Lighting Applications Research Articles

Investigating the physicochemical, optical and microstructural properties of sodium doped CdO nano powders fabricated by co-precipitation technique for blue emission and antimicrobial applications

A series of cubic structured pristine and sodium doped CdO nanoparticles (Cd1-xNaxO NPs) with varying dopant concentrations have been synthesized using simple Co-precipitation process. Crystal structure and the connection between various structural parameters are evidenced using powder XRD diffractograms. The crystallite size is evaluated with different models and the mean crystallite size was reduced with Na ions doping concentration due to severe lattice distortion. The existence of various vibrational modes and functional groups were demonstrated through FTIR characterization. The signature of Cd–O and Na–O stretching modes were confirmed with FTIR. Raman spectra also confirmed the formation of metal–oxygen bond and the second order vibration features. The direct bandgap of the CdO material increased from 2.132 to 2.40 eV with an increase in the Na dopant content which presents the appearance of a blue shift as probed through UV–Vis spectroscopy. The surface morphology and microstructure of the samples were studied using FESEM and HRTEM images, respectively. EDAX measurements revealed the presence of Cd, and O in the host lattice and Cd, O and Na in the doped CdO constructions. The SAED concentric ring pattern of Cd1-xNaxO nanoparticles demonstrated the polycrystalline nature of the samples. PL study revealed the impression of intrinsic defects and the photoluminescence colour emission of the Cd1-xNaxO materials shifted more towards bright blue region as the Na doping concentration increased. CIE color coordinates of Na-doped CdO NPs shows intense bluish color and extending its applications in commercial UV lighting, blue LEDs and Fluorescent biological labelling and tagging. Cd1-xNaxO nanoparticles exhibited enhanced antibacterial activity with increasing Na doping content towards gram-positive, and gram-negative bacteria. Further, the antifungal analysis against C. albicans, and A. niger authenticate that Na+ substituted CdO nanoparticles shows excellent antifungal activity. The mechanism of the above observed results is examined in detail in this article.

Intense red emission from trivalent Eu3+ doped Ca9La(VO4)7 nanophosphor for lighting and latent fingerprinting applications

Intense red emission from trivalent Eu3+ doped Ca9La(VO4)7 nanophosphor for lighting and latent fingerprinting applications

PV integrated multi-leg powered constant quasi-dynamic charging system for low-speed vehicles

The global adoption of electric vehicles (EVs) is gaining momentum as countries strive to achieve sustainable development goals. Establishing charging infrastructure is of paramount importance to promote increased EV usage. The cost and weight of the batteries are factors that reduce the sales volume and popularity of EVs. A dynamic charging system has also been developed to enhance the driving range of EVs and mitigate the need for heavy storage requirements. The energy demand of charging infrastructure is increasing day by day. Many countries are installing solar arrays along the roadside to meet the power demand of highway lighting applications and achieve sustainable development goal (SDG) 7. To further enhance this system, this manuscript proposes integrating PV technology with the dynamic charging system. The PV arrays and energy storage system (ESS) collaborate to power the dynamic charging system. A multi-leg inverter is employed to energize the charging couplers, while a resonant network improves the power transfer capability of the couplers. On the receiver side, a resonant network ensures the delivery of constant voltage and constant current by tuning the network topology. The 3.3 kW five-legged inverter is developed to energize the four double-D-shaped charging couplers. The common DC bus delivers 350 V to the inverter, and the charging system delivers 350 V, 8.85 A to the EV batteries.

