CIE Chromaticity Diagram Research Articles

Enhancement of luminescence and thermal stability in Eu3+-doped K3Y(BO2)6 with Li+ and Na+ co-doping

Eu3+-doped and Li+/Na+ co-doped K3Y(BO2)6 (KYBO) phosphors were synthesized through a microwave-assisted sol–gel method, and their structural and photoluminescent (PL) characteristics were examined. X-ray diffraction (XRD) and Rietveld refinement confirm effective dopant incorporation and preservation of the crystalline structure. Fourier Transform Infrared (FTIR) spectroscopy indicates the maintenance of the borate structure, confirming the structural integrity of the phosphors upon doping. The addition of Li+ and Na+ co-dopants notably enhances luminescent efficiency and thermal stability, making these phosphors promising candidates for solid-state lighting (SSL) applications. PL analysis reveals strong red emission peaks at 612 nm, attributed to the 5Do → 7F2 transition of Eu3+ ions. The study indicates that electric dipole-quadrupole interactions are the primary mechanism for energy migration, with a critical distance of approximately 22.68 Å. This mechanism contributes to concentration quenching at higher doping levels. High temperature PL measurements indicated an activation energy of 0.1389 eV for thermal quenching in the Li+ co-doped sample. Additionally, the Na+ co-doped sample exhibited an abnormal thermal stability behavior, with an even higher activation energy of 0.2536 eV. This suggests that Na+ co-doping significantly enhances the thermal resilience of the phosphor, making it more suitable for high-power light-emitting applications that operate under extreme conditions. CIE chromaticity diagrams highlight the potential for optimizing Eu3+ doping levels, combined with Li+ and Na+ co-doping, to improve luminescent performance and thermal stability for advanced SSL applications.

Up-conversion materials for solid-state lighting

AbstractConventional phosphor-converted white LEDs (WLEDs), using (Stokes) down-conversion light emission, suffer from a red deficiency that increases the Color Temperature towards “cool white light” above 5000 K. The present work describes a phosphor-Up-converted WLED approach that wishes to overcome this issue by achieving white light generation (WLG) through Up-conversion photoluminescence (UCPL), without energy losses due to Stokes shift and excited by a 980 nm LED instead of the more expensive blue LEDs. The UC materials include thin films of lanthanide (Ln)-doped aluminosilicate glass multilayers, alternating (Ln)-doped aluminosilicate and titania films in the form of 1-D photonic crystals and Ln ion-implanted materials. Sol-gel (SG) processing has been used as a low-cost high purity processing method to prepare titania, as well as aluminosilicate films containing Er3+, Tm3+ and Yb3+, for WLG and possible application as WLED materials. The total Ln content varied from a high of 22 mol% to as low as 5.8 mol%. The materials prepared have been characterized by UV-Vis-NIR (using a variable angle specular reflection accessory), plus FTIR and UCPL spectroscopies. The UC light emission was analyzed with the help of CIE chromaticity diagrams. Graphical abstract

Plasma coloring of Ti via air atmospheric pressure plasma jet for dentistry

The aesthetic appeal of titanium dental implants is compromised by unattractive coloration, and extended exposure to bodily fluids can result in the release of ions, potentially causing infection or inflammation. This study introduces a direct method for oxidizing titanium through plasma coloring to enhance biocompatibility. Utilizing a tornado-type atmospheric pressure plasma jet (APPJ) with compressed dry air as the working gas, sub-stoichiometric titanium oxide was produced on sample surfaces. Analysis of reactive oxygen species (ROS) in air plasma via optical emission spectroscopy offers valuable insights into the interaction between plasma and the surface during the oxidation process. Quantification of surface coloration in titanium samples before and after treatment with air-APPJ was conducted using CIE chromaticity diagrams and color temperature analysis. This analytical approach enabled the assessment of thermal and plasma-chemical impacts of plasma coloring on the development of the sub-stoichiometric titanium oxide layer. The resulting oxide layers from the APPJ process exhibited a vibrant golden shade, along with enhanced surface hydrophilicity, improved anticorrosion properties, and enhanced cellular responses.

