Yellow Band Research Articles

Er3+/Dy3+ codoped B2O3-TeO2-PbO-ZnO-Li2O-Na2O glasses: Optical absorption and fluorescence features study for visible and near-infrared fiber laser applications

Using melt quenching method, singly Er3+, Dy3+-doped and Er3+/Dy3+-codoped multicomponent borotellurite glasses in the composition (50-x-y) B2O3-10 TeO2-10 PbO-10 ZnO-10 Li2O-10 Na2O-(x) Er2O3- (y) 0.5 Dy2O3 ((x=0.5, 1.0; y=0); (x=0; y=0.5, 1.0); and (x=0.5; y=0.5, 1.0; x=1.0; y=0.5, 1.0)) (mol%) were synthesized. For the fabricated samples, optical absorption, photoluminescence excitation (PLE), photoluminescence (PL), near-infrared (NIR) fluorescence and decay lifetime measurements have been performed. For singly Er3+ and Dy3+-doped samples, Judd-Ofelt (J-O) parameters, Ωt, were calculated following the absorption spectra and the derived Ωt parameters are utilized to predict respective radiative features for these glasses. The PL spectra of the Er3+ and Dy3+ singly doped glasses, excited at 378 nm (Er3+: 4I15/2 → 4G11/2) and 350 nm (Dy3+: 6H15/2→4M15/2,6P7/2), show important green and yellow emission bands at wavelengths 554 nm (Er3+: 4S3/2→4I15/2) and at 574 nm (Dy3+: 4F9/2→6H13/2), respectively. The PL decay curves for Er3+: 4S3/2 level and Dy3+: 4F9/2 level follow single exponential, and non-exponential nature, respectively, for the singly Er3+ and Dy3+-doped samples. For singly 1.0 mol% Er3+ and 0.5 mol% Dy3+-doped samples, the evaluated stimulated emission cross-sections (σPE) for the transitions at λem. = 0550 nm, and 574 nm are equal to 20.923×10-20 cm2 and 0. 526×10-20 cm2, while the gain bandwidths are 3.975×10-25 cm3 and 0.789×10-26 cm3, respectively. For all the Er3+-containing glasses, a broad NIR emission band centered at 1.532 μm (4I13/2→4I15/2) is noticed under both 808 and 980 nm laser diode (LD) excitations, whereas the singly 1.0 mol% Er3+-doped sample shows the highest NIR emission intensity with a full-width at half maximum (FWHM) equal to ~69 and 62 nm, respectively, at these pumping wavelengths. Moreover, the calculated highest (σPE) of 1532 nm NIR emission when pumped by 980 nm is 2.669×10-20 cm2 and gain per unit length is 1.06×10-23 cm2s, for singly 1.0 mol% Er3+-doped glass. Additionally, for Er3+/Dy3+-codoped samples, with the decrement of Er3+: NIR emissions, energy transfer (ET) from Er3+→Dy3+ ions is identified upon both 808 and 980 nm LD pumping. For all Er3+/Dy3+-codoped glasses, the Er3+: 4I13/2 level decay time decreased with increasing Dy2O3 content and the NIR fluorescence decay curves exhibit single exponential nature. Under 980 nm excitation, the computed energy transfer efficiency (ηET) from Er3+: 4I13/2 to Dy3+: 6H11/2 level is 22.9% for the 1.0 Er3+/0.5 Dy3+ (mol%)-codoped glass. Under 808 and 980 nm pumping, the mechanism of the ET processes between Er3+ and Dy3+ ions was discussed in detail. Further, for 1.0 mol% Er3+ singly doped sample, a theoretical gain coefficient value of 17.01 dB/cm is obtained with an excited Er3+ ion fractional factor of 0.6. Following the explored visible and NIR optical results, the synthesized glasses might be useful for visible and NIR fiber lasers application.

