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A yellowish‐green emitting phosphor Ba3YAl2O7.5:Eu2+ was synthesized by a solid‐state method. The crystal structure, luminescence, concentration quenching, fluorescence decay, and thermal quenching properties were systematically investigated. Under blue light (440 nm) excitation, Ba3YAl2O7.5:Eu2+ phosphors exhibit a yellowish‐green emission peaking at 550 nm with a full width at half maximum ∼ 69 nm, and The Commission Internationale de l'Eclairage (CIE) coordinates of Ba3YAl2O7.5:Eu2+ are (0.4064, 0.5811). Structural analysis and Van Uitert equation along with fluorescence lifetime analysis reveal that Eu2+ ions occupy 6‐coordinated Y and 9‐coordinated Ba sites in Ba3YAl2O7.5, and therefore generate two emission sub‐bands at 582 and 548 nm. In addition, Ba3YAl2O7.5:Eu2+ phosphor remaining 43% photoluminescence emission intensity at 125°C with an activation energy of 0.372 eV. Utilizing the title phosphor (Ba3YAl2O7.5:3%Eu2+), commercial red (Ca,Sr)AlSiN3:Eu2+ (CSAlSi:Eu2+) phosphor, and InGaN‐based blue light emitting diode (LED) chip, a proof‐of‐concept warm white LEDs (WLEDs) with a color rendering index of 80.1, CIE chromaticity coordinates of (0.411, 0.381), luminous efficacy of ∼ 22.13 lm/W, and correlated color temperature of ∼ 3288 K is achieved. Thus, Eu2+ activated Ba3YAl2O7.5 phosphors have the potential application in WLEDs pumped by a blue LED chip for solid‐state lighting application. [ABSTRACT FROM AUTHOR]

A yellowish‐green emitting phosphor Ba3YAl2O7.5:Eu2+ was synthesized by a solid‐state method. The crystal structure, luminescence, concentration quenching, fluorescence decay, and thermal quenching properties were systematically investigated. Under blue light (440 nm) excitation, Ba3YAl2O7.5:Eu2+ phosphors exhibit a yellowish‐green emission peaking at 550 nm with a full width at half maximum ∼ 69 nm, and The Commission Internationale de l'Eclairage (CIE) coordinates of Ba3YAl2O7.5:Eu2+ are (0.4064, 0.5811). Structural analysis and Van Uitert equation along with fluorescence lifetime analysis reveal that Eu2+ ions occupy 6‐coordinated Y and 9‐coordinated Ba sites in Ba3YAl2O7.5, and therefore generate two emission sub‐bands at 582 and 548 nm. In addition, Ba3YAl2O7.5:Eu2+ phosphor remaining 43% photoluminescence emission intensity at 125°C with an activation energy of 0.372 eV. Utilizing the title phosphor (Ba3YAl2O7.5:3%Eu2+), commercial red (Ca,Sr)AlSiN3:Eu2+ (CSAlSi:Eu2+) phosphor, and InGaN‐based blue light emitting diode (LED) chip, a proof‐of‐concept warm white LEDs (WLEDs) with a color rendering index of 80.1, CIE chromaticity coordinates of (0.411, 0.381), luminous efficacy of ∼ 22.13 lm/W, and correlated color temperature of ∼ 3288 K is achieved. Thus, Eu2+ activated Ba3YAl2O7.5 phosphors have the potential application in WLEDs pumped by a blue LED chip for solid‐state lighting application. [ABSTRACT FROM AUTHOR]

Achieving efficient blue electroluminescence (EL) is a crucial challenge for the commercial application of perovskite light-emitting diodes (LEDs), especially for pure blue light with wavelengths of 465~ 475 nm. The main factors contributing to the low efficiency of blue light perovskite LEDs are the high defect density and difficulties in carrier injection induced by the mixed halogen and dimensionality reduction strategies. Herein, we propose an approach for achieving high-performance pure-blue perovskite LEDs by incorporating a fluorine-containing phosphine oxide derivative (PFPO). This incorporation significantly suppresses the non-radiative recombination and fine-tunes the low-dimensional phase distribution of quasi-2D perovskites. The device results reveal that the maximum external quantum efficiency (EQE) of PFPO-treated perovskite LEDs has increased from 1. 83% to 3. 62%. The emission peak is located at 466 nm, corresponding to CIE of (0. 123, 0. 079), which is close to the International Telecommunication Union (ITU) Rec. 2020 blue standard (0. 131, 0. 046). [ABSTRACT FROM AUTHOR]

We report on metalorganic vapor phase epitaxy of highly conductive germanium-doped GaN layers and their application for blue tunnel-junction light emitting diodes (TJ-LEDs). Using Ge as donor, carrier densities of up to 2 × 1020 cm−3 and low bulk resistivities down to 3 × 10−4 Ωcm are achieved. Under optimum growth conditions, no degradation of the crystalline quality is observed and layers exhibit high transparency making GaN:Ge very attractive as current spreading layer in light emitting devices. We have realized GaN-based TJ-LEDs by capping conventional InGaN LED structures with highly doped GaN:Ge. Such TJ-LEDs withstand operation currents up to 20 kA/cm2 in continuous and up to 60 kA/cm2 in pulsed operation conditions. Moreover, TJ-LEDs exhibit homogeneous electroluminescence and light output through the top surface that is increased by more than 60% as compared to conventional LEDs with transparent indium tin oxide contacts. The impact of the doping profile, carrier gas conditions, and acceptor activation by annealing for low-resistive TJ characteristics is discussed. Light output and current voltage characteristics of blue-light emitting devices with GaN-TJ are presented at low and high-current densities. [ABSTRACT FROM AUTHOR]

Synthesis of strongly quantum confined and emissive CsPbBr3 perovskite nanocrystals with sizes <4 nm has proven challenging owing to fast nucleation and rapid growth. In this work, ultra-small blue-emitting (∼461 nm) CsPbBr3 nanocrystals with an average particle size of 3.2 nm are synthesized via a high-temperature (170 °C) colloidal approach by controlling the supersaturation reaction conditions. Our approach yielded stable nanocrystals with uniform size, shape, and excellent color purity, making them promising for blue light emitting diode (LED) applications. [ABSTRACT FROM AUTHOR]

The application of non‐Cd quantum dots in future display technologies is promising due to their environmental friendliness. However, their low efficiency and broad emission linewidth limit their practical usage. Here, we report the fabrication of ZnSeTe quantum dots based blue light emitting diode (QLED) with different amounts of Te doping and top‐emitting structure. By regulating the thickness of the electron transport layer, we achieve electrical and optical balance control in QLED. Ultimately, we obtain a blue QLED with a emission wavelength of 461 nm, a current efficiency of 5.8 cd/A and a pure blue chromaticity coordinates of (0.13, 0.08). [ABSTRACT FROM AUTHOR]