A Ripple Free Soft-Switched Integrated Series Resonant Converter for Main and Local LED Lighting Application

A Ripple Free Soft-Switched Integrated Series Resonant Converter for Main and Local LED Lighting Application

Synergistic effects of zinc thiocyanate on the performance of cesium lead bromide perovskite phosphors for solid-state lighting applications

All inorganic lead halide perovskites have led to a new paradigm shift in display and lighting technologies because of significant cost and performance advantage over the current state-of-the-art optoelectronics. However, the applications of these perovskites are undermined due to the toxicity and severe degradation of the materials in response to external stimuli. This research highlights the synergetic effects of co-doping of CsPbBr3 nanocrystals (NCs) at its B- and X-site using zinc thiocyanate (Zn(SCN)2). The adopted doping strategy helps to improve the photoluminescence stability of the pristine NCs when stored under ambient conditions for 156 days. This is attributed to the enhanced local structural order and reduced inhomogeneous strain between the lattices of the NCs due to the synchronized effect of Zn2+ and SCN–. The composite NCs are integrated as color-converting layers (thin 3D printing layer coated with NCs) with a blue LED chip to obtain the white light. It exhibits bright white emissions with a color rendering index of 86, correlated color temperature of 6046 K, and color coordinates close to standard white light. This work emphasizes the strong potential of inexpensive and earth-abundant Zn(SCN)2-based CsPbBr3 composites to meet consumer needs.

Regulating ligand length to improve the PL QY and stability of CsPbCl0.9Br2.1 nanocrystals for LEDs and photoelectric applications

Perovskite luminescent materials have been extensively investigated due to their comprehensive applications for full-color display, lighting, and communication. However, the development of blue-emissive perovskites has seriously lagged behind that of green and red counterparts, primarily because of their low photoluminescence quantum yield (PL QY) and poor stability. Here, we prepared blue-emissive CsPbCl0.9Br2.1 perovskite nanocrystals (PeNCs) and enhanced their QY from 61.3 % to 90.4 % by regulating the chain lengths of ligands. Post-treated PeNCs also exhibit good stability, their PL intensity is maintained at about 90 % after storage at ambient conditions for 10 days. The exciton dynamics results obtained from time-resolved fluorescence spectra and transient absorption spectra show that dodecyldimethylammonium bromide (DDAB), featuring double 12-hydrocarbon chains, is more capable of passivating surface defects and inhibiting non-radiative composites than the other double 8- or double 16-carbon chain ligands, which greatly improved the probability and rate of radiative recombination. Subsequently, the mechanism of ligand chain length regulation on the PL properties and stability of PeNCs was analyzed in terms of ligand-NC surface interaction, ligand polarity, hydrophobicity, and spatial effects. Furthermore, the device based on DDAB-CsPbCl0.9Br2.1 demonstrated stable EL and long operation lifetime, indicating its significant potential as an efficient blue emitter for backlighting in display technologies.

Probing the Operation of Quantum-Dot Light-Emitting Diodes Using Electrically Pumped Transient Absorption Spectroscopy.

The quantum-dot light-emitting diode (QLED) is a new generation light emission source that holds great promise for display and lighting applications. Understanding the dynamics of electrons and holes in QLEDs during their operation is crucial for future QLED optimization, but a time-resolved technology capable of characterizing electrons is still lacking. To tackle this challenge, we develop a unique electrically pumped transient absorption (E-TA) spectroscopy to probe the density of electrons in the QD layer with a nanosecond time resolution. The E-TA result provides a comprehensive understanding of the electron dynamics in QLEDs by quantifying the electron injection time after external voltage on, electron release time after external voltage off, and equilibrated electron density (Ne) in the QD layer during device operation. By combining E-TA technology with time-resolved electroluminescence and transient current measurements, we present a comprehensive overview of the dynamics of both electrons and holes in a QLED during operation.

Synthesis and color-tunable emission of ZnGaOx with different cation ratios by a polyacrylamide gel method

