Incorporation Of Er Research Articles

Metallic surface doping of SiO<SUB align="right">x nanowires

Utilising active oxidation processes at higher temperatures and low O 2 partial pressures, a dense layer of sub-stoichiometric silica nanowires can be readily fabricated directly from an underlying metal coated Si substrate. These unique surfaces are thermally and chemically robust, providing an ideal supporting substrate for secondary materials for a range of applications, including photocatalysis and sensing. In this report we discuss methods to incorporate volume and surface metallic dopants via ion implantation into and onto these unique nanostructures. At higher temperatures, these dopants form metallic nanoparticles on the nanowire surface and when re-subjected to an active oxidation environment result in the onset of secondary nanowire growth. The incorporation of metallic Er 3+ ions is used to optically probe the doping properties, including incorporation and agglomeration. Evidence for metal dopant incorporation during the nanowire growth is presented suggesting that hierarchically doped nanostructured silica surfaces can be readily grown via simple thermal processing.

Ionically conducting Er3+-doped DNA-based biomembranes for electrochromic devices

Biopolymer-based membranes have particular interest due to their biocompatibility, Biodegradability, easy extraction from natural resources and low cost. The incorporation of Er3+ ions into natural macromolecule hosts with the purpose of producing highly efficient emitting phosphors is of widespread interest in materials science, due to their important roles in display devices. Thus, biomembranes may be viewed as innovative materials for the area of optics. This paper describes studies of luminescent material DNA-based membranes doped with erbium triflate and demonstrates that their potential technological applications may be expanded to electrochromic devices. The sample that exhibits the highest ionic conductivity is DNA10Er, (1.17×10−5 and 7.76×10−4 S.cm−1 at 30 and 100°C, respectively). DSC, XRD and POM showed that the inclusion of the guest salt into DNA does not change significantly its amorphous nature. The overall redox stability was ca. 2.0V indicating that these materials have an acceptable stability window for applications in solid state electrochemical devices. The EPR analysis suggested that the Er3+ ions are distributed in various environments. A small ECD comprising a Er3+-doped DNA-based membrane was assembled and tested by cyclic voltammetry and chronoamperometry. These electrochemical analyses revealed a pale blue color to transparent color change and a decrease of the charge density from -4.0 to -1.2 mC.cm−2 during 4000 color/bleaching cycles.

Effect of retrapping on the persistent luminescence in strontium silicate orange–yellow phosphor

The orange–yellow long persistent luminescence in Sr{sub 3}SiO{sub 5}:Eu{sup 2+}, Er{sup 3+} with the chromaticity coordination of (0.48, 0.49) can persist for over 20 h above the recognizable intensity level (≥0.32 mcd/m{sup 2}) because of retrapping carriers by the deep traps. The incorporation of Er{sup 3+} into Sr{sub 3}SiO{sub 5}:Eu{sup 2+} generates a large number of shallow traps responsible for the fast decay component as well as deep traps responsible for the decay tail of the LPL. It demonstrates that the retrapping of the carrier released from a trap plays an important role in the persistent luminescence process. - Graphical abstract: LPL decay curves of Sr{sub 3−x−y}SiO{sub 5}:xEu{sup 2+}, yEr{sup 3+} (x=0.0025, y=0, 0.0025). Inset: Orange–yellow emission images recorded using a classic Reflex digital camera with exposure times varying with the persistent luminescence times. Display Omitted - Highlights: • The persistence time of Sr{sub 3}SiO{sub 5}:Eu{sup 2+}, Er{sup 3+} lasts over 20 h above the recognizable intensity level. • The incorporation of Er{sup 3+} into Sr{sub 3}SiO{sub 5}:Eu{sup 2+} generates a large number of shallow traps. • The experimental results provide an evidence for the retrapping process in LPL processes.

Electrically active Er doping in InAs, In0.53Ga0.47As, and GaAs

The electron concentration in dilute alloys of Er in GaAs, In0.53Ga0.47As, and InAs grown by molecular beam epitaxy is studied as a function of Er concentration and In content. Using first-principles calculations based on hybrid density functional theory, we attribute an observed increase in conduction electron concentration to Er incorporation on interstitial sites. Er also incorporates on substitutional sites where it is isovalent and electrically inactive. The formation energy of interstitial Er in InAs is significantly smaller than in GaAs, allowing for more electrically active Er in InAs. The results provide insight into characteristics of rare-earth elements as dopants in semiconductors.