A hybrid cadmium sulfide nanoparticles (CdSNPs) electroluminescence (EL) device was fabricated by Phase – Segregated Method and characterized. It was fabricated as layers of (ITO/poly-TPD:CdS ) and (ITO/poly-TPD:CdS /Alq3). PolyTPD is an excellent Hole Transport Layer (HTL), CdSNPs is an emitting layer and Alq3 as electron transport layer (ETL). The EL of Organic-Inorganic Light Emitting Diode (OILED) was studied at room temperature at 26V. This was achieved according to band-to-band transition in CdSNPs. From the I-V curve behavior, the addition of Alq3 layer decreased the transfer of electrons by about 250 times. The IV behavior for (poly-TPD/CdS) is exponential with a maximum current of 4500 µA. While, the current is constant for (poly-TPD:CdS /Alq3) and the maximum current was 16.5 µA. Semiconductor nanoparticles like CdS are attractive for fabricating hybrid LEDs with spectrally pure color, low operating voltage values, and shortwavelength electro-luminescence, needed for the RGB devices. The correlated color temperature (CCT) was equal to (1700 oK) for the emitted blue light. [ABSTRACT FROM AUTHOR]

Agarose gel electrophoresis is a routinely employed experimental technique for visualizing nucleic acids, typically combined with ethidium bromide or some other molecular dye staining and a UV transilluminator. However, the utilization of a UV transilluminator is restricted due to high cost and safety considerations. In this study, an inexpensive and simple in-house blue Light Emitting Diode (LED) transilluminator was developed using a highbrightness blue LED, carbon resistor, and smartphone charging cable. Its sensitivity for DNA detection was compared with conventional methods. A detection limit of 4 ng/band was confirmed by observing a 100 bp DNA fragment, which is comparable to ethidium bromide staining and UV transilluminator. Additionally, the in-house blue LED transilluminator can be attached to existing electrophoresis chambers, allowing real-time observation of electrophoresis and offering a superior alternative to conventional methods. In conclusion, the developed in-house blue LED transilluminator demonstrates high sensitivity in detecting DNA fragments and holds potential for advancing low-cost research facilities. [ABSTRACT FROM AUTHOR]

The management of skin burns is still challenging. Among the therapeutic methods used, there are topical treatments with pharmacological and herbal agents, low-intensity therapeutic ultrasound, use of biomaterials, reconstructive techniques and photobiomodulation therapy. The aim of this study was to evaluate the effects of photobiomodulation with blue Light Emitting Diode (LED) on burn healing. Fifty Wistar rats were divided into control (CTRL) (n = 25) and blue LED (LED) (n = 25), with subgroups (n = 5) for each time of euthanasia (7, 14, 21, 28 and 32 days). Treated animals were daily irradiated (470 nm, 1W, 0.44 W/cm2, 50 J/cm2). Clinical evaluations were performed and the Wound Retraction Index (WRI) was determined. Histological sections were submitted to hematoxylin–eosin, toluidine blue and the immunohistochemical technique, with anti-α-SMA and anti-TGF-β1 antibodies. All data were directly collected by previously calibrated evaluators in a blind manner. The values were included in a statistical program. For all statistical tests used, 5% significance level (p < 0.05) was considered. No statistically significant differences in WRI between groups were observed (p > 0.05). Re-epithelialization was higher using LED at 7 and 14 days (p < 0.05) and greater amount of inflammatory cells was observed at 7 days (p = 0.01). With LED at 21 and 32 days, greater number of mast cells were observed (p < 0.05), as well as smaller number of myofibroblasts at 14, 21, 28 and 32 days (p < 0.05) and lower percentage of TGF-β1 positive cells in the conjunctiva at 7, 14 and 21 days (p < 0.05). Negative correlations were observed in LED between the percentage of TGF-β1 in the epithelium and the mean number of inflammatory cells and number of myofibroblasts (p < 0.05). The results suggest that, depending on the period, blue LED can modulate the healing processes of third-degree skin burns, such as re-epithelialization, inflammatory response, mast cell concentration, myofibroblast differentiation and TGF-β1 immunoexpression. Despite these effects, this therapy does not seem to have significant influence on the retraction of these wounds. Future studies, using different protocols, should be carried out to expand the knowledge about the photobiomodulatory mechanisms of this type of light in the healing process. [ABSTRACT FROM AUTHOR]

A synthetic method to prepare 1-alkyl-substituted-pyrazolidin-3-ones efficiently that relies on the 4CzPN-mediated alkylation of azomethine imines by 4-alkyl-substituted-1,4-dihydropyridines (DHPs) under blue light emitting diode (LED) light (λmax = 456 nm) is reported. An approach that exploits the ability of blue LED light to initiate the acylation of the imine substrate by 4-acyl-substituted-DHPs to give 1-acyl-substituted-pyrazolidin-3-ones is also presented. Achieved under mild reaction conditions at room temperature, the synthetic protocol was shown to tolerate a broad range of functional groups to afford the corresponding 1-substituted-pyrazolidin-3-ones in yields up to 99%. [ABSTRACT FROM AUTHOR]

A few unit cells of thick colloidal CsPbBr3 nanoplatelets (NPLs) exhibit strong quantum confinement. However, due to the increased surface‐to‐volume ratio, they show poor photoluminescence quantum yield (PLQY) resulting from surface traps. Here, a unique, quantum‐confined core/crown perovskite is reported for the first time, where the CsPbBr3 NPL surface is passivated by laterally grown thin FAPbBr3 crown layers. Unlike regular core/shells, the FAPbBr3 is coated around the core NPLs resulting in blue emission. Careful control of the growth kinetics while monitoring growth using in situ PL led to the formation of core/crown perovskites with nearly two times improvement in thin film PLQYs. HR‐TEM analyses show that the interplanar distances of the core match with CsPbBr3 and the crown match with FAPbBr3. The XRD and TEM analyses revealed that their thickness remains the same even if Cs+ to FA+ ratios are varied, indicating lateral growth of FAPbBr3 around the CsPbBr3 core. Further, FA+ ions in the crown lattice are confirmed by FTIR and 1HNMR. Finally, considering their high PLQYs and narrow linewidths, the core/crown NPLs are employed as blue emitters in light‐emitting diodes, and a maximum external quantum efficiency of 0.4% at 2.71 eV (457 nm) with a luminance of 513 cd m−2 is achieved. [ABSTRACT FROM AUTHOR]

A visible‐light‐driven approach towards phenanthridin‐6(5H)‐one and carbazole rings synthesis under transition‐metal‐free conditions is here reported. Phenanthridinones and carbazoles are synthesized through an intramolecular arylation of the corresponding N‐(2‐halobenzyl)‐N‐methylanilines or N‐substituted‐N‐phenyl anilines using KOtBu as base in dimethyl sulfoxide (DMSO) at room temperature (rt), employing blue light emitting diodes (LEDs) as the light source. The reaction proceeds through photo‐ and base‐promoted homolytic aromatic substitution via photoinduced electron transfer mechanism and it exhibits good tolerance to different functional groups, resulting in good to very good yields (up to 86 %). [ABSTRACT FROM AUTHOR]