RETRACTED: Structural, morphological and optical analysis related to the origin of the green and red emission band in a chiral Schiff base

The structural, morphological and optical properties of an enantiopure Schiff base, namely [(S)-(+)-[(1-naphthyl)-N-(1-benzo[b]tiophen-2-yl)methylidene]ethylamine] (Bt-Naph) are reported. By using Scanning Electron Microscopy (SEM), tubular crystals of different sizes can be seen. X-ray diffraction studies showed an orthorhombic phase, which has been confirmed by powder X-ray diffraction (XRD) analysis applying Bragg's law. The absorbance results showed typical bands of organic molecules located in the UV region for π→π* and n→π* electronic transitions. Considering the behavior of this organic crystal as similar to other crystalline materials, the Tauc law was applied to investigate the band gap energy (Eg). Two electronic transitions were experimentally evaluated: Eg ∼3.5 eV and Eg ∼4.7 eV. The photoluminescence spectroscopy showed a broad emission band located in the visible region at ∼575 nm, identified as a green emission (GE) band. Deconvolution of the spectra displayed two emission bands located at ∼558 nm and ∼672 nm, and the latter was assigned to a yellow emission band. Finally, the Raman spectroscopy exhibited peaks associated with different vibrational modes, typical of molecules containing aromatic rings.

Investigating efficient energy transfer in novel strategy-obtained Gd2O2S:Dy3+, Eu3+ nanofibers endowed with white emitting and magnetic dual-functionality

Gd2O2S:Dy3+, Eu3+ nanofibers were successfully prepared via electrospinning combined with dual-boat sulfurization approach. X-ray diffractometer analysis reveals that Gd2O2S:Dy3+, Eu3+ nanofibers possess hexagonal structure (space group: P3¯m1). The as-synthesized samples are apparently nanofibers in morphology with field emission scanning electron microscope investigation, and the average diameters of PVP/(Gd(NO3)3+Dy(NO3)3+Eu(NO3)3) electrospinning-produced nanofibers and Gd2O2S:Dy3+, Eu3+ nanofibers are 454.10 ± 4.97 nm and 162.93 ± 0.75 nm, respectively. Gd2O2S:Dy3+ nanofibers demonstrate the typical blue, yellow and weak red emission bands via the excitation of 268-nm ultraviolet. Resulted from the effective spectral overlap between Dy3+ and Eu3+, Dy3+ is proved to be the effective sensitizer for Eu3+, which leads to the energy transfer of Dy3+→Eu3+ in Gd2O2S host and improved red emission of Eu3+. Further, the mechanism of energy transfer between Dy3+ and Eu3+ is determined to be an electric doublet-electric doublet interaction. Additionally, variable fluorescent color, including blue, red and especially white, can be achieved by properly modulating the ratios between Dy3+ and Eu3+. The formation mechanism of Gd2O2S:Dy3+, Eu3+ nanofibers is also advanced. Besides, the Gd2O2S:Dy3+, Eu3+ nanofibers display paramagnetism at ambient temperature. The as-synthesized Gd2O2S:Dy3+, Eu3+ nanofibers have applicable prospects in anti-fake, lasers, modulator, liquid crystal display, drug delivery and light emitting diodes (LEDs) due to their magnetism-photoluminescence dual-functionality.

Ratiometric determination of copper(II) using dually emitting Mn(II)-doped ZnS quantum dots as a fluorescent probe.

A ratiometric probe is described for the fluorometric determination of Cu(II) ions based on their quenching effect on the luminescence of dually-emitting quantum dots (QDs). ZnS QDs were doped with Mn(II) and subsequently modified with mercaptopropionic acid to give the QD probe which consists of a sole fluorophore but hastwo emission peaks (at 430 and 590nm under 310nm excitation, respectively). On addition of Cu(II) ions, the 590nm band is quenched while the 430nm band exhibits a little change. The changes in theintensity ratios of the yellow and the purple bands increases linearly in the 0 to 3.0μM Cu(II) concentration range, and the detection limit reached 14nM. The QD probe was validated and successfully applied to the determination of Cu(II) in spiked real water samples. Graphical abstract Mn-doped ZnS (ZnS:Mn(II)) quantum dots were synthesized with yellow fluorescence. After the modification of 3-mercaptopropionic acid (MPA), ZnS:Mn(II) was transferred to aqueous phase and became MPA modified Mn-doped ZnS (MPA- ZnS:Mn(II)). The fluorescence was changed to purple upon the addition of copper ions because the yellow band was largely quenched while the purple band only changed a little.