Effect of Er‐doping on the structural and optical properties of Cd2V2O7

AbstractThe melt‐quenching method was used to prepare two groups of samples using CdO and V2O5 as starting materials. Taking into account that a crystalline‐amorphous phase transition would be expected for the CdO–V2O5 system, a first batch was prepared varying the proportions of CdO and V2O5 in the intervals 60–95 and 40–5 wt%, respectively. With the aim of investigating the effect of erbium in the phase transition and crystalline quality of the first group of samples, a second batch was fabricated with the same proportions of CdO and V2O5, with the addition of 5 wt% of Er(NO3)5H2O as source of Er3+ ions. It was found that crystalline or amorphous samples could be obtained depending on the relative concentrations of CdO and V2O5, and that the borderline between amorphous and crystalline samples was affected by the incorporation of Er. From X‐ray diffraction, it was possible to identify the formation of the ternary compound Cd2V2O7 in the crystalline cases. The Raman and infrared bands in these samples were in agreement with the lattice modes of Cd2V2O7. Additionally, an improvement in the crystalline quality of Cd2V2O7 was obtained for the Er‐doped samples. The effect of the local environment around the Er3+ ions on the room temperature photoluminescence was also investigated for the amorphous and crystalline samples.

Electron Energy Loss Spectroscopy Analysis on the Preferential Incorporation of Er3+ Ions into Fluoride Nanocrystals in Oxyfluoride Glass‐Ceramics

The preferential incorporation of Er 3+ ions into the PbF 2 nanocrystals during the ceraming process of oxyfluoride glass was analyzed using electron energy loss spectroscopy analysis. Concentrations of Er 3+ ions were considerably higher in PbF 2 nanocrystals compared to those in the glass matrix. Changes in lineshapes of absorption spectra from Er 3+: 4 I 15/2→4 I 13/2 transition and lifetimes of the excited‐state Er 3+ (4 S 3/2 level) ions also supported the incorporation of Er 3+ ions into PbF 2 nanocrystals.

Synthesis and Characterization of Small Dimensional Structures of Er-Doped SnO2 and Erbium–Tin–Oxide

Microtubes of Er-doped SnO2, as well as nanorods and nanoparticles, have been fabricated by a thermal evaporation deposition method at temperatures between 1400 and 1500 degrees C, by using a pellet of compacted SnO2 and Er2O3 powder mixture as precursor. Er2Sn2O7 has been also detected by X-ray diffraction spectroscopy. Energy dispersive X-ray spectroscopy and photoelectron spectroscopy measurements demonstrate that the microtubes contain a small amount of Er, below 0.5 at. %, different from regions from the surface of the pellets where the tubes grow, which shows a variable Er concentration up to 25 at. %. Cathodoluminescence spectra confirmed the presence of Er in the microtubes, as well as in the surface of the pellet, where emissions in the visible and the infrared range at 1.87, 2.23, and 0.81 eV are observed. The luminescence signal varies as a function of the thermal parameters used during the microtubes growth. The mechanisms of Er incorporation are discussed.

Enhanced photocatalytic activity and upconversion luminescence of flowerlike hierarchical Bi2MoO6 microspheres by Er3+ doping

Abstract

Luminescence Properties of Er<sup>3+</sup>/Tm<sup>3+</sup>-Doped Ga<sub>2</sub>O<sub>3</sub>-Bi<sub>2</sub>O<sub>3</sub>-PbO-GeO<sub>2</sub> System Glasses

The visible and near infrared emission spectra of Er3+/Tm3+-doped Ga2O3-Bi2O3-PbO-GeO2(GBPG) glasses excited at 808 nm are experimentally investigated. The results reveal that 1.53 µm emission were enhanced with an increase of Er3+concentration. Furthermore, the incorporation of Er3+into Tm3+-doped systems has also resulted in intense 522, 545 and 693nm upconversion emission intensity and an weak 660 nm red emission. The possible mechanism and related discussions on this phenomenon have been presented. The results show that Er3+/Tm3+-codoped GBPG glass may be a promising materials for developing laser and fiber optical devices.

Synthesis and characterization of Er 3+ doped CaF 2 nanoparticles

Er 3+ doped CaF 2 nanoparticles were synthesized by a chemical co-precipitation method. Effect of the dopant concentrations on the structure and optical properties of the CaF 2 nanoparticles was investigated. The X-ray powder diffraction and transmission electron microscopy analysis was used to characterize the structure and morphology of the nanoparticles. The nanoparticles with different dopant concentration exhibited a sphere-like morphology with diameters of about 8–36 nm. The incorporation of Er 3+ ions into CaF 2 resulted in the decrease in grain size and deterioration of crystallinity, but enlarged the lattice constants of CaF 2. Additional annealing treatment at 400 °C to the prepared CaF 2 removed the NO 3 − and OH − groups adsorbed on the particles’ surfaces, and improved the optical properties of the nanoparticles. The fluorescence intensity, with a maximum at approximately 0.4 mol%, decreased with the increase in doping concentration because of concentration quenching.

