Oxide Phosphors Research Articles

Greatly enhanced deep-red luminescence performance of Ca2InSbO6:Mn4+ phosphor via multiple optimization strategies

Phosphors with high luminescence intensity, thermal stability, and spectral matching are important for indoor plant cultivation (IPC) light-emitting diodes (LEDs). Mn4+ ion-doped phosphors are considered potential deep-red emitters for plant growth LEDs. Herein, Ca2InSbO6:Mn4+ (CISO:Mn4+) phosphors were first synthesized via high-temperature solid-phase method. Their luminescence performance was greatly enhanced by using three kinds of strategies (charge compensator, solid solution, and rare earth ion co-doping). Furthermore, the optimization mechanisms were studied in depth on the basis of the principle of charge compensation and reduced quenching centers. Surprisingly, the internal quantum efficiency of the Ca1·9Y0·1InSb0·6Ta0·4O6:0.006Mn4+ phosphor was greatly enhanced to 71.4%, which was 42.75 times that of the CISO:0.006Mn4+ phosphor. Under 373 nm excitation, the Ca1·9Y0·1InSb0·6Ta0·4O6:0.006Mn4+ phosphor showed intense deep-red emission at 695 nm attributed to the 2Eg→4A2g transition of Mn4+ ions, which indicated a good match with far red phytochrome (Pfr, 84%). Finally, the fabricated IPC-LED displayed superior spectral matching, color purity (99.9%), and CIE chromaticity coordinates (0.692, 0.308). Thus, it has great potential as deep-red substitutes in the field of IPC. This work adopted a series of comprehensive strategies to optimize the luminescence performance of Mn4+-doped oxide phosphors and discussed the optimization mechanisms in depth, aiming to provide new ideas for the future optimization of phosphors.

Near-Infrared Light-Emitting Diodes utilizing a Europium-Activated Calcium Oxide Phosphor with External Quantum Efficiency of up to 54.7.

Near-infrared (NIR) luminescence materials with broadband emissions are necessary for the development of light-emitting diodes (LEDs) based light sources. However, most known NIR-emitting materials are limited by their low external quantum efficiency. This work demonstrates how the photoluminescence quantum efficiency of europium-activated calcium oxide (CaO:Eu) NIR phosphor can be significantly improved and stabilized at operating temperatures of LEDs. A carbon paper wrapping technology is innovatively developed and used during the solid-state sintering to promote the reduction of Eu3+ into Eu2+ . In parallel, the oxygen vacancies in the CaO lattice are repaired utilizing GeO2 decomposition. Through this process, a record-high external quantum efficiency of 54.7% at 740 nm is obtained with a thermal stability greatly improved from 57% to 90% at 125°C. The as-fabricated NIR-LEDs reach record photoelectric efficiency (100 mA@23.4%) and output power (100 mA @ 319.5 mW). This discovery of high-performance phosphors will open new research avenues for broadband NIR LED light sources in a variety of photonics applications.

Near-Infrared Light-Induced Photoresponse in Er3+/Li+-Codoped Y2O3/Poly(methyl methacrylate) Composite Film.

We demonstrate Li+-doping engineering for improving the near-infrared (NIR) photoresponse in an Er3+-activated Y2O3 phosphor. We show that the rational incorporation of Li+ results in a large enhancement of the upconversion (UC) emission intensity up to 29 times upon excitation of NIR light. The improved UC properties could be associated with the enhanced dipole-dipole transition probability due to Li+-induced changes in the local site symmetry for Er3+ ions and improvement in the crystallinity of the samples. We further demonstrate the construction of UC phosphor/polymer composite films by attaching the UC phosphor/polymer composite film onto a Si-photoresistor. The device shows a large enhancement of the photovoltage response from 0.16 to 0.4 V in Li-doped samples under NIR light illumination. These results suggest an effective doping strategy for the improvement of the UC performance of the oxide phosphor and its wide applications in solar energy utilization and NIR response devices.

Eu2+ Doping Concentration-Induced Site-Selective Occupation and Photoluminescence Tuning in KSrScSi2O7:Eu2+ Phosphor.