Photoluminescence Quenching in Metal Doped Graphitic Carbon Nitride: Possibilities Toward Metal Sensors

AbstractThe present work describes the synthesis of graphitic carbon nitride (GCN) via simple two‐step thermal decomposition of urea at a moderate temperature of 550 °C. The as‐synthesized GCN is further doped with transition metals like nickel, and both the pure and doped GCN are characterized by X‐ray diffraction (XRD), field emission scanning electron microscope (FESEM), X‐ray photoelectron spectroscopy (XPS), and Fourier transformed infrared (FTIR) spectroscopy. XRD shows the perfect phase formation in the pure GCN, which also remains in the doped sample but with much lesser crystallinity. FESEM shows that after doping, the small chips‐like structure of GCN gets transformed to an elongated one. XPS confirms the successful doping by keeping the signature of both nickel 2P1/2 and 2P3/2 oxidation states in the spectra, whereas FTIR gave an idea about different bonding present in the sample. The pure sample, when irradiated with an excitation wavelength of 350 nm, gives an intense peak at 457 nm, which gets considerably quenched in the case of the doped sample. However, a new peak appears in the photoluminescence (PL) spectra of the doped sample at 624 nm. The quenching of PL intensity in the doped sample is assumed to be due to the fact that the dopant‐induced state traps the electron, hindering them from immediate recombination. This quenching of PL intensity generates the possibilities of sensing the presence of different metals and thus taking measurable steps for removing them. The CIE chromaticity diagrams for the doped and undoped samples confirm that the emission color changes from blue to cyan region after the doping.

Investigating the Structural, Linear/Nonlinear Optical, and Photoluminescence Characteristics of CuO/ZnMn2O4 Nanocomposite for Physicochemical Applications

The structural, optical, and photoluminescence performance of CuO/ZnMn2O4 nanocomposites was investigated for optical applications. Nanocomposites of xCuO/(1-x)ZnMn2O4 (x; 0 to 0.7) were equipped using the sol-gel route. Synchrotron X-ray diffraction data were collected to examine the structural parameters. Rietveld refinement analysis reveals that the crystallite size decreases upon raising x from 0 to 0.7. High-resolution transmission electron microscopy revealed that the distribution of particle sizes demonstrates a relatively broad spectrum within the nanometer range. Raman spectroscopy investigations were applied to examine the structure’s vibrations. Scanning electron microscopy was used to examine the morphology of the formed samples. UV–vis spectrophotometry was applied to collect optical absorbance and reflectance measurements of the samples. Optical energy gap E g was determined utilizing the Kubelka-Munk method. The refractive index investigations were explored based on seven empirical formulas. The nonlinear optical parameters were explored as a function of CuO contents. The influence of CuO amount on the photoluminescence spectra was investigated. CIE chromaticity diagrams showed that all samples have various degrees of blue-violet colors. A significant improvement was achieved in the linear/nonlinear optical performance of nano ZnMn2O4 by forming CuO/ZnMn2O4 heterojunction, supporting the possible use of CuO/ZnMn2O4 nanocomposites in various optical applications.

An extensive inquisition on the impact of modifier oxides over the luminescent properties of Eu3+ embedded Li-Al tri-former glasses for photonic applications

A novel, tri-former glasses with the composition 45B2O3+12P2O5+8SiO2+3Al2O3+10LiF+20MO+1Eu2O3 with varying metal oxides have been fabricated following the melt-quenching technique. The absorption, luminescence and radiative decay measurements were carried out, and the specific colour emitted by the glass sample was determined employing the CIE chromaticity diagram. While monitoring the excitation at 393 nm, luminescence spectra of all the glass samples exhibit red emission pertaining to the 5D0→7F2 transition at around 615 nm. The local geometry around the Eu3+ ions site and the nature of the Rare Earth ion-ligand bond have been analyzed employing Judd-Ofelt theory and the R/O ratio spectral parameter. The intensity parameters follows the trend as Ω2 > Ω4 > Ω6 and the results are co-related well with the R/O ratio spectral parameter values. Radiative properties such as σPE, βR and AR of every glass in the present series possess higher values, and the FWHM exhibits lower value, indicating the potentiality of the BPSAEu:M glasses for lasing applications. Among the prepared samples, BPSAEu:Ba glass exhibit higher values for σPE and AR as 42.3 × 10−22 cm2 and 641.71 s−1 respectively which are apt for laser applications. The quantum yield pertaining to the 5D0→7F2 transition exhibit more than 65 % for all the samples and particularly Barium oxide incorporated glass BPSAEu:Ba exhibits 84 %. The present study suggests that BPASEu:Ba glass is a promising luminescent material for photonic/LED applications.