Chlorophyll fluorescence measured at the leaf scale through pulse amplitude modulation (PAM) has provided valuable insight into photosynthesis. At the canopy- and satellite-scale, solar-induced fluorescence (SIF) provides a method to estimate the photosynthetic activity of plants across spatiotemporal scales. However, retrieving SIF signal remotely requires instruments with high spectral resolution, making it difficult and often expensive to measure canopy-level steady-state chlorophyll fluorescence under natural sunlight. Considering this, we built a novel low-cost photodiode system that retrieves far-red chlorophyll fluorescence emission induced by a blue light emitting diode (LED) light source, for 2 h at night, above the canopy. Our objective was to determine if an active remote sensing-based night-time photodiode method could track changes in canopy-scale LED-induced chlorophyll fluorescence (LEDIF) during an imposed drought on a broadleaf evergreen shrub, Polygala myrtifolia. Far-red LEDIF (720–740 nm) was retrieved using low-cost photodiodes (LEDIFphotodiode) and validated against measurements from a hyperspectral spectroradiometer (LEDIFhyperspectral). To link the LEDIF signal with physiological drought response, we tracked stomatal conductance (g sw) using a porometer, two leaf-level vegetation indices—photochemical reflectance index and normalized difference vegetation index—to represent xanthophyll and chlorophyll pigment dynamics, respectively, and a PAM fluorimeter to measure photochemical and non-photochemical dynamics. Our results demonstrate a similar performance between the photodiode and hyperspectral retrievals of LEDIF (R 2 = 0.77). Furthermore, LEDIFphotodiode closely tracked drought responses associated with a decrease in photochemical quenching (R 2 = 0.69), F v/ F m (R 2 = 0.59) and leaf-level photochemical reflectance index (R 2 = 0.59). Therefore, the low-cost LEDIFphotodiode approach has the potential to be a meaningful indicator of photosynthetic activity at spatial scales greater than an individual leaf and over time. [ABSTRACT FROM AUTHOR]

Off-axis electron holography has been used to measure the width of the depletion region in a series of tunnel junction GaN light emitting diodes that have been prepared using different growth processes for blue emission. The total measured potentials are combinations of the mean inner potential, dopant potential, and piezoelectric contributions. The dopant potential has been unmixed from the mean inner potential such that the width of the tunnel junctions in the different diodes can be measured. The experimental results are then compared to secondary ion mass spectrometry, simulations, and opto-electronic testing. We find that the measured tunnel junction widths are consistent with simulations as well as the current density and voltage characteristics. As such, off-axis electron holography has been demonstrated as a unique technique that can be used to reproducibly measure the electrostatic potentials in tunnel junctions with nm-scale resolution in real III–V device specimens. [ABSTRACT FROM AUTHOR]

Metal halide perovskite nanocrystals (NCs) have emerged as highly promising light emitting materials for various applications, ranging from perovskite light‐emitting diodes (PeLEDs) to lasers and radiation detectors. While remarkable progress has been achieved in highly efficient and stable green, red, and infrared perovskite NCs, obtaining efficient and stable blue‐emitting perovskite NCs remains a great challenge. Here, a facile synthetic approach for the preparation of blue emitting CsPbBr3 nanoplatelets (NPLs) with treatment by an organic sulfate is reported, 2,2‐(ethylenedioxy) bis(ethylammonium) sulfate (EDBESO4), which exhibit remarkably enhanced photoluminescence quantum efficiency (PLQE) and stability as compared to pristine CsPbBr3 NPLs coated with oleylamines. The PLQE is improved from ≈28% for pristine CsPbBr3 NPLs to 85% for EDBESO4 treated CsPbBr3 NPLs. Detailed structural characterizations reveal that EDBESO4 treatment leads to surface passivation of CsPbBr3 NPLs by both EDBE2+ and SO42– ions, which helps to prevent the coalescence of NPLs and suppress the degradation of NPLs. A simple proof‐of‐concept device with emission peaked at 462 nm exhibits an external quantum efficiency of 1.77% with a luminance of 691 cd m−2 and a half‐lifetime of 20 min, which represents one of the brightest pure blue PeLEDs based on NPLs reported to date. [ABSTRACT FROM AUTHOR]

Multi‐resonant thermally activated delayed fluorescent (MR‐TADF) materials are blooming for high‐resolution organic light‐emitting diodes (OLEDs). However, boron/nitrogen (B/N)‐integrated MR‐TADF emitters suffer severe efficiency roll‐off from their strong inter‐molecular π–π interactions. Herein, versatile narrowband pure blue emitters (mono‐mx‐CzDABNA and tri‐mx‐CzDABNA) are demonstrated featuring a ring‐fused extended π‐skeleton: a classic steric hindrance and rigidity accessed by integrating with meta‐xylene (mx) rotors. tri‐mx‐CzDABNA shows a narrowband (FWHM, 26 nm) pure blue emission (λmax, 462 nm) with substantial hypsochromic shift (12 nm) while maintaining MR‐TADF characteristics. The key solid‐state analyses conclude that they conceivably suppress the non‐radiative energy loss, thus improving the photoluminescence quantum yield (PLQY > 90%) and rate of reverse intersystem crossing (RISC) (kRISC ≈2.85 × 105 s−1). The integration of tri meta‐xylene significantly leads to an enhanced horizontal dipole ratio (HDR) from 65% to 85%. Hyperfluorescent‐OLEDs are fabricated using designed MR‐TADF as terminal emitter, achieving a narrowband (FWHM, 34 nm) pure blue electroluminescence (λmax, 472 nm) and maximum external quantum efficiency (EQEmax) of 26.97% with magnificently suppressed efficiency roll‐off (7.8%) at 1000 cd m−2. So, it is believed that regulation of internal efficiencies and high color purity can amplify the route to achieving a narrowband pure blue emission through new synthetic MR‐TADF approaches. [ABSTRACT FROM AUTHOR]

Non-life-threatening adverse reactions occurred in 9/20 dogs (45%) including hypersalivation, lip smacking and restlessness attributed to nausea (five dogs), injection site pruritus (three dogs), and self-limiting diarrhoea and lethargy (one dog). In this report, two ovariohysterectomised dogs (six-year-old Shetland sheepdog and 14-year-old shih tzu dog) from separate households developed extensive, noninflammatory alopecia on the trunk, tail and proximal limbs within 10 months after starting oral estriol supplementation for urinary incontinence at labelled doses. As the treatment and bandaging protocol as well as the allergy treatment otherwise were completely identical, and the surgery happened at the same time of year, this major difference (also to expected standard laser wound recovery times) appeared impressive as the dog served as its own control group. E. J. Rosser College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA The objective was to examine the dermatohistopathological and immunohistochemical features of skin biopsies from 10 food-allergic dogs. Eight lesional skin samples from eight PF dogs and five healthy site-matched samples from five healthy dogs were evaluated for 20 immune markers using quantitative real-time PCR. [Extracted from the article]

A synthetic method to prepare 1,2‐diamines efficiently that relies on the 4CzPN‐catalysed α‐aminoalkylation of azomethine imines by secondary and tertiary α‐silylamines under blue light emitting diode (LED) light (456 nm) is described. Achieved under metal‐ and additive‐free reaction conditions at room temperature, the synthetic protocol was shown to afford product yields up to 99% and applicable to the late‐stage functionalisation of three drug molecules and the gramme‐scale preparation of one example. [ABSTRACT FROM AUTHOR]