Regulation of Eu2+ dopants in different cation sites of solid-state materials is of great significance for designing multicolor phosphors for light-emitting diodes (LEDs). Herein, we report the selective occupation of Eu2+ for multiple cationic sites in KSrScSi2O7, and the tunable photoluminescence from blue to cyan is realized through Eu2+ doping concentration-dependent crystal-site engineering. Eu2+ preferably occupies the K and Sr sites in KSrScSi2O7 at a low doping concentration, resulting in a 440 nm blue emission. As the Eu2+ concentration increases, a new Eu2+ substitution pathway is triggered, that is, Eu2+ enters the Sc site, leading to the red-shifted emission spectra from 440 to 485 nm. The doping mechanism and photoluminescence properties are corroborated by structural analysis, optical spectroscopy study, and density functional theory calculations. The optical properties of the as-fabricated white LEDs are studied, which demonstrates that these phosphors can be applied to full-spectrum phosphor-converted LEDs. This study provides a new design strategy to guide the development of multicolor Eu2+-doped oxide phosphors for lighting applications.

Site Preference-Driven Mn4+ Stabilization in Double Perovskite Phosphor Regulating Quantum Efficiency from Zero to Champion.

The tetravalent-state stability of manganese is of primary importance for Mn4+ luminescence. Double perovskite-structured A2B'B″O6:Mn4+ has been recently prevalent, and the manganese ions are assumed to substitute for the B″(IV-VI)O6 site to stabilize at the tetravalent charge state to generate far-red emissions. However, some Mn-doped A2B'B″O6-type materials show no or weak luminescence such as typical Ca2MgWO6:Mn. In this work, a cation-pair co-substitution strategy is proposed to replace 2Ca2+ by Na+-La3+ to form Ca2-2xNaxLaxMgWO6:Mn. The significant structural distortion appears in the solid solution lattices with the contraction of [MgO6] but enlargement of [WO6] octahedron. We hypothesize that the site occupancy preference of Mn migrates from Mg2+ to W6+ sites. As a result, the effective Mn4+/Mn2+ concentration enhances remarkably to regulate nonluminescence to highly efficient Mn4+-related far-red emission. The optimal CaNa0.5La0.5MgWO6:0.9%Mn4+ shows an internal quantum efficiency of 94% and external quantum efficiency of 82%, reaching up to the top values in Mn4+-doped oxide phosphors. This work may provide a new perspective for the rational design of Mn4+-activated red phosphors, primarily considering the site occupancy modification and tetravalent-state stability of Mn.

Co-substitution strategy to achieve a novel efficient deep-red-emitting SrKYTeO6:Mn4+ phosphor for plant cultivation lighting

Mn4+-doped oxide phosphors with bright red emission show promising application potential in plant cultivation lighting. However, finding suitable oxide hosts for Mn4+ ions incorporation is still a challenge. Herein, an efficient deep-red-emitting SrKYTeO6:Mn4+ phosphor was achieved through the co-substitution of [K+−Y3+] for [Sr2+−Ca2+] in non-luminous Sr2CaTeO6:Mn4+ for the first time. Crystal structure analysis reveals that the new SrKYTeO6 compound is isostructural to Sr2CaTeO6, which belongs to the monoclinic P21/n (14) space group. Upon 338 nm excitation, the SrKYTeO6:Mn4+ phosphor exhibits a deep-red emission band peaking at 680 nm, resulting from the 2Eg → 4A2 g transition of Mn4+ ion. The concentration of Mn4+ ion in SrKYTeO6 is optimized to be 0.4 mol%, and color purity and internal quantum efficiency (IQE) of this phosphor reach as high as 98.5% and 44.3%, respectively. The phosphor also possesses good thermal stability with the emission intensity at 423 K maintaining 56% of the initial value at 298 K. These superior luminescent properties could be attributed to the change of local crystal environment induced by distorting the internal [TeO6] octahedra. This work not only acquires an efficient SrKYTeO6:Mn4+ phosphor for application in plant cultivation lighting but also offers a replicable strategy for further exploring novel Mn4+-doped perovskite phosphors.

Nitridated CaSiO3: Eu and SrSiO3: Eu phosphors for LEDs

Eu2+-activated single-phase CaSi(O,N)3 and SrSi(O,N)3 oxonitridosilicate phosphors were synthesized by a conventional solid-state reaction method at 1100 °C and 1200 °C. For comparative purposes, their oxide equivalents, CaSiO3 and SrSiO3, doped with Eu2+ were obtained using the same synthesis method. The XRD patterns for the obtained phosphors indicate the formation of single-phase oxide and oxynitride phosphors. Energy Dispersive Spectroscopy (EDS) confirmed the incorporation of nitrogen in the phosphor host lattices. The formation of Ca/Sr-N and Si-N bonds can be observed in the FT-IR spectra. The oxonitridosilicate phosphors showed intense emission from Eu2+ in the green-red spectral region. The emissions were redshifted compared to their oxide counterparts described in the scientific literature. The thermal stability and quantum yields (QY) of oxonitridosilicate phosphors were significantly improved compared with respective oxide phosphors. This shows the high potential of oxynitrides as phosphors for light-emitting diodes (LEDs).