Latent fingerprint detection and identification using yellow-emitting YOF:Pr3+ nanophosphor

In this study, YOF:Pr3+ nanophosphors were synthesized using the microwave-assisted hydrothermal route. The structural and morphological properties of the nanophosphors calcined at different temperatures were studied in detail to optimize the synthesis conditions. The visible region and near-infrared (NIR) photoluminescence (PL) properties of the nanophosphors were obtained. Intense emission bands were observed in the blue and red regions under 250 nm excitation. The CIE chromaticity diagram showed that the color coordinates of the nanophosphors were located in the yellow region. The optimum Pr3+-concentration was found to be 0.002 mol fraction. The application of YOF: 0.002 Pr3+ nanophosphor for latent fingerprint detection was examined and evaluated on different types of surfaces. The nanophosphor demonstrated excellent adherence to the ridge patterns and sufficient sensitivity required for distinguishing between the ridges and the furrows. Different levels of detail were also observed that provided necessary information for the individualization of the fingerprints. The results suggest that the prepared YOF:Pr3+ nanophosphor can be a potential candidate for the rapid visualization and detection of latent fingerprints.

Fabrication and characterization of blue nano ceramic-inks: Utilization of cobalt aluminate pigments prepared by solid state method

The current study focuses on the development and fabrication of ceramic nano inks with improved properties. Firstly, two types of pigments were prepared through a solid state process using fine gibbsite (Al(OH)3) or aluminum chloride (AlCl3) with cobalt chloride hexahydrate (CoCl2.6H2O). The stoichiometric precursors were well-mixed and fired at 1000oC; then milled by a high energy ball mill to obtain nano pigments. The prepared pigments were investigated for their phase composition and crystallite size by X-ray diffraction, and further confirmed by Fourier Transform Infrared (FTIR). The morphology and particle size were examined using a scanning electron microscope. The optical properties in terms of UV–Vis, photoluminence emission spectra and CIE chromaticity diagram were also tested. The chemical-state of cobalt and surface elemental composition of prepared Co-aluminate pigments were tested by X-ray photoelectron spectroscopy (XPS). Four groups of ceramic-inks (twelve formulations) were prepared using different percentages of cobalt aluminate pigments and additives. The fabricated inks were investigated for their morphology, rheology, contact-angle and sedimentation behavior. The results revealed that two cobalt aluminate pigments with spinel structure, nano sized particles and blue color, were successfully prepared by the proposed method. The results of optical properties indicated that the cobalt ions are located mainly in tetrahedral sites with a small amount in octahedral sites. The prepared pigments were successfully used in the fabrication of ceramic nano inks with improved properties. The viscosity of most fabricated inks was in the range needed for the industry (4–40 mPa s).

Ratiometric Fluorescence Depending on In/Out Isomerism of Host‐Guest Conjugate Having a Fluorosolvatochromic Dye

Host‐guest conjugate is a promising strategy for providing outstanding molecules. Herein, we designed host‐guest conjugate HG1, which comprises a hydrophilic host unit, tetraaza[2.2.1.2.2.1]paracyclophane CPX2with a microhydrophobic cavity, and a guest unit, 2,3‐naphthalimide fused with two benzothiophenes G1 exhibiting fluorosolvatochromism, linked with an oxyethylene chain. HG1 initially showed a fluorescence band at 585 nm in MeOH/H2O (1/499 v/v); however, this band decreased with time, and instead, a new band at 430 nm appeared. The CIE chromaticity diagram showed that the fluorescent color changed from yellow‐orange to blue via white. NMR analysis of HG1 in methanol‐d4 exhibited different signals of the G1 unit between the blue and yellow fluorescent structures. The blue fluorescent structures showed asymmetrical signals assigned as the G1 unit, affected by the cavity environment of the CPX2 unit. Consequently, HG1 can form two conformations: In‐form and Out‐form. In In‐form, the G1 unit is inside the hydrophobic cavity of the CPX2 unit and shows blue fluorescence. In Out‐form, the G1 unit is outside the CPX2 unit and shows yellow fluorescence in an aqueous solvent. Therefore, HG1 performs as a ratiometric fluorophore depending on the in/out isomerism of the host‐guest conjugate.