Homo-epitaxial growth of high crystal quality GaN thin films by plasma assisted–molecular beam epitaxy

Gallium nitride (GaN) films homo-epitaxially grown on GaN/sapphire templates and free standing GaN substrates by plasma-assisted molecular beam epitaxy (PA-MBE) have been investigated. After optimizations of growth temperature, the Ga/N flux ratio, surface preparation as well as initial growth process, the high quality MBE-GaN films were obtained. Combined with X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements, the TD densities were measured ∼4.2 × 108 cm−2 and ∼5 × 105 cm−2 for MBE-grown GaN films grown on GaN/sapphire templates and free standing GaN substrates, respectively. The observations of TEM prove the clear interface and well-arranged atomic lattice between substrates and as-grown layers. Besides, a flat and smooth surface with step-flow growth mode is observed by atomic force microscopy (AFM). Photoluminescence (PL) measurements exhibit that the linewidth for free excitons is as narrow as 4 meV at low temperature of 8 K and the deep level related yellow band emission ∼550 nm have been effectively suppressed at room temperature. The process optimization and obtained results give us wide latitude to fabricate high performance devices with lower tolerance to dislocation density.

Yellowish White-Light Emission Involving Resonant Energy Transfer in a New One-Dimensional Hybrid Material: (C9H10N2)PbCl4

The present work deals with a new one-dimensional (1D) organic–inorganic hybrid material, namely (C9H10N2)PbCl4 (abbreviated as AQPbCl4). Its crystal structure is built up from the infinite 1D chain of edge-sharing PbCl6 octahedra surrounded by 3-aminoquinoline (abbreviated as AQ) organic molecules. Contrary to the most organic–inorganic hybrid materials, where the organic moieties act as barriers and the inorganic parts play the role of quantum wells, both inorganic and organic parts in AQPbCl4 are optically active, giving rise to optical properties involving the competition and the interaction of two organic and inorganic emitting entities. Under UV excitation, this hybrid compound shows a strong yellowish white-light emission that can be seen even with the naked eye and at room temperature. The photoluminescence spectrum is composed of a strong and broad yellow band at 538 nm associated with π–π* transition localized within the AQ organic molecule and a less intense band in the UV region at 340 nm asso...

Deciphering Silicification Pathways of Fossil Forests: Case Studies from the Late Paleozoic of Central Europe

The occurrence and formation of silicified wood from five late Paleozoic basins in Central Europe was investigated. Fossil wood from diverse geological settings was studied using field observations, taphonomic determinations as well as mineralogical analyses (polarizing microscopy, cathodoluminescence (CL) microscopy and spectroscopy). The results indicate that silicification is either a monophase or multiphase process under varying physico-chemical conditions. In particular, CL studies revealed complex processes of silica accumulation and crystallization. The CL characteristics of quartz phases in silicified wood can mostly be related to blue (390 and 440 nm), yellow (580 nm), and red (650 nm) emission bands, which may appear in different combinations and varying intensity ratios. Yellow CL is typical for initial silicification, reflecting quick precipitation under oxygen-deficient conditions caused by initial decay of the organic material. Blue CL is predominantly of secondary origin, resulting from replacement of precursor phases by a secondary hydrothermal quartz generation or subsequent silicification of wood. The red CL can be related to a lattice defect (non-bridging oxygen hole center—NBOHC).

PORIFERAN ABUNDANCE IS NEGATIVELY ASSOCIATED WITH CORAL HEALTH IN THE MESOAMERICAN REEF

Abstract The Mesoamerican Reef is the second largest coral reef in the world and has experienced a 50% loss of coral coverage in recent decades. Due to the high biodiversity of marine life that depend on the Mesoamerican Reef, identifying drivers of coral loss is crucial. This study was designed to assess the relationship between the presence of yellow band disease (YBD) and white plague type-II (WPII) on stony corals with environmental (water depth) and biological stressors (abundance of sponges in close proximity) in the reef surrounding the Bay Islands, Honduras. Both radial and parallel transect survey techniques were used to quantify the abundance of seven sponge species within a one-meter radius of Orbicella species and Montastraea cavernsoa. The strongest predictor of coral health was the abundance of Callyspongia plicifera, followed by Svenzea zeai, in close proximity to diseased coral. A weak, but positive, correlation between poriferan abundance and the presence of disease lesions on coral was observed. However, no significant relationship of disease prevalence with water depth was observed. Additionally, no differences in the prevalence of disease lesions between four species of native stony corals were observed. These findings suggest coral species are equally susceptible to bacterial pathogens, but that close association with poriferans may increase the transmission and persistence of harmful bacteria in coral reef ecosystems.