Multiple excitation of silicon nanoclusters during erbium sensitization process in silicon rich oxide host

Sensitization of erbium through silicon nanocluster (Si-nc) in silicon rich oxide host has been analyzed through a statistical approach. Our analysis shows that significant fraction of Si-ncs can experience multiple excitations during the Er lifecycle. The probability of Si-nc being excited at every alternate cycles of excitation increases from small fractions to percentage levels for incident flux levels above 1018/cm2 s. We show that, for typical values of Er and Si-nc incorporation, saturating effects in Er luminescence starts at flux levels much lower than that for Si-nc excitation. Occurrence of multiple excitation of Si-nc has been correlated with the deteriorating effects in Er sensitization at higher flux incidence.

Growth and characterization of Er‐doped ZnO elongated nanostructures

AbstractEr‐doped ZnO nano‐ and microstructures have been grown by thermal treating of compacted mixtures of ZnO and Er2O3 powders and their optical properties have been studied by cathodoluminescence (CL). Annealing the pressed samples leads to the growth of nanoneedles and nanoneedle networks, as well as rods. CL measurements enable detection of the dopant incorporation into these structures as well as the influence of this incorporation on the defect structure. CL contrast reveals an inhomogeneous distribution of luminescent centers, showing differences in the Er incorporation degree as a function of morphology and structures of the rods. Spectral distribution of the luminescence also points toward a nonhomogeneous distribution of the dopant. The growth of hierarchical structures has also been studied.

Simultaneous Tailoring of Phase Evolution and Dopant Distribution in the Glassy Phase for Controllable Luminescence

Construction of an active composite with multicolor visible and broadband near-infrared luminescence is of great technological importance for various applications, including three-dimensional (3D) display, broadband telecommunication, and tunable lasers. The major challenge is the effective management of energy transfer between different dopants in composite. Here we present an in situ strategy for controlling energy transfer between multiple active centers via simultaneous tailoring of the evolution of phases and the distribution of dopants in the glassy phase. We show that the orderly precipitation of Ga(2)O(3) and LaF(3) nanocrystals and the selective incorporation of Ni(2+) and Er(3+) into them can be achieved. The obtained composite shows unique multicolor visible and broadband near-infrared emission. Possible mechanisms for the selective doping phenomenon are proposed, based on thorough structural and optical characterizations and crystal-field calculation results. Moreover, the strategy can be successfully extended to accomplish space-selective control of multicolor luminescence by employing the modulated stimulation field. The results suggest that the strategy could be applied to fabricate a multifunctional light source with a broad range of important host/activator combinations and to construct various types of three-dimensional active microstructures.

Upconversion luminescence from Er-N codoped of ZnO nanowires prepared by ion implantation method

Nitrogen and erbium co-doped of ZnO nanowires (NWs) are fabricated by ion implantation and subsequent annealing in air. The incorporation of Er3+ and N+ ions is verified by energy dispersive X-ray spectroscopy (EDS) and Raman spectra. The samples exhibit upconversion photoluminescence around ∼550nm and ∼660nm under an excitation at 980nm. It is discovered that the N-doped can drastically increase the upconversion photoluminescence intensity by modifying the local structure around Er3+ in ZnO matrix. The enhancement of the PL intensity by the N-doped is caused by the formation of ErO6−xNx octahedron complexes. With the increase of the annealing temperature (Ta), the Er3+ ions diffuse towards the surface of the NWs, which benefits the red emission and evokes the variation of intensity ratio owing to the existence of some organic groups.

Highly Efficient Near-IR Photoluminescence of Er3+ Immobilized in Mesoporous SBA-15

SiO2 mesoporous molecular sieve SBA-15 with the incorporation of erbium ions is studied as a novel type of nanoscopic composite photoluminescent material in this paper. To enhance the photoluminescence efficiency, two schemes have been used for the incorporation of Er3+ where (1) Er3+ is ligated with bis-(perfluoromethylsulfonyl)-aminate (PMS) forming Er(PMS)x-SBA-15 and (2) Yb3+ is codoped with Er3+ forming Yb-Er-SBA-15. As high as 11.17 × 10−21cm2 of fluorescent cross section at 1534 nm and 88 nm of “effective bandwidth” have been gained. It is a 29.3% boost in fluorescent cross section compared to what has been obtained in conventional silica. The upconversion coefficient in Yb-Er-SBA-15 is relatively small compared to that in other ordinary glass hosts. The increased fluorescent cross section and lowered upconversion coefficient could benefit for the high-gain optical amplifier. Finally, the Judd–Ofelt theory has also been used for the analyses of the optical spectra of Er(PMS)x-SBA-15.