The effects of precursor concentration and morphology on photoluminescence behavior of Tb2O3 phosphors

AbstractTerbium oxide (Tb2O3) phosphors were prepared the using sol‐precipitation method with the use of different precursor concentrations. The X‐ray diffraction (XRD) patterns showed C‐type body‐centered cubic phase, space group Ia‐3, and the crystallite size values were found in the range of 19.45–32.34 nm depending on the solution composition and calcination temperature. As the crystallinity increased, the defects in the structure decreased, that is, the dislocation density decreased. Under the excitation at 325 nm, although all the Tb2O3 phosphors emitted a single peak around 544 nm (5D4‐7F5 transition) in PL spectra, when the peak was enlarged, the presence of additional peaks shifted to the red/blue region was also observed. The color chromaticity coordinates showed that it exhibited different tones of emission from light yellow to green depending on the precursor concentration and calcination temperature. With increasing the precursor concentration, nucleation rate increased and the particle shape changed from nearly spherical to rod‐like. They may be promising for laser devices and display applications due to their strong green emission.

Visible-light excited polar Dion-Jacobson Rb(Bi1-xEux)2Ti2NbO10 perovskites: photoluminescence properties and in vitro bioimaging.

Rare-earth ion-activated oxide phosphors are beneficial to overcome problems like photobleaching, reduced lifetime, and the blinking of organic dyes and quantum dots for bioimaging applications. In this work, we report that the phosphors Rb(Bi1-xEux)2Ti2NbO10 (0.025 ≤ x ≤ 0.2) exhibit an electric dipole moment induced sharp 5D0 → 7F2 transition upon blue light excitation with a luminescence lifetime of ∼1 ms. While the major drawback of Eu3+ activated compounds is the requirement of harmful UV excitation, interestingly, this solid solution exhibits a sharp and intense excitation peak at 465 nm (visible light) compared to 363 and 395 nm (UV region), making it viable for bioimaging applications. The sample with x = 0.125 reveals the highest emission intensity with a quantum yield of 10.5%. Temperature-dependent emission spectra of the sample (x = 0.125) reveal excellent thermal stability. The low cytotoxicity of this compound is confirmed by incubation in HeLa cells and SH-SY5Y neuroblastoma cells. The biocompatibility of the compound with SH-SY5Y and HEK293 cells was imaged via two-photon microscopy, indicating its potential for biomedical applications.

Tunable concentration/excitation-dependent deep-red and white light emission in single-phase Eu2+-activated Sc-based oxide phosphors for blue/UV-LEDs

Novel Sr3Sc4O9:xEu phosphors with tunable luminescence are firstly reported. All experimental results suggest the utilization potentiality of the multifunctional Sr3Sc4O9:xEu phosphors in agricultural and full-spectrum general lighting.

Characterization and thermoluminescence study of gamma irradiated Tb-doped ZnO and undoped ZnO synthesized by spray pyrolysis method

High gamma dose-resistant undoped ZnO and Tb-doped ZnO thermoluminescent (TL) micro-phosphors were prepared by the spray pyrolysis method. Scanning electron microscopy shows crystalline rods with hexagonal morphology, (0.1-0.4 µm diameter, and about 1 µm length). Raman spectra dispersion reveals a würtzite form. Photoluminescence (PL) study of irradiated zinc oxide films indicates the generation of defects produced by gamma irradiation resulting in an increased probability of electron-hole exciton recombination. PL spectrum shows emission bands from 5D4-7Fj=6,5,4,3 transitions ascribed to Tb3+ dopant in zinc oxide phosphor. X-ray diffraction patterns for both types of films growth (undoped ZnO and Tb-doped ZnO) are typical of zinc oxide crystalline structure, with no noticeable effect of Tb ions. Dosimetric properties, for both samples, show a low TL fading signal and TL reproducibility signal for undoped ZnO and Tb-doped ZnO samples was 29 and 57 %, respectively. The kinetic parameters such as activation energy E, frequency factor s, and Rm values, were obtained by Computerized Glow Curve Deconvolution (CGCD) assuming Mixed Order Kinetic model (MOK). The results show that the MOK well described the glow curves of zinc oxide films. The heating rate effects produced a broadening of glow peak located at 420 K. For purposes like radiation detector, atomic effective number (Zeff) was obtained: 27.74 and 56.47 for undoped ZnO and Tb-doped ZnO samples, respectively. The samples were exposed to gamma radiation in a wide range of 0.25–20 kGy dose. TL properties of undoped ZnO and Tb-doped ZnO samples show that these materials could be used to detect high doses in a gamma radiation field.