Effects of Highlighting Text on the Reading Ability of Children with Developmental Dyslexia: A Pilot Study

Digital texts can be made accessible to children with developmental dyslexia by presenting them in a simplified layout, using suitable fonts, or using text highlighting that is synchronized with audio. However, the impact of this last method on readability (as measured by eye movement) for children with developmental dyslexia remains unknown; it is unclear whether the color and length of text highlighting influences readability. We examined these issues in two experiments with seven children with developmental dyslexia (aged 7–14 years). In the first experiment, we clarified the relation between readability and text highlighting with synchronous audio by measuring the eye movements of children with developmental dyslexia. Readability was determined using the frequency of eye fixations. In the second experiment, we determined which styles of text highlighting best supported digital text reading among children with developmental dyslexia. Digital texts were created using different text highlighting colors and band lengths, and then were read using Apple iBooks on a 9.7-inch Apple iPad Air. We observed that children with developmental dyslexia found it easier to read along when audio was synchronized with text highlighting, particularly for the highlighting style that used a blue band for whole sentences. The second experiment showed that children with developmental dyslexia found it particularly easy to read digital texts that were highlighted with blue or yellow bands, both for single sentences and for single words. The method of presenting visual information for reading might help children with developmental dyslexia read more easily.

Metastability effects on the photoluminescence of ZnO nano-micro structures grown at low temperature and influence of the precursors on their morphology and structure

Nanocrystalline ZnO films were grown on silicon substrate by hydrothermal synthesis at 125 °C, using diethanolamine as additive. A powder containing ZnO spheres, with diameters between 100 to 200 nm and formed by aggregation of ZnO nanoparticles, was also obtained as a secondary reaction product. The samples were studied by scanning electron microscopy, X-ray diffraction and photoluminescence (PL) spectroscopy. The effects of the [diethanolamine]/[Zn2+] molar ratio on morphological, structural and optical properties were studied, as well as the effect of laser illumination (λ = 325 nm) and annealing treatment on photoluminescence properties. The film samples exhibited a compact columnar structure, with thickness between 180 to 210 nm, which were not strongly affected by the diethanolamine concentration. The X-ray diffraction patterns from the films evidenced preferred orientation along the c-axis of the ZnO wurzite structure; while the nanospheres did not show any preferential crystalline direction. The PL spectra from the films showed large initial UV emission and a weak defect band centered in the yellow. A PL evolution while the samples were UV illuminated was observed. The relaxation of metastable phases (formed during the low temperature growth) involving the creation of point defects, is suggested. The predominance of the yellow defect band before and after treatment points at oxygen vacancies as the possible point-defect candidate.

The appearance of mimetic Heliconius butterflies to predators and conspecifics.

Adaptive coloration is under conflicting selection pressures: choosing potential mates and warning signaling against visually guided predators. Different elements of the color signal may therefore be tuned by evolution for different functions. We investigated how mimicry in four pairs of Heliconius comimics is potentially seen both from the perspective of butterflies and birds. Visual sensitivities of eight candidate avian predators were predicted through genetic analysis of their opsin genes. Using digital image color analysis, combined with bird and butterfly visual system models, we explored how predators and conspecifics may visualize mimetic patterns. Ultraviolet vision (UVS) birds are able to discriminate between the yellow and white colors of comimics better than violet vision (VS) birds. For Heliconius vision, males and females differ in their ability to discriminate comimics. Female vision and red filtering pigments have a significant effect on the perception of the yellow forewing band and the red ventral forewing pattern. A behavioral experiment showed that UV cues are used in mating behavior; removal of such cues was associated with an increased tendency to approach comimics as compared to conspecifics. We have therefore shown that visual signals can act to both reduce the cost of confusion in courtship and maintain the advantages of mimicry.

The Serine Protease Activity of Corin Is Required for Normal Pigment Type Switching

The Serine Protease Activity of Corin Is Required for Normal Pigment Type Switching

Reduction of yellow and blue luminescence in Si-doped GaN by rapid thermal annealing

Si-doped GaN films grown by metal organic chemical vapour deposition have been annealed under different annealing conditions in N2 ambient. The annealed films have been characterized by photoluminescence and high resolution X-ray diffraction. The results show that the rapid thermal annealing (RTA) treatment suppresses the yellow and blue luminescence bands in the annealed Si-doped GaN films. For the sample annealed at 850 °C for 3 min, the yellow and blue band intensities even decreases by approximate one order of magnitude over the as-grown sample. In addition, the densities of the edge and screw threading dislocations in the Si-doped GaN also decrease after the RTA treatment. These facts provide the evidence that the RTA technique can effectively improve the crystalline quality of the Si-GaN films.