Keywords: benzyne; N -alkylpyridinium salts; dicarbofunctionalization; visible light; C-H arylation; de Mayo-type reaction EN benzyne N -alkylpyridinium salts dicarbofunctionalization visible light C-H arylation de Mayo-type reaction 2159 2165 7 07/03/23 20230718 NES 230718 It is widely known that arynes are a useful and transient intermediate in synthetic organic chemistry. After cooling to room temperature, the reaction mixture was concentrated in vacuo and the residue was purified by silica gel flash column chromatography (hexane/EtOAc = 2:1) to afford B 3q b as a yellow solid; mp 157-160 °C. After cooling to room temperature, the reaction mixture was concentrated in vacuo and the residue was purified by silica gel flash column chromatography (hexane/EtOAc = 5:1) to afford B 3r b as a yellow solid; mp 133-135 °C. After cooling to room temperature, the reaction mixture was concentrated in vacuo and the residue was purified by silica gel flash column chromatography (hexane/EtOAc = 2:1) to afford B 3p b as sa yellow solid; mp 130-132 °C. [Extracted from the article]

Regular resonance modes in GaN-based polygonal microdisks are investigated by simulations and photoluminescence measurements. Based on a standard GaN-based blue light emitting diode wafer on a Si substrate, hexagonal and octagonal microdisks with similar dimensions are fabricated. Whispering gallery-like modes and Fabry–Pérot modes in the polygonal microcavities are pictured by theoretical calculations. All resonant modes in the polygonal microdisks are confined along regular and isolated orbits. The resonant emission from the hexagonal and octagonal microdisks has been achieved at room temperature, which presents regular and ordered resonant emission peaks. The regularly varied mode spacing of the polygonal microdisks provides potential application in multiple-channel optic communication. The distinctive geometric structural features and mode characteristics make the polygonal microdisks greatly superior in terms of mode control and mode selection. [ABSTRACT FROM AUTHOR]

By studying low radiative efficiency blue III-nitride light emitting diodes (LEDs), we find that the ABC model of recombination commonly used for understanding efficiency behavior in LEDs is insufficient and that additional effects should be taken into account. We propose a modification to the standard recombination model by incorporating a bimolecular nonradiative term. The modified model is shown to be in much better agreement with the radiative efficiency data and to be more consistent than the conventional model with very short carrier lifetimes measured by time-resolved photoluminescence in similar, low radiative efficiency material. We present experimental evidence that a hot carrier-generating process is occurring within these devices, in the form of measurements of forward photocurrent under forward bias. The forward photocurrent, due to hot carrier generation in the active region, is present despite the lack of any "efficiency droop"—the usual signature of band-to-band Auger recombination in high-quality III-nitride LEDs. Hot carrier generation in the absence of band-to-band Auger recombination implies that some other source of hot carriers exists within these low radiative efficiency devices, such as trap-assisted Auger recombination. [ABSTRACT FROM AUTHOR]

This study investigated the effects of blue light emitting diode (BLED) irradiation on the quality characteristics of Mukeunji (long‐term fermented kimchi). Mukeunji kimchi broth (MKB) was treated with 460 nm BLED (irradiance 375 J/s∙m2) under refrigerated storage conditions. The effects of BLED irradiation on microbial growth were evaluated over the 3‐day storage period at 4°C. The quality attributes of the MKB, including color, pH, and antioxidant activity, were also assessed during the storage period. No significant difference was observed in the viable counts of lactic acid bacteria between BLED‐treated and BLED‐untreated samples. The yeast and mold counts in the MKB, however, were significantly reduced after 24 hr of BLED treatment at 4°C. The MKB pH significantly increased after 72 hr of BLED treatment at 4°C. The hunter redness (a*) was retained in BLED‐treated samples, whereas the yellowness (b*) was reduced in all samples. After BLED irradiation for 24 hr, significant changes in the 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS) radical scavenging activity of the MKB were also observed. The MJ1 and MJ2 strains isolated from MKB showed high sequence homology with Bacillus paralicheniformis and Bacillus velezensis, respectively, with 99% similarity or more in the phylogenetic tree. Chlorophyll pigment absorbs the blue light emitted by the BLED, so it can partially reduce the growth inhibitory effect of BLED irradiation on the two isolates. These findings suggest that BLED treatment can potentially modulate microbiological growth in Mukeunji during refrigerated storage without significant detriment to its characteristic properties. [ABSTRACT FROM AUTHOR]

Visible blue light emitting diodes (LED) have been studied to inactivate Escherichia coli (E. coli) O157:H7 in agar gels. The LED array was optimized to attain uniform light illumination, and the light intensity distribution was visualized through optical simulation. The uniformity of LED light intensity was assessed, and the evenly spaced array showed the best uniformity with a Petri factor of 0.99. Microbial populations in agar gels prepared with and without a dye were analyzed after light irradiation. Each segment of the gels with different heights was taken to measure microbial reduction, and the results indicated that optical properties, such as opaqueness, played an important role in microbial reduction. The agar gel without and with a dye showed a maximum reduction of <3.4 and <2.1 log CFU/g, respectively. An exposure assessment for E. coli O157:H7 was conducted based on the assumption for the agar gel product after LED illumination. The probability results indicated that a risk (>5 log CFU/g) existed mainly in the bottom layer of the sample, despite the average contamination being <5 log CFU/g. This study provides a suitable approach for designing the LED photoinactivation process and subsequent exposure assessment to avoid risk. [ABSTRACT FROM AUTHOR]

The liquid-liquid interfacial precipitation (LLIP) approach was used to synthesize the C60 fullerene nanowhisker (FNW)-CuS nanoparticle composites utilizing a CuS nanoparticle solution, C60-saturated toluene, and isopropyl alcohol (IPA). Powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the product of C60 FNW-CuS nanoparticle composites. These were also utilized to photocatalytic degradation of rhodamine B (RhB) under blue light emitting diode (LED) irradiation at 450 nm. Also, UV-vis spectroscopy was used to confirm the photocatalytic degradation activity of RhB over the C60 FNW-CuS nanoparticle composites. The percentage of photocatalytic degradation of RhB was shown to be 95.148%. The kinetics study for photocatalytic degradation of RhB using C60 FNW-CuS nanoparticle composites followed a pseudo-first-order reaction rate law. C60 FNW-CuS nanoparticle composites as photocatalyst have a rate constant of 4.82x10-2 min-1 at 25 °C. [ABSTRACT FROM AUTHOR]

Antisolvent treatment is paramount in the fabrication of high‐efficiency perovskite optoelectronic devices as it affords a high crystallization rate critical for the formation of pin holes‐free perovskite films. Although the antisolvent choice determines the domain distribution of quasi‐2D perovskite, and hence the emission wavelength (blue vs green), as well as its light emission efficiency, few studies have examined it in detail. Herein, the crystallization dynamics and resulting optoelectronic properties of PBA (phenyl‐butyl‐ammonium)‐based quasi‐2D perovskites (A′2Am‐1PbmX3m+1), which are commonly employed to create blue emissive films, are scrutinized for the first time through in situ photoluminescence measurements during film formation. The m domain distribution can be tailored by selecting antisolvents with various solubilities of PBA cation. Antisolvents with higher PBA solubility promote the formation of smaller bandgap films due to larger m domains and vice versa. This study effectively reveals a route to tailor quasi‐2D perovskite optoelectronic properties via antisolvent engineering. Fine‐tuning the optoelectronic properties can be done by blending two antisolvents with contrasting PBA cations solubility. By doing so, a blue emissive light emitting diode with emission wavelength ranging from 471 to 509 nm can be fabricated with an external quantum efficiency of 2.9% at 471 nm. [ABSTRACT FROM AUTHOR]