Rare earth-doped lead borate glasses and transparent glass–ceramics: Structure–property relationship

Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass–ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu 3+ and Er 3+ ions. The observed BO 3 ↔ BO 4 conversion strongly depends on the relative PbO/B 2O 3 ratios in glass composition, giving important contribution to the luminescence intensities associated to 5D 0– 7F 2 and 5D 0– 7F 1 transitions of Eu 3+. The near-infrared luminescence and up-conversion spectra for Er 3+ ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er 3+ ions into the orthorhombic PbF 2 crystalline phase, which was identified using X-ray diffraction analysis.

Origin of periodic domain structure in Er 3+-doped β′-(Sm,Gd) 2(MoO 4) 3 crystal lines patterned by laser irradiations in glasses

Er 3+-doped β′-(Sm,Gd) 2(MoO 4) 3 crystal lines are patterned on the surface of Er 2O 3–Gd 2O 3–Sm 2O 3–MoO 3–B 2O 3 glasses by continuous-wave Yb:YVO 4 laser irradiations (wavelength: 1080 nm, power: 1.3 W, scanning speeds: 5 μm/s), and the origin of the periodicity of self-organized domain structures with high and low refractive index regions in crystal lines is examined from polarized optical microscope (POM) observations, micro-Raman scattering spectrum, and photoluminescence spectrum measurements. It is found that the periodicity of domain structures changes largely depending on Er 2O 3 content, i.e., the length of high (bright color in POM observations) and low (dark color) refractive index regions increases with increasing Er 2O 3 content and homogeneous crystal lines with no periodic domain structures are patterned in Er 2O 3–Sm 2O 3–MoO 3–B 2O 3 glass with no Gd 2O 3. Considering that the degree of ferroelasticities in β′-(Sm,Gd) 2(MoO 4) 3 crystals decreases due to the incorporation of Er 3+ ions, it is demonstrated that the origin of periodic domain structures in laser-patterned lines is due to spontaneous strains in ferroelastic β′-(Sm,Gd) 2(MoO 4) 3 crystals.

Energy transfer and up-conversion luminescence in Er 3+/Yb 3+ co-doped transparent glass ceramic containing YF 3 nano-crystals

Transparent glass ceramics containing YF 3 nano-crystals were fabricated by heat treatment of the SiO 2–Al 2O 3–NaF–YF 3–LnF 3 (Ln = Er, Yb) glasses. X-ray diffraction and transmission electron microscopy analyses evidenced the homogeneous distribution of spherical YF 3 nano-crystals sized 25–30 nm among the glassy matrix. Energy dispersive X-ray spectroscopy measurement, combined with the Stark splitting of the absorption and emission bands, verified the incorporation of Er 3+ and Yb 3+ ions into YF 3 nano-crystals. The infrared to visible up-conversion emission of Er 3+ intensified with the increasing of Yb 3+ concentration, ascribing to the increase of the efficiency of non-radiative energy transfer from Yb 3+ to Er 3+ which exceeded 45% for the 0.5Er 3+/1.0Yb 3+ co-doped sample. The up-conversion luminescence at 545 and 660 nm were affirmed coming from two-photon excitation process.

Writing of rare-earth ion doped lithium niobate line patterns in glass by laser scanning

A glass of Er3+ doped Li2O-Nb2O5-SiO2-B2O3 with an addition of CuO or Sm2O3 crystallizing nonlinear optical lithium niobate LiNbO3 (LN) is developed. Crystalline lines of LN have been fabricated on the glass surface by continuous wave Yb fiber laser irradiations with a wavelength of 1080 nm. The laser written LN crystalline lines have been found, by means of electron back scattering method, micro-Raman and second harmonic experiments, to be well oriented along the laser scanning direction. For the testing of optical waveguides crystal lines exhibit light confinements due to the refractive index (n) changes between the patterned line (n∼2.2) and the glass matrix (n=1.7). The analysis of the confocal micro-luminescence spectra obtained for the crystalline line indicates the incorporation of Er3+ ions into LN crystals.

Influence of erbium on the electronic structure of Fe(65−x)Mo14C15B6Erx (x=,1,2) bulk metallic glasses

Fe ( 65 − x ) Mo 14 C 15 B 6 Er x bulk metallic glasses have been investigated by means of photoelectron spectroscopy. In order to obtain a clean surface the samples were fractured and analyzed in vacuum. The impact of the incorporation of Er on the local atomic structure, the bonding, and the valence band density of states was examined. Our results show that Er addition modifies the B–C bonding environment, which is expressed in the appearance of an additional peak in the C 1s core level. It also affects the Fe 3s multiplet splitting, indicating changes in the valence band electronic configuration. The change in the electronic structure is corroborated by examination of x-ray photoelectron spectroscopy (XPS) valence band spectra.