Intense Green Emission Research Articles

Near-zero thermal quenching of upconversion green emission implemented with the polymorphic phase transition

Thermally stable upconversion luminescence is highly expected for applications in high-temperature environments. Herein, the mechanism of the phase transition inducing near-zero thermal quenching in upconversion green light is reported. The phosphor Ba3Gd0.78Yb0.2Er0·02Al2O7.5 is synthesized by the conventional high-temperature solid-state method and quenched in air during cooling. In-situ XRD and DSC curves demonstrate the polymorphic phase transition in the subsequent heating. The temperature-dependent upconversion luminescence exhibits stable green emission instead of thermal quenching when the material is excited by a 980 nm near-infrared laser. The more intense green emission resulting from the low symmetry of the low-temperature phase and its increase in the phase content with temperature are responsible for the thermal stability in the luminescence of the material. This research provides an approach to utilizing phase transformation to obtain stable emissions in upconversion phosphors.

Designing multicolor luminescence in Tb3+/Eu3+-codoped KGd2F7 nanoparticles through energy transfer engineering for warm white light-emitting diode

By a facile precipitation method at room temperature, series of Tb3+-doped and Tb3+/Eu3+-codoped KGd2F7 nanoparticles (NPs) were synthesized. Upon 377 nm excitation, Tb3+-doped KGd2F7 NPs possess intense green emissions and their strongest intensities are obtained when Tb3+ ion is 30 mol%, where the corresponding concentration quenching mechanism is electric dipole-quadrupole interaction. As for Tb3+/Eu3+-codoped KGd2F7 NPs, dazzling multi-color emissions are achieved, excited by 377 nm, triggered by the energy transfer (ET) from Tb3+ to Eu3+. Specially, the emitting color is changed from green to yellow and finally to red as Eu3+ content increases. Through systematical discussion based on the emission spectra and decay time, the ET mechanism is decided by dipole-dipole interaction. Moreover, Tb3+/Eu3+-codoped KGd2F7 NPs do not only have high thermal stability but also exhibit admirable quantum efficiency of 65.7% excited by 377 nm. Furthermore, through utilizing the resultant NPs as yellow-emitting components, a warm white light-emitting diode with high color rendering index (85.5) and low correlated color temperature (4323 K) is fabricated, which are insensitive to injection current. Our findings may provide promising luminescence materials with multicolor emissions to meet the requirement of phosphor-converted solid-state lighting.

A hierarchically porous MOF confined CsPbBr3 quantum dots: Fluorescence switching probe for detecting Cu (II) and melamine in food samples

The hypersensitivity of Perovskite quantum dots (PeQDs) towards external environmental conditions and the water quenching of their fluorescence have limited their practical analytical applications. In this work highly luminescent CsPbBr3 was confined into a hierarchically porous ZIF-8 metal organic framework (HZIF-8) through a simple two step in situ growth method. XRD, FTIR, SEM, TEM, and XPS investigations confirmed the successful synthesis of the CsPbBr3/HZIF-8 nanocomposite. CsPbBr3 PeQDs are uniformly distributed within the HZIF-8 MOF matrix and exhibited intense green emission at 510 nm with a FWHM value of 25 nm in ambient conditions. The nanocomposite showed enhanced stability against moisture and UV light. The intense PL emission of the nanocomposite was well maintained in an aqueous solution also, with no noticeable change in fluorescence characteristics for 15 days of storage in aqueous solution. The CsPbBr3/HZIF-8 composite was then utilized as an on–off-on luminescent probe for the detection of Cu2+ metal ions and melamine in real samples. Because of the porous nature of the MOF, the target analytes can be quickly located and this nanosensor is found to be very sensitive toward Cu2+ and melamine detection. A linear relationship from 3 to 500 nM and 30–1500 nM was found for melamine and Cu2+ under an optimal experimental condition, with a limit of detection value of around 4.66 nM and 2.64 nM for Cu2+ and melamine respectively.