Divalent ions‐doping has recently been developed as a new approach to blue perovskite light emitting diodes (LEDs) with improved spectral stability. However, the efficiency of these perovskite LEDs, especially in the pure blue region, is still far behind their red‐ and green‐emissive counterparts. Here, a method to improve the device efficiency of strontium ion (Sr2+)‐doped pure blue perovskite LEDs, prominently by modifying the hole transport layer, is reported. Mixing a small amount of poly(9,9‐di‐n‐octylfluorene‐alt‐(1,4‐phenylene‐(4‐sec‐butylphenyl)imino)‐1,4‐phenylene) (TFB) into the hole transport layer poly(9‐vinylcarbazole) (PVK) remarkably improves the morphology and reduces the trap states of Sr2+‐doped perovskite films. As a result, a pure blue LED emitting at 470 nm is obtained and shows a high external quantum efficiency of 2.24% with stable electroluminescence spectra under a forward bias of up to 8 V, representing the best performance reported in the divalent ions‐doped pure blue perovskites so far. The work opens up the way for the development of efficient pure blue perovskite LEDs. [ABSTRACT FROM AUTHOR]

The effect of supplemental lighting on strawberry growth and anthracnose disease response of three strawberry (Fragaria ×ananassa) cultivars was evaluated in two greenhouse trials, and the effect on strawberry anthracnose pathogens (Colletotrichum sp.) was evaluated in the laboratory. The objective of the greenhouse trials was to determine the effect of various intensities of the red and blue light emitting diode (LED) light treatment on strawberry plant vigor, injury, and disease development. In these trials, the duration of supplemental light treatments was split into two 4-hour periods: dawn and dusk. The intensity of the red and blue LED bulbs was set using an adjustable dial at 1 or 3 in trial 1 and at 1, 5, or 10 in trial 2. Illuminance and photosynthetic photon flux densities of the light treatments ranged from lows of 402 lx and 5 lmol·m–2 ·s –1 (blue LED 1) to highs of 575 lx and 25 lmol·m–2 ·s –1 (red LED 1 1 blue LED 3) in trial 1, and from lows of 4213 lx and 81 lmol·m–2 ·s –1 (red LED 1) to highs of 7051 lx (red LED 5) and 194 lmol·m–2·s –1 (red LED 10) in trial 2. Lower light intensities in trial 1 resulted in no significant differences as a result of light treatments in relative chlorophyll content, plant vigor ratings, or disease severity ratings (DSRs). However, plant injury ratings were significantly greater in plants in the wide spectrum fluorescent (WSF) plus ultraviolet B (UVB) light treatment compared with the other treatments. Under the higher light intensities in trial 2, there were more significant effects among light treatments. Relative chlorophyll content of plants in the WSF 1 UVB, WSF, and red LED 1 treatments was significantly greater than that of plants in the red LED 10 treatment; however, plants in the red LED 10 treatment had the greatest injury ratings. Detached leaves from plants in the red 5 LED and red 10 LED treatments inoculated with Colletotrichum gloeosporioides received the greatest DSRs, and leaves from plants in the red LED 1 and WSF treatments received the lowest DSRs. In the laboratory, five days of exposure to supplemental lights did not prevent the growth of isolates of three species of Colletotrichum pathogens even though the intensity of the LED lights was set at their highest intensity. However, growth of isolates exposed to the WSF 1 UVB light treatment was slowed. [ABSTRACT FROM AUTHOR]

Light is an important factor in plant growth and morphology of sweet potato (Ipo)moea batatas L. Lam). This study explored the impact of supplemental lighting provided by three commercially available units on a stock plant cutting production and cutting rooting of two sweet potato cultivars ‘Covington’ and ‘Beauregard’. In experiment one, stock plants were grown under one of four lighting conditions, no supplemental light, high blue light emitting diode (LED), low blue LED, or halogen. Cuttings were collected twice a week for 5 wk and the total weekly cutting number and cutting caliper per plant were recorded. During this experiment plants grown under supplemental lighting exhibited significantly greater weekly total cutting numbers after 2 wk of growth when compared with those that were not exposed to supplemental lighting. In experiment two, cuttings were rooted under the same four light treatments and sampled on Days 7, 14, and 21 in which the cutting height, root weight, and shoot weight were recorded. On Day 21 Covington plants grown under low blue and halogen supplemental lighting exhibited significantly greater root dry weight when compared with those that did not receive supplemental lighting. However, no differences in rooting were observed for Beauregard. These results demonstrate that supplemental light increases stock plant growth regardless of the three commercially available light spectrums examined when compared with no supplemental light. This suggests that increasing the daily light integral (DLI) has a larger impact on plant growth than the spectrum of the commercially available lights that were examined. [ABSTRACT FROM AUTHOR]

The exposure to blue and white Light emitting diodes (LED) light leads to damage in the visual system with short-term LED light exposure. Chronic exposure, adaptive responses to light, and self-protective mechanisms against LED light exposures need to be explored, and it would be essential to understand the repercussions of LED radiation on vitreous metabolites. A total of 24 male Wistar rats were used in this study, divided into four groups (n = 6 in each group). Three experimental groups of rats were exposed to either blue, white, or yellow LED light for 90 days (12:12 light-dark cycle routine) with uniform illumination (450–500 lux). Standard lab settings were used to maintain control rats. Vitreous fluids were subjected to untargeted metabolomics analysis using liquid chromatography-mass spectrometry (LC/MS). PLS-DA analysis indicated significant the separation of m metabolites among groups, suggesting that LED exposure induces metabolic reprogramming in the vitreous. Amino acids and their modifications showed significant alterations among groups which included D-alanine, D-serine (p < 0.05), lysine (p < 0.001), aspartate (p = 0.0068), glutathione (p = 0.0263), taurine (p = 0.007), and hypotaurine. In chronic light exposure, the self-protective or reworking system could be depleted, which may decrease the ability to compensate for the defending mechanism. This might fail to maintain the metabolomic structural integrity of the vitreous metabolites. [ABSTRACT FROM AUTHOR]

The results of Cr density during high-current anode modes using broadband absorption spectroscopy are presented. The vapor density of atomic Cr is determined during the formation of anode spot type 1, anode spot type 2, and anode plume. Cr I resonance lines at 425.43 nm are used for the analysis. An AC current pulse with a maximum of about 7 kA and a frequency of 100 Hz is applied. By adjusting the opening time or contact opening speed, anode spot type 1 and type 2 may appear. The temporal evolution of the ground state density of Cr atoms shows about two times higher metal vapor during anode spot type 2 compared with anode spot type 1. The vapor density during an anode plume following anode spot type 2 is also determined and is compared with the same time instant in which no anode plume appears, i.e., only when anode spot type 1 appears. [ABSTRACT FROM AUTHOR]

The article presents a study which reported cerium halides with the cryolite-like structure and stable and tunable color coordinates from (0.17, 0.02) to (0.15, 0.04). Topics discussed include optical characterizations of cerium halides films, synthesis of cerium halides powders, and material and device characterization.