Extremely Slow Decay of Yellow Luminescence in Be‐Doped GaN and Its Identification

The extremely slowly decaying yellow luminescence band around 2.08 eV in GaN:Be:O is studied by continuous‐wave and time‐resolved photoluminescence, as well as photoluminescence excitation spectroscopy and absorption. The lifetime obtained for this process is around 2.2 s and is thermally quenched for temperatures between 250 and 400 K. From the photoluminescence excitation measurements, two major pumping thresholds at around 2.7 and 3.1 eV can be identified. We discuss the origin of the Be‐related 2.08 eV transition as well as the origin of the overlaying photoluminescence bands at 1.88 and 2.12 eV.

Color temperature tunable of Dy3+-doped LaPO4 nanorods prepared via hydrothermal method for white LEDs applications

Nano-powders of La(1-x)DyxPO4 with rod-like morphology have been synthesized via hydrothermal method and characterized by X-ray diffraction, TEM, FTIR and Raman spectroscopy. The X-ray diffraction patterns collected for the prepared materials indicated the high purity of crystalline phase with a monoclinic structure. Photoluminescence properties have been investigated based on excitation and emission spectra, decay curves and chromatic coordinates. The emission spectra show a broad blue band ascribed to the transitions from the excited levels 4I11/2, 4I13/2, 4I15/2 and 4F9/2 to the fundamental levels 6H15/2. A yellow band related to the 4F9/2―›6H13/2 transition has been observed at 573 nm. The luminescence intensities ratio and lifetimes have been found to be dependent on the concentration of Dy3+ ion and the excitation wavelength. The decay curves present double exponential shape for all concentration of Dy3+. The yellow-to-blue emission intensity ratios and CIE chromaticity coordinates have been used to estimate the color of the emitted light. A high-quality of white light with three-color temperature (Warm, Natural or Daylight, Cool) has been obtained from a single emitting phosphor, LaPO4:Dy3+. The improved emission lifetimes and color temperature are suitable for application in the white light LED devices.

Tailored optical properties of Dy3+ doped magnesium zinc sulfophosphate glass: Function of silver nanoparticles embedment

Glasses with composition (59.5-x)P2O5–20.0MgO-20.0ZnSO4–0.5Dy2O3-xAgCl (0.0≤x≤ 0.5 mol%) were prepared by melt-quenching method and characterized thoroughly. The role of silver nanoparticles (Ag NPs) inclusion on the spectroscopic and the physical properties of the synthesized glasses were determined. Judd-Ofelt (J-O) theory was used to complement the experimental optical data. TEM images confirmed the existence of Ag NPs of average size ≈4.5 nm. The absorption spectra showed eleven bands aroused from the ground state (6I15/2) to various excited states transitions of dysprosium (Dy3+) ion. The surface plasmon resonance (SPR) peak of Ag NPs was probed around 446 nm. The calculated J-O parameter (Ω2) for the glass without Ag NPs incorporation was the highest, indicating the strong metal-ligand covalence bond. Irrespective of Ag NPs contents, the emission spectra of the studied glasses revealed two intense photoluminescence bands centered at 480 nm (blue: 4F9/2→6H15/2) and 574 nm (yellow: 4F9/2→6H13/2) accompanied by two very weak red bands positioned at 662 and 752 nm. The luminescence intensity of both blue and yellow band was enhanced by a factor of 2 and it was 1.5 fold for the red bands. This enrichment in the luminescence intensity was attributed to the Ag NPs mediated SPR effect and subsequent energy transfer from the Ag NPs to the nearsighted Dy3+ ions.