Influence of ZnMn2O4/CuCo2O4 nano-fillers on the optical and electrical properties PVA/CMC/PEG blended polymers

(1-x)ZnMn2O4/xCuCo2O4 samples were synthesized by the co-precipitation method while polyvinyl alcohol/carboxymethyl cellulose/polyethylene glycol (PVA/CMC/PEG) blended polymer were fabricated by the casting method. Rietveld refinement analysis was used to determine the crystallite size and phase percentages for each composition were determined for all samples. The morphology and structure of PVA/CMC/PEG/(1-x)ZnMn2O4/xCuCo2O4 blends were examined using scanning electron microscopy and x-ray diffraction techniques. The reflectance and transmittance spectra were examined for blended polymers using a diffused reflectance spectrophotometer. Using LCR meter, the prepared blend films' dielectric properties were evaluated. When the blend is loaded with 0.9ZnMn2O4/0.1CuCo2O4, the lowest transmittance values (29–47 %) in the visible region are reached. As the CuCo2O4 doping levels became 10 % in the filler, the smallest direct and indirect energy gap values of 5.4 and (4.47, 1.9, 1.65) eV were attained, respectively. The linear and nonlinear optical parameters affected by the amount of CuCo2O4 in the filler samples. The optical conductivity of the doped blend reached its maximum value at x = 0.15. The CIE chromaticity diagrams revealed that the blends have varying degrees of blue color. The addition of (1-x)ZnMn2O4/xCuCo2O4 fillers improves the energy storage capability of the blends without raising the energy dissipation. The highest value of AC conductivity was achieved with the blend containing 0.9ZnMn2O4/0.1CuCo2O4. Nyquist plot revealed that the ionic conductivity increased as a result of doping. The obtained results suggest that the doped PVA/CMC/PEG/(1-x)ZnMn2O4/xCuCo2O4 blends might be used in a variety of industrial applications, including solar cell technology.

The influence of raw material changes on gamut colour volume of a matt ceramic glaze

This study aims to investigate the relationship between digital printing colour performance and the raw materials used in a matt glaze. Inkjet technology has enhanced the decorative properties of ceramic tiles in production. Improving the colour perception of the glaze is possible by optimizing the raw materials in the glaze, which results in less ink usage and thus lower costs. Investigation of the colour performance of glazes is possible by determining the L* a* b* values of the colours as well as the gamut colour volumes. Colour of the samples were evaluated by spectrophotometer and i1 profiler. Gamut volume was calculated by 3D CIE chromaticity diagrams of ICC profiles. It was observed that the colour saturation was higher in the samples where the pigment was homogeneously distributed in the glaze microstructure. SiO2 particles not embedded in the glass structure observed in the glaze microstructure disrupt the colour intensity. The low sphere temperature value of the composition made with wollastonite enabled the SiO2 particles to be embedded in the glaze. When wollastonite was used instead of dolomite as the source of calcium oxide in mat glaze, the colour gamut volume reached its highest value (11262), consequently increasing colour saturation. Conversely, the lowest colour gamut volume (6475) was obtained when dolomite was used instead of wollastonite.

The Influence of CdS on the Structural and Optical Properties of Nano ZnWO4

We investigated the influence of CdS on the structural and optical properties of nano ZnWO4 for optical applications. (1−x)ZnWO4/xCdS (x; 0 to 0.25) heterojunctions were formed and the structure and microstructure of the ZnWO4 and CdS phases developed were investigated using Rietveld refinement analysis for synchrotron X-ray diffraction data. Phase analysis revealed the phase percentage of the CdS phase is always less than the nominated value (x), implying merging of some Cd and S into ZnWO4. Raman spectra showed CdS peaks, confirming the existence of CdS. Scanning electron microscopy showed two distinct morphologies: plate-like particles (ZnWO4 phase) and spherical shape (CdS phase). UV–vis diffuse measurements revealed enhancement of absorbance and reduction in reflectance and transmittance, in the range 300–56 nm, as the amount of CdS (x) increased in the (1−x)ZnWO4/xCdS system. Band gap of the ZnWO4 phase reduced from 4.0 eV for x = 0.0 to 3.9, 3.6, and 2.9 eV for x = 0.05, 0.1, and 0.25, respectively. The highest refractive index values were obtained as the amount of CdS reached 0.05. Impact of alloying on linear and nonlinear parameters and emitted photoluminescence spectra was studied. Upon loading ZnWO4 with CdS, the PL intensity is greatly quenched and the whole spectrum is red shifted, from 480 to 540 nm. CIE chromaticity diagrams show that ZnWO4 sample without any doping exhibits a blue color while the doped system reveals green-yellow colors.