Development of Mechanically Reliable and Transparent Photochromic Film Using Solution Blowing Spinning Technology for Anti-Counterfeiting Applications.

Photochromic materials have attracted broad interest to enhance the anti-counterfeiting of commercial products. In order to develop anti-counterfeiting mechanically reliable composite materials, it is urgent to improve the engineering process of both the material and matrix. Herein, we report on the development of anti-counterfeiting mechanically reliable nanocomposites composed of rare-earth doped aluminate strontium oxide phosphor (RESA) nanoparticles (NPs) immobilized into the thermoplastic polyurethane-based nanofibrous film successfully fabricated via the simple solution blowing spinning technology. The generated photochromic film exhibits an ultraviolet-stimulated anti-counterfeiting property. Different films of different emissive properties were generated using different total contents of RESA. Transmission electron microscopy was utilized to investigate the morphological properties of RESA NPs to display a particle diameter of 3–17 nm. The morphologies, compositions, optical transmittance, and mechanical performance of the produced photochromic nanofibrous films were investigated. Several analytical methods were employed, including energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared spectrometry. The fibrous diameter of RESA-TPU was in the range of 200–250 nm. In order to ensure the development of transparent RESA-TPU film, RESA must be prepared in the nanosized form to allow better dispersion without agglomeration in the TPU matrix. The luminescent RESA-TPU film displayed an absorbance intensity at 367 nm and two emission intensities at 431 and 517 nm. The generated RESA-TPU films showed an enhanced hydrophobicity without negatively influencing their original appearance and mechanical properties. Upon irradiation with ultraviolet light, the transparent nanofibrous films displayed rapid and reversible photochromism to greenish-yellow without fatigue. The produced anti-counterfeiting films demonstrated stretchable, flexible, and translucent properties. As a simple sort of anti-counterfeiting substrates, the current novel photochromic film provides excellent anti-counterfeiting strength at low-cost as an efficient method to develop versatile materials with high mechanical strength to create an excellent market as well as adding economic and social values.

Linking Macro- and Micro-structural Analysis with Luminescence Control in Oxynitride Phosphors for Light-Emitting Diodes

Eu2+-doped UCr4C4-type oxynitride phosphors are emerging innovative materials to replace oxide and nitride phosphors for high-end light-emitting devices. However, the synthesis of high-purity phosphors and controlling the O/N ratio remain challenging. Here, we synthesized a series of Sr0.98Li2.5 + zAl1.5 – zO3 + 2zN1 – 2z:0.02Eu phosphors by precursor engineering, and these products showed an unexpected redshift from 583 to 620 nm. Joint refinement combining synchrotron X-ray diffraction and neutron powder diffraction was conducted to determine macro-structural properties. Extended X-ray absorption fine structure spectra revealed the micro-structural properties around the luminescent centers. The effects on photoluminescence from the first-shelled O/N ligands and the second-shelled Li/Al ions were demonstrated in detail. Finally, the light-emitting diode packages constructed using our phosphor revealed higher luminous efficiency of radiation and luminous efficacy than the SrLiAl3N4:Eu comparator. This study provided the basis for developing novel oxynitride phosphors and insights into the structural analysis from the macro and micro perspectives.

An efficient far‐red emission Sr2InSbO6:Mn4+, M (M = Li+, Na+, and K+) phosphors for plant cultivation LEDs