ZnGaOx nanoparticles with varied ratios of Zn2+ to Ga3+ were synthesized by a polyacrylamide gel route. The phase purity and structure are confirmed by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR) and X-ray photoelectron spectrometer (XPS). High crystal quality and elemental distribution are determined by transmission electron microscopy (TEM) measurements. The band gaps of the samples ranging from 3.22 to 4.47 eV are estimated by ultraviolet–visible (UV–Vis) diffuse refectance spectroscopy (DRS). Under the excitation of 325 nm laser light, ZnGaOx nanoparticles with the Zn2+/Ga3+ molar ratios of 0.8:2 and 0.7:2 show two emission peaks at 415 and 510 nm. A marked emission band at 695 nm is observed from the samples with Zn2+/Ga3+ molar ratios of 0.6:2, 0.5:2 and 0.4:2. The luminescence mechanism is discussed based on the experimental results. The luminescence color of as-synthesized samples gradually shifts from blue-green to green-yellow region with decreasing Zn2+/Ga3+ ratio. Interestingly, the sample with Zn2+/Ga3+ ratio of 0.7:2 has the CIE chromaticity coordinates of (x = 0.26, y = 0.33) close to the coordinates (x = 0.33, y = 0.33) of pure white light. Together, ZnGaOx phosphors with different emission colors without doping with rare earths have considerable potential applications in tunable light emitting diodes (LEDs) and color display.

Comparative study on lubrication properties of biodiesel and bio-lubricant trans-esterified from desert seed oil with conventional lubricants

In recent years, there has been an increasing focus on renewable and biodegradable energy sources among lubricant manufacturers due to the environmental impacts and limited availability of fossil-based engine oils. Biomass sources present a cost-effective and eco-friendly alternative to traditional mineral oil sources. This study aims to produce and characterize biodiesel and biolubricant from desert date seed oil through transesterification. The result of the study was compared with the properties of conventional and commercial lubricants. The study employed transesterification to convert desert date seed oil into biodiesel and biolubricant. The produced biolubricant and biodiesel were characterized to determine their kinematic viscosity at 40°C, specific gravity, flash point, and pour point. These properties were then compared with those of other bio-lubricants and commercial base lubricants. For biodiesel, the yield was 56%, with a favorable acid value (0.98 mg KOH/g), iodine value (43.41 mg/g), and saponification value (197.4 mg KOH/g). Although, the specific gravity (1.876) was higher than ASTM standard. However, the flash point (112°C) and cloud point (11°C) were within acceptable ranges. The biolubricant produced from desert date oil showed promising results with a high kinematic viscosity of 67.54 mm2/s, a specific gravity of 1.876, a flash point of 120°C and a pour point (−5°C). These results obviously suggest the produced lubricant a suitable for automotive applications possessing good low-temperature performance. The flash point result and the physicochemical properties of the oil aligned well with industrial standards. The comparisons revealed that the produced biolubricant closely matched the properties of SAE VG 220 and SAE VG 40. The findings suggest that the biolubricant and biodiesel derived from desert date seed oil can serve as a viable substitute for petroleum-based lubricants in light gear applications and can be effectively used in two-stroke engines, providing a sustainable alternative to conventional lubricants.

Low blue-hazard white-light emission based on color-tunable triplet-triplet annihilation upconversion

The commonly used artificial light sources, such as fluorescent lamps and white light-emitting diodes, often have a high ratio of blue light emission, which poses potential blue light hazards, especially one of the main culprits leading to eye diseases. Therefore, developing novel white lighting sources with low blue-hazard is highly appreciated. In this work, an air-stable and color-tunable triplet–triplet annihilation upconversion (TTA-UC) mechanism was proposed to realize the low blue-hazard white-light emission. The proposed design was composed of three primary RGB colors from the annihilator (9,10-diphenylanthracene, DPA), the laser excitation source, and the photosensitizer (palladium (II) octaetylporphyrin, PdOEP), respectively. The introduction of oil-in-water (o/w) microemulsion can effectively block the potential oxygen-induced triplet-quenching and benefit high UC efficiency. Moreover, either raising ambient temperatures or adding isobutanol can activate the UC process to yield white-light emission. Notably, the white-light emission with a Commission Internationale de l’Eclairage (CIE) coordinate of (0.33, 0.33) as well as a low ratio of blue emission (14.2 %) was achieved at an ambient temperature of 42 °C. Therefore, the proposed air-stable TTA-UC mechanism can significantly lower the blue-hazard and provide a novel solution for applications in lighting and display.