Exploring the Structural, Optical and Photoluminescence Performances of CuCo2O4 and ZnMn2O4 Alloying

The performance of the structural, linear/ nonlinear optical and photoluminescent properties of CuCo2O4 and ZnMn2O4 alloying was investigated. (1−x)CuCo2O4/(x)ZnMn2O4 (x = 0, 0.10, 0.15, 0.2) samples were prepared by the sol-gel and hydrothermal procedures. Synchrotron X-ray diffraction measurements were employed to investigate the structural and microstructural properties applying the Rietveld refinement method. Fourier transform infraed and Raman techniques were applied to explore the structures’ variation and chemical bonding of the obtained phases. Ultraviolet–visible diffuse reflectance spectroscopy measurements were collected to explore the optical properties. The optical band gap values were determined using the Kubelka-Munk method. All samples exhibited two band gaps in the visible-NIR regions. Upon composing with ZnMn2O4, the band gaps of CuCo2O4 declined for x = 0.1 and 0.15, followed by an increase at x = 0.2. The possible electronic band structure of the samples and the photoluminescent performance of the prepared samples was investigated. The observed PL patterns manifest wide and asymmetrical emissions. The CIE chromaticity diagram for all samples was plotted. The obtained findings of (1−x)CuCo2O4/(x)ZnMn2O4 nominate their efficient role in optical device fabrication and photocatalyst applications.

Effect of metal chalcogenides on modifying the structural and optical properties of ZnWO4 nanostructure

Hydrothermal and thermolysis techniques were used to create ZnWO4 and 0.9ZnWO4-0.1MS (M = Cd, Zn, Pb) samples. The formed phases in each sample and their structure and microstructure were examined using Raman spectroscopy, Fourier-transform infrared spectroscopy and Rietveld refinement of Synchrotron x-ray diffraction data. The composition and morphology of the formed samples were investigated via scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS). The average crystallite size remains relatively constant regardless of the different metal chalcogenides. MS/ZnWO4 samples have two distinct morphologies. The UV diffuse reflectance spectroscopy (UV-DRS) technique is used to investigate the linear and nonlinear optical parameters for different samples. Alloying ZnWO4 with CdS or PbS affects the photo response region of the sample to include visible light. MS/ZnWO4 (MS=CdS, ZnS, PbS) samples have optical band gap values of 2.56, 2.43, 2.99 and 3.1 eV, respectively. The CdS/ZnWO4 and ZnS/ZnWO4 samples exhibit the highest refractive index and optical dielectric constant values within the visible range. CdS or PbS/ZnWO4 samples show the highest nonlinear optical parameters values within the visible range. The impact of MS samples on the photoluminescence emission of ZnWO4 was explored. The CIE chromaticity diagram reveals that MS/ZnWO4 (M = Zn and Pb) samples display a different degree of blue color while CdS/ZnWO4 sample reveals green-yellow colors.

Photo and X˗ray induced luminescences of Eu3+˗doped sodium alumino boro˗tellurite oxyfluoride scintillating glass for X˗ray detecting material

The spectroscopy features of sodium alumino boro˗tellurite oxyfluoride glasses doped with various molar fractions of Eu2O3 ions (TBANEu) are studied through absorbance, excitation, emission, and decay curves. The excitation data are used following phonon side band spectroscopy to evaluate the phonon energy (1326 cm-1) of the glass host. The densities, molar volumes, and refractive indices, including the Ω2,4,6 parameters of fabricated glasses are studied. The magnitudes of laser properties like effective line widths, branching ratios, and emission cross˗sections obtained for the Eu3+:5D0→7F2 transition could be useful for reddish-orange lighting devices application. Additionally the quantum efficiency estimated from experimental and calculated lifetimes is about ˃ 70% for the 5D0 level luminescence of TBANEu glasses. Upon 395 nm radiation, the current glass system can exhibit color coordinates close to (0.647, 0.351) for reddish˗orange light as performed by the CIE1931 chromaticity diagram. The integral scintillation intensities of TBANEu glasses were determined using the X˗ray excitation and observed that the TBANEu20 glass showed a highest scintillation efficiency of 39%, resulting in scintillator and X˗ray sensing device applications.