AbstractHigh‐efficiency and far‐red light phosphors based on Mn4+‐doped inorganic luminescence materials are beneficial to plant cultivation. However, Mn4+‐doped oxide phosphors have a common problem of low quantum efficiency. Alkali metal ion codoping can effectively improve the luminescence properties of Mn4+‐activated oxide phosphors. Herein, a series of Sr2InSbO6:Mn4+, M (SISO:Mn4+, M) (M = Li+, Na+, and K+) far‐red‐emitting phosphors codoped alkali metal ions were first synthesized. Density functional theory calculation indicated that SISO is a kind of indirect bandgap material with a bandgap of ∼1.60 eV. The SISO:Mn4+ samples showed a far‐red light at 698 nm upon 365 nm, which perfectly matched the absorption spectrum of the far‐red‐phytochrome (Pfr) of plants. The doping concentration of the SISO:Mn4+ samples was optimized to be 0.006 mol. The concentration quenching mechanism was defined as dipole–dipole interaction by combining the Dexter theory and the Inokuti–Hirayama model. Optimizing the sintering temperature and codoped with alkali metal ions (Li+, Na+, and K+) could improve the luminescent intensity of SISO:Mn4+. The optimum sintering temperature was 1300°C. The internal quantum efficiencies of SISO:0.006Mn4+ and SISO:0.006Mn4+, 0.006Li+ phosphors are 22.67% and 60.56%, respectively. SISO:Mn4+, Li+ phosphors‐based plant growth light‐emitting diodes (LEDs) demonstrate excellent optical stability and long lifetime. Thus, these phosphors are promising candidates for plant cultivation LEDs.

A highly efficient red emitting phosphor with enhanced blue-light absorption through a local crystal field regulation strategy

Mn4+-doped oxide phosphors with emission in deep-red region are promising for the application of plant cultivation lighting. However, it remains a great challenge to synthesize these phosphors with high blue-light absorption efficiency, which is pivotal for their practical commercial applications. Herein, we conducted a local crystal field regulation strategy to notably improve the luminescent property of the Mg14Ge5O24:Mn4+ phosphor. For instance, by introducing F- ions into the host, the absorption efficiency in blue-light region increased remarkably from 13% to 28%. By further substitution of Ti4+ for Ge4+ ions, the absorption efficiency further increased to 50%. Meanwhile, the achieved internal photoluminescence quantum yield is up to 92% for the Mg28Ge5.42Ti2O38F10:Mn4+ phosphor under 422 nm blue-light excitation. Besides, the phosphor exhibits excellent photoluminecence thermal stability, i. e., the emission intensity at 423 K retained 96% of that at room temperature. By means of X-ray absorption near-edge structure and extended X-ray absorption fine structure analysis, the effect of introducing F- and Ti4+ ions on the local coordination and valence of Mn ions in the hosts and the luminescent property of the phosphors are discussed in detail. Finally, LEDs were packaged by combining blue diode chips and Mg28Ge5.42Ti2O38F10:Mn4+ phosphor, and their validity for promoting growth of plants were successfully demonstrated.

Achieving highly efficient far-red emission from luminescence-ignorable Ca2MgTeO6:Mn4+ to Ca2-zLnzMgTe1-yWyO6:Mn4+ (Ln = La, Y, Gd) phosphors via solid solution and impurity doping strategies

The Mn4+-doped Ca2MgTeO6 (CMTO) far-red emitting phosphors with double perovskite-type structure were successfully synthesized. Upon near-ultraviolet (n-UV, 300 nm) light excitation, the as-prepared phosphors showed far-red light at 700 nm attributed to the 2Eg→4A2g transition of Mn4+ ion. The doping concentration of the CMTO:xMn4+ samples was optimized to be 0.8 mol%. The relevant mechanism of concentration quenching was demonstrated as the dipole-dipole interaction. Furthermore, solid solution and impurity doping strategies were adopted to improve the far-red emission of the luminescence-ignorable CMTO:Mn4+ phosphor. Series of Ca2MgTe(1−y)WyO6:0.8 mol%Mn4+ (y = 0–100 mol%) solid solution and Ca2−zLnzMgTe0.6W0.4O6:Mn4+ (Ln = La, Y, and Gd, z = 10 mol%) phosphors were synthesized through the above two strategies. The luminescence intensity of the optimal Ca1.9Gd0.1MgTe0.6W0.4O6:Mn4+ phosphor was 13.7 times that of the CMTO:Mn4+ phosphor and 2.51 times that of red commercial phosphor K2SiF6:Mn4+. Notably, both CMTO:Mn4+ and Ca1.9Gd0.1MgTe0.6W0.4O6:Mn4+ phosphors exhibited remarkable thermal stability compared with most Mn4+-doped phosphors. Finally, the highly efficient Ca1.9Gd0.1MgTe0.6W0.4O6:Mn4+ phosphor was successfully applied in fabricating the warm white light diode (w-LED). This working along both lines strategy exhibited great potential for luminescence optimization of Mn4+-doped oxide phosphors.