Dazzling green luminescent and biocompatible Tb3+ -activated lanthanum tungstate nanophosphors for group-III evaluation of latent fingerprints and anticancer applications

Dazzling green emission exhibiting Tb3+ ions doped lanthanum tungstate (LWO) nanophosphors were synthesized by a facile hydrothermally assisted solid-state reaction method. The nanophosphors were determined to have an orthorhombic structure using XRD analysis. In the optimized Tb3+: LWO nanophosphor, FE-SEM revealed aggregated non-uniform nanorods. TEM, FTIR, and XPS studies were performed to examine the material properties. A predominant excitation band was recorded at 488 nm (7F6→5D4) for the Tb3+ doped LWO nanophosphors, along with a moderately intense excitation band at 378 nm (7F6→5G6). Ravishing green emission at 544 nm (5D4→7F5) was obtained from Tb3+ ions containing LWO nanophosphors under excitation at 378 nm and 488 nm. We improved the green emission intensity by increasing the Tb3+ ion concentration up to 14 mol%, which was reduced after 14 mol% due to concentration quenching. The energy-level diagram shows the green radiative transition pathway. The CIE coordinates and color purity were computed for Tb3+: LWO nanophosphors from their emission profiles, and the evaluated coordinates were centralized in the strong green region. A high color purity of 90.1% was obtained appreciably from the optimized Tb3+: LWO nanophosphor. The lifetime of the green emission transition was systematically evaluated based on decay dynamics. The visualization of fingerprints was examined using the optimized green phosphor with an in-depth analysis of the Group-III level details. The non-cytotoxicity of Tb3+ (14 mol%): LWO nanophosphor was confirmed in normal WI-38 lung fibroblast cells. Moreover, these phosphors exhibited strong cytotoxicity against human breast cancer cells of MCF-7. From these results, the synthesized Tb3+ (14 mol%): LWO non-cytotoxic nanophosphor material is considered the best green luminescent material for latent fingerprints in forensic investigation, photonic and anticancer applications.

Optical temperature sensing behavior of aluminum sheet fused with CaSrSiO4:Yb3+, Er3+ phosphor

In this work, Al–CaSrSiO4:Yb3+,Er3+ temperature sensing materials were prepared by the high-temperature solid-phase reaction method, and the upconversion photoluminescence characteristics and optical temperature sensing properties were measured and discussed. Two intense green emissions were observed under the excitation of 980 nm semiconductor laser. The temperature sensing performance of the thermally coupled energy levels was evaluated based on the fluorescence intensity ratio technique in the temperature range from 303 to 723 K, and the maximum sensor sensitivity of the synthesized sample reaches 0.0059 K−1 at 453 K. Furthermore, the relationships between the absolute sensitivity SA and temperature T as well as between SA and energy gap ΔE are analyzed in depth. And then, a strategy to quickly match the temperature measurement range to a suitable temperature sensing material was proposed, and the as-prepared Al–CaSrSiO4:Yb3+,Er3+ sample was determined to be suitable for measuring the high-temperature environment. These observations suggest that Al–CaSrSiO4:Yb3+,Er3+ samples have promising applications for non-contact optical temperature measurement at high temperature and high sensitivity.

Photoluminescence investigation of Tb3+-activated barium lutetium oxide microphosphor for latent fingerprint visualization

The feasibility of utilizing the microphosphor Ba3Lu4O9:Tb3+ in latent fingerprint visualization was explored in this work. The micromorphology and elemental composition of the phosphor particles were examined by X-ray photoelectron spectroscopy and transmission electron microscopy. The photoluminescence performance of Ba3Lu4O9:Tb3+ was characterized by the photoluminescence emission and excitation spectra together with the fluorescence decay curves. All the as-synthesized phosphors could be pumped by the ultraviolet, and the photoluminescence spectra consisted of line peaks from the typical 4 f→4 f transitions of Tb3+. The Ba3Lu3.98O9:0.02Tb3+ gave off intense green emission with CIE coordinate of (0.2904, 0.5430). The emission of this phosphor was well matched with the photopic luminosity curve. The photoluminescence intensity of the phosphor recorded at 425 K retained 77.8% of that at room temperature. Furthermore, in the fingerprint visualization experiment, based on this phosphor, the multilevel characteristics of LFP attached with the as-studied phosphor could be clearly identified. All the results signified that Ba3Lu4O9:Tb3+ microphosphor was a promising candidate for latent fingerprint visualization.