Colour gamut analysis of low‐cost dye‐sensitised solar cells using natural dyes

AbstractDue to the increasing effects of greenhouse gases and environmental pollution, the need for new clean energies like solar energy attracts much attention. Although the characteristics and the efficiency of green photovoltaic devices have been researched, the colour gamut achievable from those devices has not been studied. This study investigates the colour gamut of low‐cost dye‐sensitised solar cells (DSSCs). To do this, 14 natural dye extracts were obtained from herbal resources including dragon fruit, blueberry, mango, radish, yellow rose, red cabbage, sour pomegranate, beetroot, olive, green cabbage pepper, eggplant, parsley, bramble and cherry, and employed as photosensitiser in solar cells. Then, the colorimetric attributes of the photosensitisers were studied in three‐dimensional (3D)‐colour space, that is, CIELab, CIELCH and CIE1931 chromaticity diagram. Additionally, the convex hull method was employed to determine the colour gamut boundary and the corresponding colour gamut volume. Results showed that the majority of samples benefited from approximately 3°–82° of hue angle in a*b* diagram of CIELab colour space and showed the yellowish to reddish tint effects. In CIELCH colour order system, cherry and parsley showed the lowest and highest lightness attributes while the chroma property of samples varied from minimum 1.2 for eggplant to maximum 60.2 for the dragon fruit. Moreover, the results of using the convex hull method showed the volume of 7.73 × 104 that is bounded by the colour gamut of 3D colour points over the CIELab colour space.

Structural and Spectroscopic properties of Eu3+ doped SiO2–TiO2 nanoparticles for photonic applications

The Eu3+-doped TiO2 nanoparticles in sol gel silicate glasses of composition (80-x)SiO2 + 20TiO2 + 0.5xEu2O3, (SiTiEu) where x = 0.0 0.5, 1.5, 2.5 and 3.5 mol%, have been prepared by sol-gel technique. The glass samples were investigated by thermos-gravimetric analysis (TGA/DTA), ATR-FTIR, XRD, SEM, TEM, EDX, optical absorption and photoluminescence emission spectroscopy at room temperature (RT). The absorption wavelength of TiO2 doped sol-gel silicate glass were red shifted due to a reduction in band gap energy with increasing annealing temperatures. According to the TEM images, all of the particles were spherical and had an average diameter is around 10 nm. The visible spectra of the Eu3+ doped TiO2 nanoparticles in sol-gel silicate glasses displayed characteristic PL emission 5D0→7FJ (J = 0, 1, 2, 3, 4, 5) transitions of Eu3+ ions at 370 nm excitation. The anatase TiO2:1.5Eu3+ nanocomposite showed high photoluminescence emission at 370 nm excitation, which was attributed to the f-f transitions of Eu3+. The hypersensitive 5D0→7F2 transition was responsible for the major red emission. From the recorded spectra, radiative parameters and Judd-Ofelt (JO) intensity parameters were computed. The Eu3+ co-doped TiO2 nanoparticles in sol-gel silicate glasses displayed emissions mostly in the red regions realized from a CIE chromaticity diagram. The results suggested that materials may be used as an optical material of technological importance such as display devices and also for optical amplifier.

