Trivalent Erbium Ions Research Articles

Bimolybdate single crystals codoping with trivalent ytterbium and erbium ions for high-stable and high-sensitive optical thermometry

Replacing conventional powder polycrystalline materials with crystalline materials is an effective strategy to improve the sensing sensitivity, responsiveness, and anti-interference capabilities of the fluorescence intensity ratio (FIR) based optical temperature sensing techniques. In this work, Yb3+/Er3+ codoped bimolybdate single crystals, NaBi(MoO4)2 (NBM) with different Er3+ ion doping concentrations, were grown by the Czochralski method, in which is expected to be used for optical temperature sensing applications. The structure of the crystals was fully characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and transmission electron microscopy (TEM). Under 980 nm laser excitation, the crystals demonstrated notable green and slight red upconversion (UC) emissions, and the mechanism of UC luminescence was thoroughly investigated. The luminescence intensity was found to be contingent upon the doping concentration, which gradually decayed with increase of Er3+ ions. The optical temperature sensing performance of Yb3+/Er3+ codoped NBM single crystals was evaluated by the FIR technique based on the thermally coupled level of Er3+ ions (2H11/2/4S3/2). The experimental findings revealed that the 10 at% Yb3+, 10 at% Er3+: NBM crystal exhibited highest sensor sensitivity among the synthesized crystals, with a maximum absolute sensitivity of approximately 1.22 % K−1 at 510 K. Furthermore, the temperature sensing characteristics of the crystals appeared to be dependent on the doping concentration of Er3+ ions. In summary, the Yb3+/Er3+ codoped NBM single crystal showcased excellent sensor sensitivity and held considerable promise as materials for optical temperature sensing applications.

Expanding the Toolbox for Industrial Luminescent Primary Thermometry: Er3+-doped SrMoO4

We herein demonstrate the feasibility of employing strontium molybdate as host matrix for trivalent erbium ions for the developing of an optical temperature sensor operating in a wide temperature range suitable for industrial applications. This class of metal molybdate, known for its chemical and thermal capabilities, works as primary luminescent thermometer, relying on the thermally coupled levels of Er3+ arising from downshifting processes, neglecting first, the requirement of calibration curve acquisition and second, the excitation induced heating on the sample typically observed in upconverting luminescent thermometers. The synthesised primary optical thermometer displays a maximum temperature relative sensitivity of 1.13 %. K−1 and minimum temperature uncertainty and 0.09 K. These values make the performance of the Er3+-doped strontium molybdate as optical temperature sensor competitive with the existing luminescent primary thermometers, including a wide operating temperature range up to 413 K and high accuracy as main features. Moreover, it can be easily scaled up and produced due to straightforwardness and cost-effectiveness of the ceramic synthesis method, matching the requirements for its usage in industrial environments.

Synthesis, structural, and optical behavior of erbium-doped silicophosphate glasses for photonics applications.

Erbium-incorporated silicophosphate glasses are very desirable in principal sectors such as photonics, optoelectronics, lasers, and illuminating diodes. The focus of the current investigation has been on determining how the erbium dopant affects the optical, physical, and structural characteristics of the silicophosphate-based glasses. The pure silicophosphate glasses and doped with various contents of erbium were prepared by the sol-gel process in this work. The noncrystalline character of the glasses synthesized was confirmed by the XRD patterns that were obtained. The optical measurement showed that the addition of trivalent erbium ions resulted in an increase in the refractive index of the samples and a decrease in their energy band gap values. It demonstrated the presence of P-O-P linkage stretching vibration modes that were both symmetrical and asymmetrical, P-O in PO4 bending vibration modes, OH group elongating and flexure vibrations, and P-O-H water absorption in glasses. The theoretical values of the optical basicity (Ʌth) increased from 0.465 to 0.472, while the values of the interaction parameter (A) decreased from 0.218 to 0.214 . Silicophosphate glasses doped with trivalent erbium ions show promise as optoelectronic and optical filter system materials.