Nonpolar and semipolar ultraviolet multiple quantum wells on GaN/sapphire

The surface morphologies, anisotropic quality and optical properties of nonpolar and semipolar ultraviolet multiple quantum wells (MQWs) structures on GaN/sapphire deposited by metal organic chemical vapor deposition are investigated. The crystal planes of the MQWs are identified as nonpolar (112¯0) plane and semipolar (112¯2) plane by the 2θ−ω scan of high-resolution X-ray diffraction (HRXRD). The results of the atomic force microscope and scanning electron microscope show that the surface morphologies of nonpolar and semipolar MQWs structures have obvious differences. The X-ray rocking curves of nonpolar and semipolar MQWs on-axis diffraction planes by HRXRD demonstrate that the semipolar MQWs structure has a better crystalline quality and a weaker anisotropy of crystal quality than nonpolar MQWs structure. The temperature dependence photoluminescence (PL) spectra reveal that the nonpolar MQWs structure have a stronger yellow band than semipolar MQWs structure. Besides that, the PL spectra of nonpolar MQWs structure also show a blue-shift as temperature increases within a certain range, and then, when the temperature increases continuously, it turns to a red-shift. However, for the semipolar MQWs structure, only the red-shift is observed in PL spectra.

Carrier dynamics of InxGa1-xN/GaN multiple quantum wells grown on (-201) β-Ga2O3 for bright vertical light emitting diodes.

High-quality InxGa1-xN/GaN multi-quantum well (MQW) structures (0.05≤x≤0.13), are successfully grown on transparent and conductive (-201)-oriented β-Ga2O3 substrate. Scanning-transmission electron microscopy and secondary ion mass spectrometry (SIMS) show well-defined high quality MQWs, while the In and Ga compositions in the wells and the barriers are estimated by SIMS. Temperature-dependant Photoluminescence (PL) confirms high optical quality with a strong bandedge emission and negligble yellow band. time-resolved PL measurements (via above/below-GaN bandgap excitations) explain carrier dynamics, showing that the radiative recombination is predominant. Our results demonstrate that (-201)-oriented β-Ga2O3 is a strong candidate as a substrate for III-nitride-based vertical- emitting devices.

Two yellow luminescence bands in undoped GaN

Two yellow luminescence bands related to different defects have been revealed in undoped GaN grown by hydride vapor phase epitaxy (HVPE). One of them, labeled YL1, has the zero-phonon line (ZPL) at 2.57 eV and the band maximum at 2.20 eV at low temperature. This luminescence band is the ubiquitous yellow band observed in GaN grown by metalorganic chemical vapor deposition, either undoped (but containing carbon with high concentration) or doped with Si. Another yellow band, labeled YL3, has the ZPL at 2.36 eV and the band maximum at 2.09 eV. Previously, the ZPL and fine structure of this band were erroneously attributed to the red luminescence band. Both the YL1 and YL3 bands show phonon-related fine structure at the high-energy side, which is caused by strong electron-phonon coupling involving the LO and pseudo-local phonon modes. The shapes of the bands are described with a one-dimensional configuration coordinate model, and the Huang-Rhys factors are found. Possible origins of the defect-related luminescence bands are discussed.

Photoluminescence investigations on Dy3+ ions doped Zinc Lead Tungsten Tellurite glasses for optoelectronic devices

Dy3+ doped Zinc Lead Tungsten Tellurite (ZnPbWTe) glasses have been synthesized by conventional melt quench method and their luminescence behavior was analyzed using optical absorption, excitation, photoluminescence (PL) and PL decay spectral studies. The Judd-Ofelt (J-O) intensity parameters evaluated from the absorption spectra are used to determine various radiative parameters such as transition probability (AR), branching ratio (βR) and radiative lifetimes (τR) for the prominent emission transitions of Dy3+ions in ZnPbWTe glasses. Under 384 nm excitation, PL spectra recorded for the titled glasses, exhibit two intense peaks; one in yellow at 575 nm and the other one in blue at 483 nm region. Among these two, yellow band (4F9/2 → 6H13/2) is relatively more intense than the blue one (4F9/2 → 6H15/2). The intensity of PL spectra increases up to 1 mol% of Dy3+ ions in ZnPbWTe glasses and beyond concentration quenching is observed. Branching ratios (βR) and emission cross-sections (σse) were estimated for 4F9/2 → 6H13/2 transition to understand the potential utility of these glasses for laser action in visible region. The CIE chromaticity coordinates, color correlated temperature (CCT), color purity and Y/B ratios were also estimated to understand the suitability of these glasses for w-LEDs. The luminescence quantum efficiency evaluated for the titled glasses showing highest value for 1 mol% of Dy3+ ions present in the as prepared glasses. From the measured emission cross-sections, quantum efficiency and CIE coordinates, it was observed that 1 mol% of Dy3+ ions in ZnPbWTe glasses are aptly suitable for optoelectronic devices such as lasers and w-LEDs.