Selective Luminescent Chemosensing of Chloride Based on a Cyclometalated Platinum(II) Complex in Water: Crystal Structures, Spectroscopic Studies, Extraction, and Bioimaging

Selective anion sensing by luminescent chemosensors capable of operating in aqueous conditions is a central field of modern supramolecular chemistry that impacts analytical and biological chemistry. A cationic cyclometalated [Pt(N^C^N)NCCH3]OTf complex, 1 [N^C^N = 1,3-bis(1-(p-tolyl)-benzimidazol-2'-yl)benzene, OTf = triflate], was prepared, structurally described by single-crystal X-ray diffraction and studied in-depth as a luminescent chemosensor for anions in aqueous phase and solid state. A series of related neutral [Pt(N^C^N)X] complexes (X = Cl, 2; CN, 3 and I, 4) were formed readily upon treatment of 1 with the respective NaX salt in aqueous media and were described structurally by X-ray diffraction. Complex 1 is hydrostable with phosphorescent green emission originated by intraligand transitions, and [dyz(Pt) → π*(N^C^N)] charge transfer transitions, as evidenced by TD-DFT calculations and lifetime. Additions of halides, pseudohalides, oxyanions, and dicarboxylates to a neutral aqueous solution of 1 modified its green emission intensity with a pronounced affinity (K = 1.5 × 105 M-1) and turn-on signal toward Cl- within the micromolar concentration range. Pt complex 1 is two orders of magnitude more selective for Cl- than the other halides, CN- and basic oxyanions. Such Cl- affinity for a metal-based chemosensor in aqueous media is still rare. On the basis of X-ray crystallographic analysis and multiple spectroscopic tools (NMR, UV-vis, luminescence, MS, lifetimes) the origin of this selectivity hinges on the cooperative three-point recognition involving one coordination bond (Pt-Cl) and two convergent short C-H···Cl- contacts. This strong affinity and efficient optical response can be utilized in quantitative Cl- sensing in real samples and solid-liquid extractions. Additionally, chloro-Pt complex, 2 may be relevant to bioimaging as a marker for cell nuclei, as revealed by its emission within living cells and intracellular distribution by confocal microscopic studies. These results demonstrate the usefulness of the new water-stable luminescent Pt-N^C^N complexes as effective analytical tools in anion sensing and extraction agents.

Assessment of the Environmental Impact of Drug Products Using Life Cycle Assessment: A Case Study in a Pharmaceutical Company, Semarang

The pharmaceutical production process produces 55% greater emission intensity than the automotive industry. Along with increasing attention to the environmental impact of pharmaceutical drugs, pharmaceutical companies need to know the impact resulting from their production processes. This study analyzes the environmental impact of the anti-hangover drug production process using a Life Cycle Assessment. The analysis was carried out on 1 batch which produced 1,000,000 drugs. The scope of the gate to gate study from the initial process to the end of production. The research objective was to determine the potential impact resulting from the drug production process on the environment. The indicator measured is eco-cost, which is the cost of environmental impact calculated using the SimaPro software. This study found that the eco cost was IDR 3,931,237.65 with the largest environmental costs in the packaging process and the largest impact indicator on climate change. The biggest source of impact comes from the consumption of electrical energy. This study recommends the use of solar panels. For the energy conversion process, 80 KWp is needed with 288 solar panels and a land requirement of 0.564 Ha. This recommendation is estimated to reduce 22% percent of environmental costs.

Realizing multicolor tunable photoluminescence in La2MgTiO6: Tb3+, Eu3+ phosphors via energy transfer and application for white light-emitting diodes

The achievement of multiple emission color phosphors has a significant importance in screen display, lighting devices, and multicolor imaging, but it still faces formidable challenges. In this work, double perovskite La2MgTiO6: Tb3+, Eu3+ phosphors with tunable emissions are designed and successfully synthesized. The obtained phosphors can emit intense green (Tb3+), red (Eu3+), and yellow emissions (Tb3+/Eu3+) via varying the co-doping concentration of Tb3+ and Eu3+. The CIE coordinates exhibit an excellent linear behavior in La2MgTiO6: Tb3+, Eu3+, revealing the possibility of linear adjustment of multiple emission colors. Detailed material characterization demonstrates that the multicolor tunable emission originates from energy transfer between Tb3+ and Eu3+. The decay dynamics analysis suggests that the multipole interaction between Tb3+ and Eu3+ is quadrupole-quadrupole interaction. A white light-emitting diode device with color rendering index of 84.7, correlated color temperature of 4684 K, and CIE coordinate of (0.3472, 0.3083) is fabricated by combining La2MgTiO6: Tb3+, Eu3+ yellow phosphor and BaMgAl10O17: Eu2+ blue phosphor. Our results reveal that La2MgTiO6: Tb3+, Eu3+ phosphors are promising luminescent materials in white light-emitting diodes.