Microwave synthesis of composite of AgInS2 quantum dots and zeolitic imidazolate framework-8 for application in white light emitting diodes

Preparation of AgInS2 quantum dots (AIS QDs) with high photoluminescence quantum yield (PLQY) and thermal stability remains an important challenge. In this paper, AIS QDs were successfully introduced into zeolitic imidazolate framework-8 (ZIF-8) by microwave-assisted hydrothermal method. Due to the effective isolation of the ZIF-8, the AIS QDs avoid the concentration quenching when they were assembled into white light emitting diodes (WLEDs) devices as color conversion materials. More importantly, the generation of ZnS layer between the interfaces of AIS QDs and ZIF-8 can efficiently improve the optical performance of AIS QDs, resulting in the fluorescence lifetime extended to 470.05 ns. Meanwhile, the PLQY of AIS/ZIF-8 composite reached up 34.30 % when microwave hydrothermal heating at 120 °C for 60 min with AgIn/Zn=1/3, which was higher than that of the pristine AIS QDs as 25.30 %. Finally, the WLED devices were fabricated by combining AIS/ZIF-8 composite fluorescent powder with (Ba, Sr)Si2O2N2:Eu2+ phosphors and blue LED. At 20 mA, the AIS/ZIF-8 based WLED shows the luminous efficiency (LE) of 44.54 lm/W, correlated color temperature (CCT) of 4242 K and color rendering index (CRI) of 89.1. Moreover, the Commission International de L'Eclairage (CIE) was (0.36, 0.35), indicating the WLED emited warm white light. The present strategy aims at enhancing the optical performance of AIS QDs, which also may trigger the development of QDs-based WLED.

Isomorphism of Sr[Li3AlO4] and Sr[Li3GaO4] - Syntheses, Crystal Structure, and Europium(II) Luminescence.

While highly efficient red-emitting inorganic phosphors have been discovered in the substance class of alkaline earth oxo(nitrido)lithoaluminates, new narrow-band green- and yellow-emitting components are being sought to improve the performance of phosphor-converted light-emitting diodes (pc-LEDs). Various solid-state reactions were carried out under protective gas atmosphere in nickel crucibles and sealed tantalum ampules to synthesize Sr[Li3AlO4], Sr[Li3GaO4], and five substitutional derivates of Sr[Li3(Al1-x Ga x )O4] at moderate temperatures. The observation of a linear increase in the unit cell parameters as a function of the increasing gallium mole fraction x in Sr[Li3(Al1-x Ga x )O4] revealed Vegard behavior in the solid-solution series, which was derived from powder X-ray diffraction data. The isomorphic crystallization of the new oxolithogallate Sr[Li3GaO4] and the known oxolithoaluminate Sr[Li3AlO4] in an ordered variant of the U[Cr4C4] aristotype was verified on the basis of powder and single-crystal X-ray diffraction data. Photoluminescence spectroscopy was used to investigate the narrow-band emissions in the substitution series of Eu2+-activated Sr[Li3(Al1-x Ga x )O4] under blue-light excitation. The emission maximum was shifted to higher energies as the gallium mole fraction increased. Peak wavelengths were observed at λem = 572 nm (fwhm equals 47 nm, 1446 cm-1, 0.18 eV) for yellow-emitting Sr[Li3AlO4]:Eu2+ and at λem = 554 nm (fwhm equals 49 nm, 1589 cm-1, 0.20 eV) for green-emitting Sr[Li3GaO4]:Eu2+. Sr[Li3AlO4]:Eu2+ has excellent thermal quenching resistance with a photoluminescence emission intensity of >93% at T = 423 K relative to the room temperature value, making this inorganic phosphor a potential candidate for solid-state lighting applications.

The Application of Intelligent Lighting in Thermal Power Plants

With the rapid development of electronic information technology, the Internet of Things (IoT), Internet technology, and modern communication technology, people are demanding higher standards for the building environment. Especially in modern large-scale buildings with high levels of industrialization, lighting systems should also be optimized accordingly. This article explores the application path of intelligent lighting in thermal power plants for reference.