ZrTiO 4 (ZTO) nanoparticles (NPs) are synthesized by solution combustion method using chemical fuel (Glycine) (ZTOG) and green (Aloevera) extract (ZTOA) as a reducing agent (15–25 ml) and calcined at 700 °C. The synthesized samples are characterized and its multi-functional properties such as Photoluminescence, Sensor and Supercapacitor properties were discussed in detail. Powder X-ray diffraction pattern of ZTOG and ZTOA shows the Bragg's reflection corresponding to ZrTiO 4. The pure orthorhombic phase is retained in ZTOA whereas in ZTOG, monoclinic and cubic phases are observed. The crystallite size estimated by PXRD matches well with TEM analysis. From the Wood and Tauc's relation, the energy band gap was found to be 2.8 and 3.2 eV which was further confirmed by band structure using density of states. The photoluminescence emission peaks (λ = 350 nm), CIE and CCT of ZTOA and ZTOG clearly confirms that the present nanophosphor might be a good nanophosphor material for blue light emitting diodes. X-ray/Gamma ray absorption properties are also studied which clearly shows the ZrTiO 4 might be a good absorbing material. Furthermore, Cyclic voltammetry (CV) analysis of ZTOA nanorods shows very good redox peaks as compared to ZTOG. From the Electrochemical Impedance Spectroscopy (EIS) measurements, the charge-transfer resistance for prepared nanorods ZTOA and ZTOG was found to be 180 and 261 Ω respectively. The modified graphite electrode with ZTOA shows good sensing activity for both paracetamol and ascorbic acid rather than ZTOG. [ABSTRACT FROM AUTHOR]

The article presents a study which developed a phosphor-sensitized thermally activated delayed fluorescence (TADF) emission system with TADF emitters to achieve high efficiency and long operational lifetime. Topics discussed include molecule design and photophysical properties, photophysical and electrochemical properties of the emitters, and device performance.

Arrays of nanorod multi-quantum-well (MQW) blue light emitting diodes (nLEDs) with diameter 800 nm were prepared by reactive ion etching (RIE) with subsequent surface treatment by KOH etching alone, and KOH etching followed by SiO 2 passivation with the SiO 2 prepared by the sol-gel technique. In addition, the effects of Ag/SiO 2 core/shell nanoparticles prepared by sol-gel were studied for all surface treatments. For as etched nLEDs, the Internal Quantum Efficiency (IQE) of photoluminescence was low, 5.5 %, because of the impact of surface damage introduced by RIE. KOH etching and KOH plus SiO 2 passivation produced an increase of IQE to respectively 5.7 and 6.8 %. When the Ag/SiO 2 core/shell nanoparticles known to produce localized surface plasmon resonance at the wavelength well-matched to the light emission from the MQWs were added to the polymer filling the gaps between the MQW nanorods, the result was found to depend on finding a proper balance between the enhancement due to the interaction Ag/SiO 2 nanoparticles adjacent to the MQW nanorods and the absorption by "idle" Ag/SiO 2 particles in the bulk of the polymer. When optimal concentrations of LSP NPs giving rise to maximal enhancement of the MQW PL intensity were used, a considerable improvement of performance was obtained, with IQE of 10.6 %. • Arrays of blue light emitting diodes were prepared by reactive ion etching with subsequent KOH etching or SiO 2 passivation. • Effects of Ag/SiO 2 core/shell nanoparticles prepared by sol-gel were studied for all surface treatments. • For as etched nLEDs, the Internal Quantum Efficiency (IQE) was 5.5%. • KOH etching and KOH plus SiO 2 passivation produced IQE of respectively 5.7 and 6.8%. • When optimal concentrations of LSP NPs were used, IQE was 10.6%. [ABSTRACT FROM AUTHOR]

Induced resistance is considered as a sustainable strategy to control postharvest decay of fruits, while light emitting diodes (LEDs) as a green physical technology are of more and more interest in postharvest fruit preservation field. In this study, we evaluated for the first time the resistance inducing ability of LED irradiation with different light wavelengths and photoperiods for cherry tomatoes (Solanum lycopersicum L. 'Qianxi'). Results indicated the exposure to 40 W m-2 of four light wavelengths for 3 d decreased B. cinerea lesion diameter on harvested cherry tomatoes, notably the best effect in blue light (470 nm). Meanwhile, the mechanism of blue light-induced disease resistance is the enhancement of defense-enzyme activity and the expression of defense-related genes. Moreover, results revealed that blue light enhanced vitamin C content and the firmness of the fruit exocarp, suggesting the potential usage of blue light in the postharvest preservation of cherry tomatoes. • LEDs of different wavelengths in inducing disease resistance of fruits were studied. • The best results were obtained by blue light continuously at 40 W m-2 for 3 d. • Blue light enhanced the activities of defense enzymes and antioxidant enzymes. • Blue light maintained soluble solids, vitamin C content and peel hardness. [ABSTRACT FROM AUTHOR]

• CsPbBr 3 nanocrystals were readily prepared on a gram-scale. • Visible-light-induced selective oxysulfenylation of alkenes. • Diverse substituted β -hydroxysulfides and β -oxosulfides with high efficiency and regioselectivity were obtained. • Investigations were carried out to reveal the mechanism. Lead halide perovskites are promising candidates for efficient phtocatalysts in organic synthesis due to their attractive properties in light absorption, photogenerated charge transportation, and utilization. We report herein the development of photoinduced selective oxysulfenylation of alkenes using CsPbBr 3 nanocrystals that is visible light-responsive, easy-to-prepare, and cost-effective. Under blue light-emitting diode (LED), a series of alkene substrates are demonstrated to be highly efficient reaction partners to couple with disulfides tolerated with various functional groups, affording diverse β -hydroxysulfides and β -oxosulfides with excellent yields and high selectivity. Mechanism investigation shows that the visible-light induces the generation of thiyl radicals to initiate the reaction, followed by radical addition and oxygenation to form hydroperoxy sulfides intermediate, which selective convert to β -oxo sulfideos and β ‑hydroxy sulfides. The work provides a new exploration of the rational utilization of CsPbBr 3 nanocrystals to achieve selective oxysulfenylation of alkenes, displaying the great potential of perovskites for radical chemistry via photocatalysis. [Display omitted] The photoinduced selective oxysulfenylation of alkenes has been developed by using CsPbBr 3 nanocrystals that is visible light-responsive, easy-to-prepare, and cost-effective, in which the heterogeneous photocatalyst can be recycled at least five times without a substantial decrease in photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