Synthesis, crystallographic structure, down shifting luminescence of Er(III) activated GdSr2AlO5 nanophosphors: An efficient green emitter for solid state lighting

In order to investigate a potential phosphor material for solid state illumination applications, we developed a series of green light emanating Er3+ doped GdSr2AlO5 (GSA) phosphors using the gel-combustion process. Diffraction investigation reveals that the fabricated nanophosphors are of tetragonal symmetry with I4/mcm (140) space group. SEM and TEM micrograph defines the almost smooth, irregular and agglomerated morphology with particle size in nano domain. Calculated band gap energy (5.769 eV) of the optimized sample depicts it's almost semiconductor behaviour. EDX spectral lines affirm the composition and pure synthesis of the prepared nanophosphors. The emission spectra of all doped samples consists of one most intense emission band at 550 nm with 4S3/2→4I15/2 transition and three very less intense bands at 406, 520 and 665 nm with 2H9/2→4I15/2, 2H11/2→4I15/2 and 4F9/2→4I15/2 separately. Due to concentration quenching phenomena, intensity of luminous bands gradually rises with the content of Er3+ doped ions up to 0.04 mol after that it starts to decrease regularly. Electric quadrupole-quadrupole interaction among the dopant ions was accountable for this quenching. Lifetime analysis confirms that the decay time is consistently declines with successive addition of trivalent erbium ions. This was due to the increment in the non-radiative path transitions. Suitable location of CIE point in the green region, high CCT and color purity values of the fabricated GdSr2AlO5:Er3+ phosphors endorse their probable utilization in field of solid state lighting.

Crystal Phase Refinement and Optical Features of Highly Efficient Green Light Radiating Ca9Y(VO4)7: Er3+ Nanophosphors for Emerging Solid-state Lighting Applications.

Ca9Y(VO4)7 phosphor activated with Er3+ ions have been developed by the urea-aided solution combustion technique. XRD profiles assisted with Rietveld refinement executed over-developed Er3+-activated Ca9Y(VO4)7 powder, revealed a trigonal phase with the R3c space group. The electron microscope techniques namely TEM and SEM characterize the size and surface-linked qualities of the developed nanopowder, respectively. The uniform distribution of various elements in the nanocrystalline sample is authenticated by an energy-dispersive spectroscopy (EDS) system. The Eg (band gap) value of 3.64eV for Ca9Y0.9Er0.1(VO4)7 and 3.74eV for Ca9Y(VO4)7 has been estimated. Upon 382nm excitation, Er3+: Ca9Y(VO4)7 phosphor gives rise to the bright green emission owing to the 4S3/2 → 4I15/2 transition. The concentration quenching after 10mol% composition of trivalent erbium ions is attributed to dipole-dipole interlinkages in accordance with Dexter's theory. The radiative lifetime (1.1083 ms), non-radiative rates (0.2079 ms- 1), quantum efficiency (79%), along with colorimetric parameters i.e. CIE x (= 0.2577), y (= 0.4566), and CCT quantities offer Ca9Y0.9Er0.1(VO4)7 as a proficient green radiating nanomaterial for RGB phosphors in solid-state applications.

Er3+-doped Y4Al2O9 nanophosphors for advance display applications: Synthesis, crystal chemistry and down conversion photoluminescent investigation

A gel-combustion approach was positively used to synthesize a series of cool greenish light emitter Y4-xAl2O9:xEr3+ (x = 1–5 mol %) nanophosphors and their structural, vibrational, morphological and luminescent characteristics have been examined for display applications. Studies of X-ray diffraction and structural refinement show that synthesized nanophosphors are made up of a single phase with a monoclinical crystal structure having P21/c space group. Transmission electron microscope (TEM) image manifests occurrence of non-uniform agglomeration of particles in the dominion of nano region. Emission spectra entail strongest band located at 549 nm due to 4S3/2 → 4I15/2 transition of trivalent erbium ion, producing greenish light. Concentration quenching (CQ) was attributed to exchange interactions (quadruple-quadruple), with an optimum concentration at 3 mol %. The lifetime of 549 nm emission decreases with higher Er3+ addition. The CIE chromaticity coordinates of Y4-xAl2O9:xEr3+ (x = 1–5 mol %) nanosamples were found in the greenish area. These obtained results of Y4-xAl2O9:xEr3+ (x = 1–5 mol %) nanophosphors are supportive for the usage of prepared nanophosphors as green component in display fabrication and other lighting foundations.