Highly Efficient and Stable Green Phosphorescent Light‐Emitting Diodes Based on Solution‐Processable Ir(III) Complexes with Electron‐Transporting Ancillary Ligands

AbstractTwo green heteroleptic Ir(III) complexes are reported, namely, bis[5‐(2‐ethylhexyl)‐8‐trifluoromethyl‐5H‐benzo[c][1,5]‐naphthyridin‐6‐one](2‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)phenolate)iridium (III) (Ir(CF3BNO)2‐pop) and bis[5‐(2‐ethylhexyl)‐5H‐benzo[c][1,5]naphthyridin‐6‐one](2‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)phenolate)iridium (III) (Ir(BNO)2‐pop) for solution‐processed phosphorescent organic light‐emitting diodes (PHOLEDs). Both the Ir(III) complexes exhibit high external quantum efficiency (EQE) and intense green emission upon using poly(3,4‐ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) as a hole injection layer (HIL); Ir(CF3BNO)2‐pop based PHOLEDs perform better with an EQE of 23% and a current efficiency of 82 cd A−1 than Ir(BNO)2‐pop based PHOLEDs. In addition, to improve device operational lifetime, a crosslinkable HIL material, 9,9'‐(cyclohexane‐1,1‐diylbis(4,1‐phenylene))bis(N‐phenyl‐N‐(4‐(((4‐vinylbenzyl)oxy)methyl)phenyl)‐9H‐carbazol‐3‐amine) (CPCzDPAX‐1) is designed and synthesized. Device operational lifetimes of Ir(CF3BNO)2‐pop and Ir(BNO)2‐pop PHOLEDs incorporating the CPCzDPAX‐1 HIL show 14‐fold and 6‐fold improvement, compared to the corresponding devices incorporating the PEDOT:PSS HIL. To the best of the authors’ knowledge, this is the best device lifetime performance by using the combination of new Ir(III) complexes and HIL materials for solution‐processed green PHOLEDs.

The impact of pure and mixed self-activated YXO4 phosphor materials (X=V, Nb and Ta) on downshifting and quantum cutting emission behaviours of Ln3+ doped (Ln3+=Ho3+ and Yb3+) ions

In this work, the downconversion (DC) behaviour of Ho3+ ions doped in pure YVO4, YNbO4, YTaO4 hosts and their intermixed (i.e. Ta/V, Ta/Nb and Nb/V) compositions have been investigated and compared. The samples were synthesized by solid-state reaction technique at 1473 K. The UV–Vis absorption and photoluminescence behaviour of 1 mol % Ho3+ doped YVO4, YNbO4 and YTaO4 as well as their intermixed compositions have been studied. The DS green emission of Ho3+ ion in vanadate host (λexc = 326 nm) is 5 times stronger than in niobate host (λexc = 262 nm) due to efficient energy transfer between [VO4]3- and Ho3+ ion. The downshifting (DS) emissions are also investigated on direct excitation of Ho3+ ion in YVO4, YNbO4 and YTaO4 hosts on excitation with 450/456 nm (5I8→5G6 transition of Ho3+ ion) wavelength. It is found that the overall DS emission intensity is dominant in YNbO4:Ho3+ phosphor due to low phonon frequency and larger particle size of YNbO4. The Ho3+ doped in mixed hosts viz. YTa1-xVxO4, YTa1-yNbyO4, YNb1-zVzO4 (where x, y and z = 0, 0.25, 0.50, 0.75 and 1.0) phosphors also emit intense green DS emission along with their violet-blue band emission on ultraviolet (UV) excitation. The mixing of Ta/V and Ta/Nb enhances the blue emission of host matrix on UV excitation. The green emission is found to increase with ‘V’ and ‘Nb’ concentrations in YTa1-xVxO4:0.01Ho3+, YTa1-yNbyO4:0.01Ho3+, respectively. Further, we also investigated quantum cutting (QC) in YNb1-zVzO4:5 mol% Yb3+ (where z = 0, 0.25, 0.50, 0.75, 1.0) phosphors on UV excitation (λexc = 262 and 326 nm). The intensity of QC NIR emission is found to increase with the incorporation of ‘V’ in YNb1-zVzO4 phosphors. The strongest QC emission is observed in pure YVO4 host as compared to pure YNbO4 as well as other mixed matrices. The QC efficiency of NIR emission for YVO4:5 Yb has been calculated and found to 129%. Therefore, the prepared phosphor material is highly applicable to increase the efficiency of Si- solar cell by QC NIR emission.

