations between the variants on ADIPOQ and ADIPOR1 and the CRC risk with a hospital-based case-control study in the Chinese population along with meta-analysis of available epidemiological studies.

Methods: With a hospital-based case-control study of 341 cases and 727 controls, the associations between the common variants on ADIPOQ (rs266729, rs822395, rs2241766 and rs1501299) and ADIPOR1 (rs1342387 and rs12733285) and CRC susceptibility were evaluated.

Association of variants on ADIPOQ and AdipoR1 and the prognosis of gastric cancer patients after gastrectomy treatment.

Adiponectin is a protein hormone secreted exclusively by adipocytes and it is responsible for insulin sensitization in the human body. Deregulation of adiponectin and its downstream signaling pathway genes have been found to be involved in the gastric cancer carcinogenesis; however, whether the variants on adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) affect the prognosis of gastric cancer patients are still unknown. Here we have recruited 455 gastric cancer patients, who have received the gastrectomy treatment to evaluate the prognostic effects of variants on ADIPOQ (rs266729 and rs822395) and AdipoR1 (rs12733285 and rs1342387) for the gastric cancer patients.

Selenium and colorectal adenomas risk: a meta-analysis.

Selenium, as an important component of some antioxidants, has been suggested to have protective effects against colorectal adenomas. This meta-analysis examined the association between selenium level in blood and risk of colorectal adenomas. Data from 7 studies (3 cross-sectional studies, 3 case-control studies, 1 nested case-control study) published before December 2011 was included in this meta-analysis.