Enhanced Er3+ photoluminescence in sodium borate glasses containing silver nanoparticles for photonic functionalities

Herein, the titled glass routed with silver nanoparticles (achieved using thermal–reducing agent) containing trivalent erbium ions was synthesized via the melt–quench process. The electronic microscopic and linear absorption outcomes of glasses confirmed the formation of Ag0 nanoparticles. The prepared glass specimen was annealed at 400, 450 and 500 °C, it was identified that the photoluminescence properties were highest at 450 °C. Therefore, we considered this 450 °C as optimized temperature, since further annealing at this temperature for different durations causes significant improvement in photoluminescence properties compared to the properties obtained at other temperatures. The annealing at 450 °C for was performed for 0, 5, 10, 15 and 25 h to understand the influence of annealing duration on the optical absorption, visible and infrared photoluminescence properties of the prepared glass system. The photoluminescence intensity and related parameters such as bandwidth, gain bandwidth and quantum efficiency and also lifetime values of excited state for infrared emission transition were improved monotonously with annealing duration. The augmentation in the investigated properties was ascribed to the local field–produced by silver nanoparticles and the energy transfer from silver nanoparticles to erbium ions. The outcomes instantiate that the titled glass embedded with silver nanoparticles containing erbium ions annealed for 15 h at 450 °C could be useful for optoelectronic and photonic applications.

First-principles calculations of local structure and electronic properties of Er<sup>3+</sup>-doped TiO<sub>2</sub>

Trivalent rare earth erbium ion (Er<sup>3+</sup>) doped titanium oxide (TiO<sub>2</sub>) can possess a very wide range of applications due to its excellent optoelectronic properties, thus standing out among many rare-earth-doped luminescent crystals. However, the issues regarding local structure and electronic properties have not been finalized. To address these problems, the CALYPSO (Crystal structure AnaLYsis by Particle Swarm Optimization) method combined with the first-principles calculations is employed, and many converged structures of Er<sup>3+</sup>-doped TiO<sub>2</sub> are successfully obtained. Further structural optimization is performed by using the VASP (Vienna <i>ab initio</i> simulation package) software package, and we report for the first time that the lowest energy structure of Er<sup>3+</sup>-doped TiO<sub>2</sub> has the <inline-formula><tex-math id="M2">\begin{document}$ P\overline 4 $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20221847_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="24-20221847_M2.png"/></alternatives></inline-formula><i>m</i>2 symmetry. It can be observed that the doped Er<sup>3+</sup> ions enter into the host crystal and occupy the positions of Ti<sup>4+</sup> ions, resulting in structural distortion, which eventually leads the local Er<sup>3+</sup> coordination site symmetry to reduce from <i>D</i><sub>2<i>d</i></sub> into <i>C</i><sub>2<i>v</i></sub>. We speculate that there are two reasons: 1) the difference in charge between Er<sup>3+</sup> ions and Ti<sup>4+</sup> ions leads to charge compensation; 2) the difference between their electron radii is obvious: the radius is 0.0881 for Er<sup>3+</sup> ion and 0.0881 for Ti<sup>4+</sup> ion. In addition, during the structural search, we also find many metastable structures that may exist at a special temperature or pressure, which play an important role in the studying of structural evolution. When the electronic band structure of the Er<sup>3+</sup>-doped TiO<sub>2</sub> system is calculated, we adopt the method of local density approximation (LDA) combined with the on-site Coulomb repulsion parameter <i>U</i> to accurately describe the strongly correlated system. For the specific value of <i>U</i>, we adopt 3.5 eV and 7.6 eV to describe the strong correlation of 3d electrons of Ti<sup>4+</sup> ions and 4f electrons of Er<sup>3+</sup> ions, respectively. According to the calculation of electronic properties, the band gap value of Er<sup>3+</sup> doped TiO<sub>2</sub> is about 2.27 eV, which is lower than that of the host crystal (<i>E</i><sub>g</sub> = 2.40 eV). The results show that the reduction in the band gap is mainly caused by the f state of Er<sup>3+</sup> ions. The doping of Er ion does reduce the band gap value, but it does not change the conductivity of the system, which have great application prospect in diode-pumped laser. These findings not only provide the data for further exploring the properties and applications of Er<sup>3+</sup>:TiO<sub>2</sub> crystals, but also present an approach to studying other rare-earth-doped crystalline materials.