Effect of glass-ceramics network intermediate Al2O3 content on up-conversion luminescence in Er3+/Yb3+ co-doped NaYF4 oxy-fluoride glass-ceramics

Effect of alumina as a glass network intermediate on the up-conversion luminescence (UCL) in NaYF4:Er3+/Yb3+ co-doped oxy-fluoride glass-ceramics (GCs) was investigated. Combinations of smaller NaYF4 nanocrystals (10 and 13 nm) and lower Al2O3 contents (5% and 10%), as well as larger NaYF4 nanocrystals (26 and 40 nm) and higher lower Al2O3 contents (15% and 20%) were prepared after heat-treatment, respectively. The glass network of intermediate partial replacement of SiO2 with Al2O3 was investigated, and the consequence on the response to the up-conversion of the lanthanide ions was also studied. The UCL properties of Er3+ ions were changed in accordance with the addition of Al2O3, the red UCL intensity decreased with an increased Al2O3 concentration, while the green emission intensity showed opposite tendency. Our results showed that adding Al2O3 to 20 mol% is an effective strategy to simultaneous control of the magnitude and luminescence properties of lanthanide ion doped GCs.

Down-shifting photoluminescent properties of Tb3+ doped phosphate glasses for intense green-emitting devices applications

Tb3+ doped BZLP glasses were prepared via a melt-quenching route and investigated thoroughly using spectroscopic techniques such as XRD, UV-VIS absorption and photoluminescence (PL) to explore their utility in visible photonic device applications. The information pertaining to glass transition temperature, melting temperature, and thermal stability were understood by using recording the differential scanning calorimetry (DSC) spectrum for an undoped BZLP glass. The total weight loss during the glass composition melting process was analyzed using Thermogravimetric curves. The UV spectral information recorded for the titled glasses reveals the optical bandgap falling in the range from 4.57 to 4.19 eV. The prepared Tb3+ doped BZLP glasses exhibit intense green emission along with relatively less intense blue, yellow, and red peaks under 373 nm excitation. In the resultant PL spectra, the emission intensity increases with the activator concentration of Tb3+ ions from 0.5 to 5.0 mol%. The estimated CIE chromaticity coordinates falling in the green region reveal the aptness of the titled glasses as a green constituent in visible photonic devices. The PL decay curves show the bi-exponential behavior with an average decay time of 2–3 ms. The temperature-dependent PL profile shows fewer changes in spectra and has a relatively high activation energy value, confirming the high thermal stability. Various results obtained for Tb3+ doped BZLP glasses finally reveal their usage as a green emitter needed to fabricate w-LEDs and other green-emitting photonic device applications.

Temperature-Dependent Reversible Optical Properties of Mn-Based Organic–Inorganic Hybrid (C8H20N)2MnCl4 Metal Halides

Organic-inorganic metal halides (OIMHs) have abundant optical properties and potential applications, such as light-emitting diodes, displays, solar cells, and photodetectors. Herein, we report zero-dimensional Mn-based OIMH (C8H20N)2MnCl4 single crystals synthesized by a simple slow evaporation method, which exhibit intense green emission at 520 nm originating from 4T1-6A1 transition of Mn2+ ions. Large organic cations in the crystal structure result in the isolated [MnCl4]2- tetrahedrons, and the closest Mn-Mn distance reaches 9.07 Å, which effectively inhibits the migration of excitation energy between adjacent Mn2+ emission centers, thus achieving a high quantum yield (∼87%) and a long photoluminescence (PL) lifetime (3.42 ms). The different optical and structural properties at low and high temperatures are revealed by temperature-dependent PL and X-ray diffraction spectra. The PL spectra and lifetimes under the heating and cooling processes indicate that the optical property transitions are reversible at 220/240 K. Our work provides a promising strategy for building multifunctional optoelectronic materials and insights into the understanding convertible photophysical properties from isomers of metal halides.