Investigation on Anomalous Thermal Quenching of Mn4+ Luminescence in A2XF6:Mn4+

Studying luminescence properties of phosphor materials is not only of scientific interest, but also technological importance. Here, we investigate luminescence intensity as a function of temperature for Mn4+-activated fluoride and oxide phosphors. A recent study suggested that an anomalous increase in Mn4+ luminescence intensity (I PL) with increasing lattice temperature (T) in various fluoride phosphors is likely a pitfall caused by a diminishment in the optical path lengths of the spectrofluorometer stemming from lattice thermal expansion. We show that such anomalous enhancement of I PL is due to the increased phonon number that makes it possible to gain the parity and spin-forbidden 2 E g → 4 A 2g transitions rather than an extrinsic effect of lattice thermal expansion. The temperature dependence of the zero-phonon line emission intensity I ZPL may be a good indicator for deciding whether an observed anomaly of I PL is due to an intrinsic or an extrinsic effect because its intensity should in principle not be dependent on T. The experimental data on the Rb2GeF6:Mn4+ fluoride and Cs2WO2F4:Mn4+ oxyfluoride phosphors are presented as a direct verification of this. A discussion is also given on the 2 E g → 4 A 2g transition properties in connection with the inelastic light scattering spectroscopy.

Na Replaces Rb towards High‐Performance Narrow‐Band Green Phosphors for Backlight Display Applications

AbstractThe improvement of high‐performance narrow‐band green phosphors in backlight display applications is still a major challenge. Based on the UCr4C4type of oxide phosphor, the high‐performance narrow‐band green phosphors Rb3M(Li3SiO4)4:Eu2+(M = Rb or Na) are studied in different luminous positions. Benefiting from the replacement of Rb by Na, the change of the local environment in the crystal structure of Rb3Na(Li3SiO4)4:Eu2+(R3NLSO:Eu2+) leads to the decrease of Stokes shift, which improves the quantum efficiency. Moreover, change in the local environment enhances the structural rigidity, which makes the thermal and chemical stability better. The R3NLSO:8%Eu2+phosphor presents a narrow‐band green emission centered at 527 nm, excellent thermal stability (102% @150 °C of the integrated emission intensity at room temperature), and high internal/external quantum efficiency (85.3%/40.4%). The white light‐emitting diode (wLED) using R3NLSO:8%Eu2+phosphor presents a superior luminous efficiency of 128.3 lm W‐1and a wide color gamut. All the results indicate that R3NLSO:8%Eu2+green phosphor has great application prospects in the field of liquid crystal display. This work also provides important guiding significance for the optimization of alkali metal element type of phosphors.

Mn-doped Ca14Al10(Zn,Mg)6O35: A deep-red oxide phosphor with high photoluminescence quantum yield and thermal stability

Mn-activated oxides have been widely regarded as a new class of red phosphors, while the weak absorption of blue light, low quantum yield (QY), and insufficient thermal quenching performance limit their applications. In this study, a series of deep-red emitting Ca14Al9.8Zn6−xMg0.1+xMn0.1O35 phosphors with outstanding luminescence performances are fabricated, and their optical and vibrational properties, as well as the thermal quenching mechanism, are investigated. The partial substitution of Mg for Zn not only greatly improves the absorption capability of blue light, but also suppresses the crystal defects, resulting in high QY (85.9% with excitation at 460 nm) and low thermal quenching effect (the emission intensity remains ~99.2% at 460 K and ~60.8% at 580 K relative to that at 300 K). This work demonstrates the great potential applications of Ca14Al9.8Zn6−xMg0.1+xMn0.1O35 phosphors in LED devices.

Evaluation of trapping parameters of europium doped tristrontium dialuminium oxide phosphor by different thermoluminescent analysis methods

In the present work, we have synthesized Europium (Eu) doped Tristrontium Dialuminium Oxide (Sr3Al2O6:Eu) phosphor by solid state reaction method in air atmosphere. The thermoluminescence (TL) properties of the synthesized phosphor are investigated and presented. Theoretical analysis of glow curves of Sr3Al2O6:Eu was done by computerized glow curve deconvolution (GCD) method, and the trapping parameters of the synthesized phosphor, such as activation energy, frequency factor, order of kinetics, etc. are discussed and explained. These trapping parameters are determined by different methods, such as Chen’s peak shape method, initial rise method, and Ilich method. The synthesized phosphor is found to be a good candidate for dosimetric applications.