Judd-Ofelt analysis of spectroscopic measurements of Er3+ doped boro-zincate glasses

• Combined spectral and thermal measurements of high zinc borate glasses doped with different concentrations of Er3+ ions were carried out for investigation this system to be used in optical devises. Glasses based on the base composition (ZnO 70 – B 2 O 3 30 mol %) containing increasing Er 2 O 3 as dopant (0.2 → 2.2 mol%) were synthesized by traditional melting. Collective investigation was done through measuring their UV-visible and structural FTIR spectra. The density and derived physical properties were calculated in relation to the constitution and percent of rare-earth oxide. Optical absorption studies show specific and characteristic peaks which are correlated with the absorption of Er 3+ originated from the ground state 4 I 15/2 to several possible energy transitions. Structural IR data indicate distinct and extended bands from 400-1600 cm −1 which are assigned to the two known characteristic borate units with triangular and tetrahedral coordinations (BO 3 , BO 4 ). The possible forming of ZnO 4 is considered due to the abundance of ZnO (70 mol%) but the intensities of the vibrations of the two borate units are distinctively higher due to the known lightest boron element which is reflected on its oxide (B 2 O 3 ) than other glass forming oxides. The IR spectra have been confirmed by the measurements of the IR spectrum of pure crystalline ZnO to elucidate its specific vibrational sites. The density and molar volume data are correlated with the trivalent erbium ions concentration and their housing in the glass structure. The various optical parameters of the Er 2 O 3 -doped glasses were derived and analyzed in relation to the concentration of Er 3+ ions.

3D printed and spiral lithographically patterned erbium-doped polymer micro-waveguide amplifiers

Infrared (IR)-emitting RE doped materials have been extensively used to fabricate active components of integrated optical devices in various fields, such as fiber amplifiers, telecommunications, optoelectronics, and waveguides. Among various RE elements, trivalent erbium ions (Er 3+) are of great interest since their emissive behavior span the low loss telecommunication window of 1300–1650 nm. In this paper, we report two types of polymeric waveguide amplifiers. 8 cm long, lithographically patterned spiral waveguides provide 8 dB of gain using a 980 nm pump power of 95 mW. Gain is observed from 1530 to 1590 nm. We further report the first demonstration of polymeric waveguide amplifiers fabricated using 3D printing methods based on two-photon lithography, paving the way for rapid prototyping of active 3D printed devices and active photonic devices which may transcend planar limitations.

Metasurface‐Enhanced Photon Upconversion upon 1550 nm Excitation

AbstractPhoton upconversion upon 1550 nm excitation is of high relevance for applications in the third biological excitation window, for photovoltaics beyond current limitations, and enables appealing options in the field of glass fiber telecommunications. Trivalent doped erbium ions (Er3+) are the material of choice for 1550 nm excited upconversion, however, they suffer from a low absorption cross‐section and a low brightness. Therefore, the ability of silicon metasurfaces to provide greatly enhanced electrical near‐fields is employed to enable efficient photon upconversion even at low external illumination conditions. Hexagonally shaped β‐NaYF4:Er3+ nanoparticles are placed on large‐area silicon metasurfaces designed to convert near‐infrared (1550 nm) to visible light. More than 2400‐fold enhanced photon upconversion luminescence is achieved by using this metasurface instead of a planar substrate. With the aid of optical simulations based on the finite‐element method, this result is attributed to the coupling of the excitation source with metasurface resonances at appropriate incident angles. Analysis of the excitation power density dependence of upconversion luminescence and red‐to‐green‐emission ratios enables the estimation of nanoscale near‐field enhancement on the metasurface. The findings permit the significant reduction of required external excitation intensities for photon upconversion of 1550 nm light, opening perspectives in biophotonics, telecommunication, and photovoltaics.