Utilization of BaAl1.4Si0.6O3.4N0.6:Eu2+ Green-emitting Phosphor to Improve Luminous Intensity and Color Adequacy of White Light-emitting Diodes

BaAl1.4Si0.6O3.4N0.6:Eu2+ exhibiting broad excitation and emission bands with intense green emission centred at 510 nm is applied to produce high-performance white-light-emitting diodes (WLEDs). The preparation of the green phosphor utilizes NaNO3

Preparation and Luminescence Properties of Rare Earth Doped Upconversion Phosphors

Upconversion luminescence GdF₃: Er³⁺, Yb³⁺ phosphors were prepared under different reaction conditions by a hydrothermal method. X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and upconversion (UC) emission spectra were used to characterize the samples. The results of XRD indicate that the formation of cubic phase GdF₃ depends on the hydrothermal reaction time and reaction temperature. The results of SEM show that morphology of the sample changes with changing different reaction temperatures. The results of the upconversion emission spectra show: under 980nm infrared excitation, that green emission is from ²H_11/2→⁴I_15/2 and ⁴S_3/2→⁴I_15/2 transitions of Er³⁺ ions and red emission comes from ⁴F_9/2→⁴I_15/2 transitions of Er³⁺ ions. A: Red emission intensity is significantly stronger than the green emission intensity, B: Green emission intensity is significantly stronger than the red emission intensity for two samples.

Multifunctional optical thermometry using dual-mode green emission of CaZrO3:Er/Yb/Mo perovskite phosphors.

The weak emission intensity of rare-earth element-doped dual-mode materials leads to low-sensor sensitivity, which is a challenge in optical sensor applications. The present work achieved high-sensor sensitivity and high green color purity based on the intense green dual-mode emission of Er/Yb/Mo-doped CaZrO3 perovskite phosphors. Their structure, morphology, luminescent properties, and optical temperature sensing properties have been investigated in detail. Phosphor shows a uniform cubic morphology with an average size of approximately 1 μm. Rietveld refinement confirms the formation of single-phase orthorhombic CaZrO3. Under the excitation of 975 and 379 nm, the phosphor emits pure green up and down-conversion (UC and DC) emission at 525/546 nm corresponding to 2H11/2/4S3/2-4I15/2 transitions of Er3+ ions, respectively. Intense green UC emissions were achieved because of energy transfer (ET) from the high-energy excited state of Yb3+-MoO42- dimer to the 4F7/2 level of Er3+ ion. Furthermore, the decay kinetics of all obtained phosphors confirmed ET efficiency from Yb3+-MoO42- dimer to Er3+ ions, leading to strong green DC emission. Moreover, the DC of the obtained phosphor shows that a sensor sensitivity value of 0.697% K-1 at 303 K is higher than the UC (0.667% K-1 at 313 K) because the thermal effect generated by the DC excitation source light is ignored compared with UC luminescence. CaZrO3:Er-Yb-Mo phosphor shows intense green dual-mode emission with high green color purity, 96.50% of DC and 98% of UC emissions, and high sensitivity, making it suitable for optoelectronic devices and thermal sensor applications.

Stable borosilicate glass doped with CsPbBr3 quantum dots for efficient photodetectors

Cesium halide lead perovskite quantum dots (QDs) have attracted great attention in the field of optoelectronics due to their excellent photoelectric characteristics. Unfortunately, the susceptibility to anion exchange, instability in air and poor water resistance of perovskite QDs hinder their practical applications. In this study, borosilicate glass doped with CsPbBr3 QDs were prepared by traditional melt quenching and heat treatment procedures, which dramatically enhances the stability of perovskite QDs. The microstructures and luminescence properties of glass ceramics were carefully investigated. Intense green emissions were observed in the QDs doped glass under the excitation of ultraviolet light. More importantly, the photodetectors based on the CsPbBr3 QDs doped glass possess a high on/off photocurrent ratio of 104. The dynamic linear response range is large and the response speed is fast under low bias working condition. The results suggest that CsPbBr3 QDs doped glasses with high emission yield could find potential applications in highly efficiency photodetectors.

Efficient down-shifting and up-conversion emission dual-mode in RE3+-doped NaTbF4-based nano-glass ceramics

Intense green and red emissions, visible to the naked eye, coming from Tb3+ to Eu3+ ions, respectively, were observed by down-shifting (from UV-blue excitation) and by cooperative up-conversion (from 980 nm excitation) mechanisms.

Luminescence properties of Pr3+ doped high density germanate scintillating glasses for fast-event X-ray detection

Pr 3+ doped high density germanate glasses were prepared by the melt-quenching method. The physical and luminescent properties were investigated. The glass containing BaF 2 represented maximum phonon energy of 810 cm −1 , and the glass density was greater than 6 g/cm 3 . The glass exhibited good radiation resistance under 2 h of X-ray irradiation. Intense blue, green emissions and weak red emissions were observed when the glass was excited by X-ray, and the blue fluorescence lifetimes were in the range of 9.15–12.59 μs The results show that Pr 3+ doped germanate glass could be a potential scintillating material in the field of X-ray detection for fast events.