Non‐toxic heavy metal, low‐cost indium‐free blue emissive quantum dots (QDs) are critical for the realization of self‐emissive electroluminescent quantum dot (ELQD) light‐emitting diode (LED) displays. A facile and effective hybridization of ZnO QDs with functionalized polyaromatic hydrocarbons (f‐PAHs) to synthesize a very bright and stable blue‐light emissive quantum‐dot LED (QLED) using non‐toxic quasi‐type‐II ZnO@1‐Aminopyrene hybrid QDs is reported. The optimized QLEDs of ITO/PEDOT:PSS/TFB/ZnO@1‐Aminopyrene/TPBi/LiF/Al demonstrate very bright deep blue‐light electroluminescence of 3379 cd m−2 centered at λ = 441 nm with a full‐width‐at‐half maximum of 41.7 nm and CIE 1931 color coordinates of 0.17 and 0.09, a luminous efficacy of 3.32 cd A−1, power efficiency of 2.45 lm W−1, external quantum efficiency of 2.35%, and a remarkably long lifetime T50 of >17 830 h at 100 cd m−2. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The self‐assembled metal halide perovskite (MHP) nanocrystal superlattices have attracted many researchers due to their exceptional optical and electrical properties. The bottom‐up self‐assembly can be facile to generate ideal and periodic structures. The superlattices' stability can be improved and the photoluminescence lifetime can be extended by an order of magnitude. However, due to lack of a comprehensive and systematic understanding of the internal interactions on self‐assembled processes now, superlattices cannot be obtained controllably and play full use of their advantages. Therefore, gaining a deep insight of interaction forces about self‐assemblies is the premise of designing and controlling the degree of self‐assembly so as to prepare ideal materials. In this review, the definitions and functions of driving forces including van der Waals forces, electrostatic interactions and hydrogen bonds are discussed. Subsequently, we aim to explore the dominant factors affecting the driving forces, which can make a difference in the process of MHP self‐assembly. Based on current researches, we emphasize on three aspects−the core of nanocrystals, surface ligands and solvents−to clarify their critical roles in controlling the driving forces. Finally, the outlooks and perspectives of how to facilitate the MHP self‐assembly and their application on blue light emitting diodes are discussed. [ABSTRACT FROM AUTHOR]

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Simulations on mobility influence in optoelectronics parameters from an InGaN/GaN blue LED using the Nextnano++ software arepresented in this paper. These simulations were performed by changing the hole and electron mobility value for the material compounds according to experimental, theoretical, and doping-concentration data already reported in the literature. The power law mobility is used for the current calculation in the quantum drift-diffusion model. The results indicate the lower hole and electron leakage currents correspond to the lowest mobility values for the InGaN alloy, the greatest amount of recombination occurs in the extreme wells within the active layer of the LED and the stable emission is at 3.6 V with peak wavelength λ ^ L E D = 456.7   nm and full width at half maximum F W H M ~ 11.1   nm for the three mobilities. Although experimental and theoretical mobility values reach higher carrier density and recombination, the photon emission is broader and unstable. Additionally, the doping-concentration mobility results in lower wavelength shifts and narrows FWHM, making it more stable. The highest quantum efficiency achieved by doping-concentration mobility is only in the breakdown voltage ( η d o p − m a x = 60.43 % ), which is the IQE value comparable to similar LEDs and is more useful for these kinds of semiconductor devices. [ABSTRACT FROM AUTHOR]

In the current study Sr(NO3)2 and Al(NO3).H2O were used in the urea fuel combustion method to synthesise the Eu² pure SrAl2O4 (SA Pure) and Eu2+, Dy3+ co-doped Sr1-xAl2O4 phosphor (SAE5D1 phosphor). It was discovered to be single phased in nature and to have crystallised into monoclinic phase with the typical JCPDS 34-0379 card after a structural analysis using XRD. Since the sample is a broad band gap material, the optical band gap for Eu2+, Dy3+ doped Sr1-xAl2O4 phosphor (SAE5D1 phosphor) in the current situation is 3.99 eV. Scanning electron microscopy and transmission electron microscopy were used for the morphological research. Transmission electron microscopy indicates that the majority of the particles are irregular spherical grains with a mean size of 30-41 nm. The photo-luminescence studies found that it exhibits broad emission spectra using an excitation wavelength of 365 nm. The Eu2+, Dy3+ doped Sr1-xAl2O4 phosphor (SAE5D1 phosphor), which has a colour correlated temperature (CCT) of 8325 K, colour rendering index (CRI) of 82, colour purity of 14.86%, high visible W values 36180660000 mW may be set to emit blue (0.2839, 0.3247) light. The spectra are in the visible range and quite brilliant. The broad emission spectrum might be viewed as a different method of obtaining direct blue emission for blue light emitting diodes and other optoelectronic devices used in the medical field. [ABSTRACT FROM AUTHOR]

In this paper, the main aim is to study, simulate and investigate a basic Underwater Optical Wireless Communication System in a direct line of sight (LoS) configuration for different water types i.e. clear seawater and turbid water. In these conditions blue Light Emitting Diode (LED) based transmitter is compared with a blue laser-based transmitter for Non-Return to Zero On–Off keying (NRZ-OOK) modulation. The variations of Q-Factor, minimum Bit Error Rate (BER), Signal power, and Signal to Noise ratio (SNR) are studied with variable distance and variable bit rate. The system performance is analysed by visualising the eye diagrams. This study also emphasises the selection of a suitable frequency of light that can traverse the channel with minimum path loss and a compatible bit rate. [ABSTRACT FROM AUTHOR]

The bilayer structure for an emitting layer (EML) was developed to improve performances of a fluorescence blue organic light emitting diode. By functionally separating the EML into the charge recombination and the Triplet‐Triplet Fusion (TTF) zone, we successfully suppressed the quenching of triplet excitons by excess carriers to make more TTF efficient and the local degradation within the EML to make the lifetime longer. In the bottom emission device with the bilayer EML, 12% of external quantum efficiency (EQE) and 450 hours of LT95 were achieved. Furthermore, we achieved over 14% of EQE by optimizing the material combinations. [ABSTRACT FROM AUTHOR]

All inorganic cesium lead trihalide nanocrystals are promising light emitters for bright light emitting diodes (LEDs). Here, CsPb(BrCl)1.5 nanocrystals in metal-organic frameworks (MOF) thin films are demonstrated to achieve bright and stable blue LEDs. The lead metal nodes in the MOF thin film react with Cs-halide salts, resulting in 10-20 nm nanocrystals. This is revealed by X-ray scattering and transmission electron microscopy. Employing the CsPbX3-MOF thin films as emission layers, bright deep blue and sky-blue LEDs are demonstrated that emit at 452 and 476 nm respectively. The maximum external quantum efficiencies of these devices are 0.72% for deep blue LEDs and 5.6% for sky blue LEDs. More importantly, the device can maintain 50% of its original electroluminescence (T50) for 2.23 h when driving at 4.2 V. Detailed optical spectroscopy and time-of-flight secondary ion mass spectroscopy suggest that the ion migration can be suppressed that maintains the emission brightness and spectra. The study provides a new route for fabricating stable blue light emitting diodes with all-inorganic perovskite nanocrystals. [ABSTRACT FROM AUTHOR]

The bilayer structure for an emitting layer (EML) was developed to improve performances of a fluorescence blue organic light emitting diode. By functionally separating the EML into the charge recombination and the triplet–triplet fusion (TTF) zone, we successfully suppressed the quenching of triplet excitons by excess carriers to make more TTF efficient and the local degradation within the EML to make the lifetime longer. In the bottom emission device with the bilayer EML, 12% of external quantum efficiency (EQE) and 450 h of LT95 were achieved. Furthermore, we achieved over 14% of EQE by optimizing the material combinations. [ABSTRACT FROM AUTHOR]