Influence of PbF2 content on optical thermometry of Er3+/Yb3+ co-doped tungsten sodium phosphate glasses

Abstract The green emissions of the trivalent erbium ions exhibit promising applications in photonics, such as the development of solid-state lasers, optical sensors, and light-emitting diodes (LED). In this work, the intensity of the emissions of two thermally coupled levels 2H11/2 and 4S3/2 excited states of Er3+ ions are studied in Er3+/Yb3+ co-doped tungsten sodium phosphate oxyfluoride glasses. The results demonstrate that an increase in the content of the PbF2 leads to an enhancement in the performance of these samples as optical sensors, and amplifies the relative thermal sensitivity from 0.82% K−1 to 1.15% K−1 for glass samples containing 10 mol% and 50 mol% of PbF2, respectively. Additionally, the effect of PbF2 is discussed in terms of the modifications of the site symmetries around Er3+ ions and changes in the energy gap between the thermally coupled levels, which implied in the improvement of the absolute thermal sensitivity at higher temperatures for high PbF2 contained sample.

Erbium doped Bi2O3-B2O3 glass-ceramics containing Bi3B5O12 and CaF2 nanocrystallites for 1.53 μm fiber lasers

Trivalent erbium ions doped Bi2O3-B2O3 transparent glass ceramics containing CaF2 were prepared and characterized through X -ray diffraction, scanning electron microscopy, Fourier transform infrared absorption, optical absorption, and near infrared emission for 1.53 μm fiber lasers. The glass ceramics obtained by applying thermal treatment at 575 °C for 5 h and 575 °C for 10 h contain Bi3B5O12 and CaF2 crystallites. The Judd-Ofelt theory was applied to evaluate various spectroscopic and laser characteristic properties. The NIR emission corresponding to the 4I13/2 → 4I15/2 (∼1.53 μm) transition was studied by exciting the samples at 514.5 nm laser radiation. The stimulated emission cross-sections of ∼1.53 μm luminescence were also obtained applying the Mc Cumber theory. The experimental results confirm that the transparent glass ceramic obtained at a thermal treatment of 575 °C for 10 h is more suitable to design fiber lasers for diverse applications in the fields of industry, medicine and scientific research.

Preparation and application of iron oxide/persimmon tannin/ graphene oxide nanocomposites for efficient adsorption of erbium from aqueous solution

Rare earth elements (REEs) are used for the development of new energy materials owing to their intrinsic physicochemical property. However, excess REEs in water threaten the safety of animals, plants and humans. An efficient way to separate REEs from the water is therefore needed. In this study, a biosorbent consisting of iron oxide (Fe3O4), persimmon tannin (PT), and graphene oxide (GO) as Fe3O4/PT/GO was prepared, and the adsorption of trivalent erbium (Er3+) ions from aqueous solution was investigated. The adsorption process for Er3+ ions conforms to pseudo-second order kinetic and the Langmuir isotherm model behavior. Thermodynamic studies indicate that the adsorption process is spontaneous and endothermic. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) analysis, and vibrating sample magnetometer (VSM) were used to assess the adsorption mechanism of Er3+ ions onto the Fe3O4/PT/GO biosorbent. A combination of electrostatic interactions, redox reactivity and chelation are responsible for adsorption of Er3+ ions on the Fe3O4/PT/GO biosorbent. The magnetic Fe3O4/PT/GO biosorbent can be easily separated under the magnetic field for effective recycle of Er3+ ions from aqueous solution. Therefore, this new biomass composite holds great promise for wastewater treatment.