Efficient and tunable white light emitting from Sb3+, Tb3+, and Sm3+ Co-doped Cs2NaInCl6 double perovskite via multiple energy transfer processes

Inorganic lead-free double perovskites have the advantages of low toxicity, broadband emission, and good stability, which make them promising luminescent materials for lighting applications. However, due to the limited regulation of their self-trapped exciton emission, it is still greatly challenging to achieve white light emitting from a single double perovskite host. Herein, efficient and tunable white light is realized in Cs2NaInCl6: Sb3+, Tb3+, Sm3+ double perovskite by controlling the ratios of the doped three ions with blue, green, and red emissions, respectively. The steady-state and transient fluorescence spectra of singly- and doubly-doped double perovskites reveal the existence of multiple energy transfer channels in the triply-doped phosphors, including from Sb3+ to Tb3+, Sb3+ to Sm3+, and Tb3+ to Sm3+. Benefiting from these channels, the color coordinates of the triply-doped phosphors can cross the whole white light area of the CIE chromaticity diagram by adjusting the ratios of the three dopants, and the maximum internal quantum yield of the white light phosphors is 66.61 %. The white emission phosphors show the characteristic of being independent of excitation wavelength within 310–360 nm. Furthermore, the emission intensity at 430 K of the white light phosphor Cs2NaInCl6: 0.01Sb3+, 0.65Tb3+, 0.20Sm3+ remains 50 % of that at room temperature. A WLED device fabricated with the phosphor and a 365 nm LED chip exhibits a high color rendering index of 90.9, correlated color temperature of 5469 K, and CIE coordinates of (0.333 and 0.328). The results indicate that the as-prepared double perovskite materials are promising candidates in the solid-state lighting field.

Photoluminescence and supercapacitor applications of dysprosium doped rhombohedral silver gallium oxide nanoparticles

Dy3+ doped Silver Gallium Oxide (AgGaO2) nanoparticles (NPs) (AGO:Dy3+) are effectively synthesized via a green mediated route using Aloe vera gel extract as a reducing agent, followed by calcination at 600 °C for 3 h. Powder X-ray diffraction (PXRD), Fourier transformation infrared (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), photoluminescence (PL), and electrochemical studies were employed to confirm the synthesis, structural, luminescence, and supercapacitor properties of the NPs. The diffraction peaks of the synthesized samples possess a trigonal structure within a rhombohedral system. The surface morphology consists of a few irregular, a few hexagonal, and a few rice grain-structured NPs. The changes in the agglomeration were observed with variations in the dopant concentration. The direct energy band gap increases from 3.11 to 3.13 eV with an increase in the dopant concentration. Under 276 nm excitation, the PL spectra of AGO:Dy3+ nanophosphors reveal robust emission peaks attributed to 4F9/2→6F15/2 (480 nm) and 4F9/2→6F13/2 (565 nm). The confirmed critical distance signifies that energy transfer occurs through a multipolar interaction mechanism. The CIE chromaticity diagram illustrates the emission of yellowish green light from the phosphors. These investigations indicate the potential applications of AGO:Dy3+ nanocrystals in a light-emitting diode as a nanophosphor material. Nanocrystals in light-emitting diodes as a nanophosphor material. Thorough electrochemical investigations, encompassing cyclic voltammetry, were conducted to decipher redox reactions, electrode kinetics, and electrochemical behavior. The precise elucidation of ion transport kinetics was achieved through Electrochemical Impedance Spectroscopy (EIS), while the determination of supercapacitance values was accomplished via Galvanostatic Charge-Discharge (GCD) analysis. The supercapacitance values exhibited a remarkable range from 76.177 to 111.53 F/g, underscoring their sensitivity to dopant concentration. Consequently, the material synthesized in this groundbreaking study exhibits substantial promise for diverse applications, spanning from energy storage materials to the dynamic landscape of display technology. Electrochemical studies.

Optical Properties of Gd2O3 with Silver doped Zinc Borate Glasses

Glasses with chemical composition ZnO-B2O3-Gd2O3-Ag2O were prepared using melt quenching method. The synthesized glass was characterized using X-ray diffraction method. The densities of these glasses were measured using the Archimedes method, and the corresponding molar volumes were calculated using the corresponding formula. Absorption spectra were recorded using a UV-visible spectrometer. The energy bandgap was investigated using the Tauc’s diagram. The variation of band gap energy in relation to Gd2O3 concentration has been discussed. Study the structure and functional groups of the prepared samples were studied using FTIR spectra. Emission and excitation spectra were recorded using a luminescence spectrometer. Photoluminescence spectra provides stable blue light emission in rich in Gd2+ ions glass, Color coordination has also been decided using CIE chromaticity diagram and showing that blue emission was observed in all samples with slightly different positions.