Anti-blue light films with high transparency and low haze that completely originate from renewable and biodegradable biomass materials for eye protection is a growing trend with great demand in the near future. Therefore, in this study, a natural bioactive ingredient, lutein, was incorporated into the cellulose matrix via a green and facile adsorption strategy to prepare biodegradable ultraviolet (UV) and blue light filters. The lutein/carboxymethylated cellulose films (L-CCFs) displayed high anti-UV capacity, with UV-A and UV-B blocking ratios of 52.7 %-90.9 % and 44.1–85.2 %, respectively. The composite films could block 83.1–97.8 % of blue light in the 400−500 nm region while maintaining high transparency (86.6–89.3 %) and low haze (2.1–2.6 %). By light absorption, the films can effectively shield blue light emitted by light-emitting diodes, sunshine, lighting systems, mobile phone, and computer screens. Quite encouragingly, the addition of lutein significantly increased the water contact angle from 40.1 to 70.5° and the composite films have excellent liquid barrier properties. Meanwhile, these films exhibit higher light stability than lutein powders, thus greatly extending the service life of the film as a blue light shielding material. Moreover, the films have excellent mechanical strength (>110 MPa) and biodegradability. These films prepared entirely from natural resources offer great application value in the fields of electronic screen films and spectacle lenses. [Display omitted] • High tensile strength lutein-cellulose films were prepared for eye protection. • Lutein-cellulose films demonstrated UV and blue light double-blocking capacity. • Lutein-cellulose films exhibited high optical transmittance and low haze. • Compositing with lutein could improve water contact angle of films. [ABSTRACT FROM AUTHOR]

• Zinc gallate was synthesized by Bio mediated route using Leucas aspera extract. • Structural, Phase diagram, Optical and Latent fingerprint analysis was performed. • The might be a potential candidate for display technology, cool blue light emitting diodes, florescence boards and in forensic science. [Display omitted] For the first time, Zinc Gallium Oxide is synthesized using L e u c a s A s p e r a leaves extract as a reducing agent followed by the calcination at 500 ∘ C. The structural, morphological, and optical properties are discussed. The Bragg reflections confirm that ZGO gets crystallized in pure cubic form. The surface morphology consists of agglomerated NPs. The direct energy band gap was found to be 3.1 eV. The photoluminescence analysis excited under 233 nm, and CIE values fall in the blue region of visible spectra. The CCT value was found to be 2748 K which might find an application as a nanophosphor in warm light-emitting diodes. Further, the powder dusting method was employed to collect the latent fingerprints (LFPs) on the pores and non-pores surfaces under UV as well as in day light. The synthesized ZGO exhibits well-resolved ridge patterns that can be used to identify LFPs with clarity. From all these results, the present synthesized ZGO NPs might find an application in display technology as a blue nanophosphor material and for LFP detection in crime investigation. [ABSTRACT FROM AUTHOR]

To investigate the effects of trifluoromethyl and tert -butyl moieties on the general optoelectronic properties of star-shaped hosts based on phenyls substituted carbazole, we used 3,6,9-tris (4-(tert -butyl)-phenyl)-9 H -carbazole (M1) as a reference, and different numbers of electron-withdrawing 3,5-bis(trifluoromethyl) benzene were introduced into 3, 6 and 9 positions of carbazole to obtain compounds 9-(3,5-bis(trifluoromethyl)phenyl)-3,6-bis(4-(tert -butyl)phenyl)-9 H -carbazole (M3) , 3,6-bis(3,5-bis(trifluoromethyl)phenyl)-9-(4-(tert -butyl)phenyl)-9 H -carbazole (M5) and 3,6,9-tris(3,5-bis(trifluoromethyl)phenyl)-9 H -carbazole (M6). After the introduction of 3,5-bis (trifluoromethyl) benzene, the thermal temperature at 5 % mass loss of M3 , M5 and M6 decreased to 344 °C, while the glass transition temperature and melting point of M3 and M5 showed a significant increase. However, M6 did not show obvious glass transition, but its melting point also showed a significant increase. M3 crystallized at 125 °C as evidenced by differential scanning calorimetry, and the linking model of M3 is helpful to crystalize. In addition, when compared with those of M1 , the fluorescence emission peaks of M3 and M6 showed a blue-shift, while M5 showed a red-shift, all of which were in the deep blue emission range. The color purity of blue light for M1 in tetrahydrofuran solution is the highest, and M1 exhibit aggregation-induced emission characteristics. Compared to the photoluminescence quantum efficiency (PLQY) of compound M1 of 39 % in toluene, the PLQYs of M3 and M6 decreased to 34 % and 29 %, and the PLQY of M5 increased to 46 %. The function of the lowest unoccupied molecular orbital trap of M3 film under the external electrical field will increase, which not only offsets the increasing effect of the electrical field to the electron carrier and further decreases the carrier mobility when the electrical field increase, and the same situation is also feasible for the highest occupied molecular orbital traps in M5 , M6 and M1. The organic blue light emitting diodes were prepared by using M1 , M3 , M5 and M6 as the hosts of bis [2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium, and the optimized device of M1 as the host showed the best performance with a maximum luminescence brightness of 2978 cd/m2, maximum current efficiency of 39.42 cd/A and maximum external quantum efficiency of 18.36 %. • Trifluoromethyl decreased the thermal-stability of the hosts. • 3,5-bis(trifluoromethyl) benzene tri-substituted host emitted light more effectively. • 3,5-bis(trifluoromethyl) benzene improved the electron-injecting ability of the hosts. • 3,5-bis(trifluoromethyl) benzene mono-substituted M3 made the charge mobilities to change oppositely relative to the others. • M1 without 3,5-bis(trifluoromethyl) benzene showed aggregation-induced emission characteristic and better device performance. [ABSTRACT FROM AUTHOR]

MgO-ZnO-Ga 2 O 3 nanocomposites are synthesized by solution combustion method using Aloe Vera gel as a reducing agent to increase the efficiency of blue emission. The appearance of Bragg reflections corresponding to MgO, ZnO and Ga 2 O 3 clearly indicates the formation of nanocomposites. The surface morphology consists irregular shape and sized NPs. The Energy dispersive X-ray analysis confirms the purity of the sample. The band energy gap was tuned to 3.1 eV. The Photoluminescence excitation and emission spectra was discussed and compared it with emission spectra of individual oxides as well as with other reported blue emitted nanophosphors. Further, the chromaticity coordinates and Color correlated temperature coordinates clearly confirms their warm blue emission. Further, the powder dusting method was employed to collect the latent fingerprints on the pores and non-pores surfaces. The synthesized MgO-ZnO-Ga 2 O 3 nanocomposites exhibits well-resolved ridge patterns that can be used to identify latent finger prints with clarity. From all these results, the present synthesized MgO-ZnO-Ga 2 O 3 nanocomposite might find an application in display technology as a blue nanophosphor material and for latent finger print detection in crime investigation. [Display omitted] • Mgo-ZnO-Ga 2 O 3 nanocomposite was synthesized by Bio mediated route using Aloe Vera extract. • Structural, Phase diagram, Optical and Latent fingerprint analysis was performed. • The might be a potential candidate for display technology, cool blue light emitting diodes, florescence boards and in forensic science. [ABSTRACT FROM AUTHOR]