Strongly enhanced upconversion in trivalent erbium ions by tailored gold nanostructures: Toward high-efficient silicon-based photovoltaics

Upconversion of sub-band-gap photons constitutes a promising way for improving the efficiency of silicon-based solar cells beyond the Shockley-Queisser limit. 1500nm to 980nm upconversion by trivalent erbium ions is well-suited for this purpose, but the small absorption cross section hinders real-world applications. We employ tailored gold nanostructures to vastly improve the upconversion efficiency in erbium-doped TiO2 thin films. The nanostructures are found using topology optimization and parameter optimization and fabricated by electron beam lithography. In qualitative agreement with a theoretical model, the samples show substantial electric-field enhancements inside the upconverting films for excitation at 1500nm for both s- and p-polarization under a wide range of incidence angles and excitation intensities. An unprecedented upconversion enhancement of 913±51 is observed at 1.7Wcm−2. We derive a semi-empirical expression for the photonically enhanced upconversion efficiency, valid for all excitation intensities. This allows us to determine the upconversion properties needed to achieve significant improvements in real-world solar-cell devices through photonic-enhanced upconversion.

Influence of Er3+ ions on structural and fluorescence properties of SiO2-B2O3- Na2Co3-NaF-CaF2 glasses for broadband 1.53 μm optical amplifier applications

The oxyfluoroborosilicate (SiO2-B2O3- Na2Co3-NaF-CaF2) glasses activated with varied concentrations of trivalent Erbium ions have been prepared by using conventional melt quenching method. The structural, optical and luminescence properties were examined with X-ray diffraction, X-ray Photoelectron, Fourier Transform Infrared, Optical absorption, fluorescence emission spectra and lifetime decay analysis. From the absorption spectra of the prepared glasses, oscillatory strength of each band was calculated and evaluated the bonding parameters (β, δ) values. Judd-Ofelt theory had been used to determine the spectral intensity parameters (Ωλ = 2,4 and 6) and some important radiative parameters like total radiative transition probability (AT), radiative lifetime (τR) and radiative branching ratios were also calculated for 4I15/2 → 4I13/2 transition. Optical band gap energy (Eopt) estimated/determined for direct and indirect allowed transitions. From the NIR emission spectra, 0.5 mol% Erbium ions activated glass possesses maximum intensity for 4I13/2 → 4I15/2 transition and evaluated the stimulated emission cross-section (σemi) (9.47 × 10−21 cm2), Gain bandwidth parameter (σemi x ∆λeff) (0.823 × 10−25 cm3) and gain per unit length (σemi x τmes) (51.65 × 10−25 cm2s) for this prepared glass and compared with other reported glasses. Using Mc Cumber theory, σemi was calculated for 4I13/2 → 4I15/2 transition from the absorption spectrum of 0.5 mol% Er3+ ions doped glass. The lifetime (τm) of 4I13/2 level was decreased from 6.94, 6.61, 5346, 5.44 and 2.74 ms with the increase in Erbium ions concentrations from 0.05, 0.1, 0.5, 1.0 and 2.0 mol% respectively. This decrease may be due to concentration quenching effect. The high values of (σemi) (9.47 x 10−21 cm2), (σemi x ∆λeff) (0.823 × 10−25 cm3) and τm (5.45 ms) for 0.5 mol% of Er3+ ions activated oxyfluoroborosilicate glass suggesting that the glasses could be used as potential candidate for 1.53 μm optical amplifier applications.

Enhanced single-band red upconversion luminescence of α-NaErF4:Mn nanoparticles by a novel hollow-shell structure under multiple wavelength excitation

Upconversion nanoparticles (UCNPs) doped with lanthanide ions have potential applications in biomedical, solar cells and displays. However, the intensity of the upconversion luminescence (UCL) is limited by the surface effects of nanomaterials, lattice defects, etc. Here, a novel α-NaErF4 hollow nanocube is fabricated by using divalent manganese ions (Mn2+) to substitute trivalent erbium ions (Er3+) in the NaErF4 matrix. The hollow-shell structure can weaken the luminescence quenching and surface quenching effects, reduce the energy loss of higher energy levels in nanoparticles, and improve the light capture ability of nanoparticles. So the UCL of α-NaErF4 hollow nanocubes is greatly improved, which is 14, 790 and 1071 times higher than that of the β-NaErF4 under 808, 980 and 1530 nm laser excitation, respectively, and the emission in the red region is enhanced respectively by 69, 2049 and 2902 times. In particular, the hollow nanocubes emit intense single-band red emission under the three different wavelengths, respectively. Moreover, the magnetization of α-NaErF4 hollow nanocubes is 2.16 emu g−1 at room temperature, which is larger than that of gadolinium-based materials. Hollow-shell structure, excellent paramagnetism and single-band red upconversion emission excited by various wavelengths will create NaErF4:40Mn UCNPs a good application prospect in the biomedical field.

Understanding the downconversion photoluminescence of NaLaP4O12:Er3+ phosphor

Abstract We have employed the solid-state chemical reaction to construct series of trivalent erbium ions activated NaLaP 4 O 12 (abbreviated as: NLP) phosphors. The structural investigation indicates that NLP:Er 3+ crystalline products are purely monoclinic phase with micron particles. Trivalent erbium ions with the substitution for lanthanum are successfully inserted into NLP host lattice. The UV–Vis diffuse reflectance absorption performance, doping Er 3+ content-dependent downconversion photoluminescence, content quenching mechanism were reported in this paper. Upon near UV (378 nm) excitation, yellow/yellow-green visible light with the dominant 4 S 3/2 → 4 I 15/2 emission of trivalent erbium is displayed. Yellow-green emitting NLP:2%Er 3+ sample has the maximum intensity and main luminescent peaks at 541 and 549 nm. The content quenching is related to the dipolar interaction. Additionally, the detailed investigation on CIE chromaticity coordinates, CP and CCT reveals that the title product has promising application in the field of white LEDs excited by near UV light.

Interface-Dependent Radiative Lifetimes of Yb3+, Er3+ Co-doped Single NaYF4 Upconversion Nanowires.

The development of upconversion nanomaterials for many photonic applications requires a detailed understanding of their radiative lifetimes that in turn depend critically on local environmental conditions. In this work, hexagonal (β-phase) sodium-yttrium-fluoride (NaYF4) nanowires (NWs) were synthesized and substitutionally co-doped with a luminescent solid solution of trivalent erbium and ytterbium ions. A single-beam laser trapping instrument was used in tandem with a piezo-controlled, variable-temperature stage to precisely vary the nanowire's distance from the substrate. The spontaneous photoluminescence lifetime of the 4S3/2 → 4I15/2 transition from Er3+ ions was observed to change by >60% depending on the ions' separation distance from a planar (water/glass) dielectric interface. The 4S3/2 state lifetime is observed to increase by a factor of 1.62 ± 0.01 as the distance from the quartz coverslip increases from ∼0 nm to ∼40 μm. Less significant changes in the luminescence lifetime (≤10%) were observed over a temperature range between 25 and 50 °C. The distance dependence of the lifetime is interpreted quantitatively in the context of classical electromagnetic coupling between Er3+ ions within the nanowire and the adjacent dielectric interface. We also demonstrate potential applications of the NaYF4 NWs for both controlling and probing temperatures at nanometer scales by integrating them within a poly(dimethylsiloxane) composite matrix.

Synthesis and green luminescence of low cost Er2O3 doped zinc silicate glass-ceramics as laser materials

The compositions of 3 wt.% trivalent erbium ions (Er3+) doped zinc silicate (Zn2SiO4) glass-ceramics was fabricated from waste materials via conventional solid-state method. From the XRD and FESEM results designate that the diffraction peaks of 3 wt.%Er3+:Zn2SiO4 glass-ceramics improved with the heat treatment progression and homogeneously distributed in hexagonal and rectangular shapes. From UV–vis measurement, three detected peaks of optical absorption that corresponding to the optical transitions of Er3+ ions are located at 492 nm (4F7/2), 524 nm (2H11/2), and 650 nm (4F9/2). The intensive sharp characteristic emission that correlated with Er3+ luminescence is resolved in photoluminescence spectra at room temperature and gives a yellow-green light colour emission at 559 nm under 385 nm excitation peaks.