Spectroscopic assessments on Sm3+ ions doped phospho-borate glasses mixed with fluoride modifiers for the applications of reddish-orange visible light

Sm3+ions doped Phospho-Borate glasses were synthesized and their physical and spectroscopic parameters were studied to evaluate its potential reddish-orange emission for photonic applications. Structural investigation made through XRD analysis confirms the amorphous nature. The evaluated bonding parameters from the absorption spectral analysis confirm the ionic bonding of the Sm–O network in the prepared glasses. Four emission bands were observed from the luminescence spectra, and the HT 4G5/2 → 6H7/2 is observed at 601 nm. The oscillator strength values elucidate the intensity of the absorption bands, and the PBKZnF:Sm sample exhibits a higher oscillator strength value. The Judd-Ofelt intensity parameters were observed to trail the trend Ω4 > Ω6. > Ω2 for the majority of the samples. The CIE 1931 color chromaticity investigation confirms that the present glass samples are suitable for reddish-orange media. Barium and strontium-incorporated glasses exhibit outstanding lasing potential, which was confirmed through the efficiency of the quantum yield and some of the radiative parameters like effective bandwidth, transition probability and stimulated emission cross-section. Radiative parameters have been calculated from the luminescence spectra. Amid all transitions, 4G5/2 →6H7/2 transition has higher transition probability and higher stimulated emission cross-section values for all the prepared glass samples. Barium-incorporated glass exhibits a higher emission cross-section of 30.55 × 10−22 cm2 and a transition probability of 30.89 s−1 compared to all other glasses. The non-exponential decay profiles of the fabricated samples were plotted by examining the excitation wavelength at 402 nm and emission wavelength at 600 nm. Of all the prepared glasses, the quantum efficiency is found to be higher for the glass sample PBKSrF:Sm (65 %).

Structural and LuminescentProperties of Dy(III) DopedCa0.5Bi3P2O10 Nanophosphors for Solid-State Lighting& Latent Fingerprinting Applications.

Anefficient urea-assisted SC (solution-combustion)approach was used to synthesize a novel series ofdoped Ca0.5Bi3P2O10: xDy3+ nanophosphors (0.01-0.1mol). The powdered materials were thoroughly investigated using structural and optical measures. 'Rietveld refinement'investigations found that the produced nanophosphorformed a triclinic system with the P -1 triclinic space group. An EDS (energy-dispersive spectral)study was conducted to determine the corresponding proportions of constituentelements of doped nanophosphors. The TEM (transmission electron microscopy)revealed aggregated particles with a standard size onthe nanoscale. The PLE (Photoluminescence excitation)spectrum indicates that the indicated phosphors can be stimulated by NUV (near ultraviolet)illumination sources. The Dy3+-ions undergo transitions from (4F9/2 → 6H15/2 & 4F9/2 → 6H13/2) were recognized as (PL) spectra with an excitation of 353nm revealed the presence of blue-yellow bands at 481, and 577nm, correspondingly. Further, PL data was used to determine photometric metrics such as CCT (correlated color-temperature), CC (chromaticity-coordinates (x &y)), and CP (color-purity (%)), supporting their use in solid-state lighting and latent fingerprinting applications.

(Invited) A CNT Binding Bis(Zinc Porphyrin)Bodipy-C60 Nano Tweezer: Charge Stabilization in Supramolecular C60-Bodipy-(ZnP)2:SWCNT Hybrids

Single-wall carbon nanotubes (SWCNT) coupled with either electron donor or acceptor are promising functional structures for light energy harvesting and molecular optoelectronics applications. For building such hybrids involving SWCNTs, the p-stacking ability of large aromatic compounds is one of the commonly employed approaches.1-2 Often, the desired donor or acceptor entities are functionalized to carry one or more aromatic entities and allowed to interact with CNTs. However, due to close proximity, the role of SWCNTs in stabilizing the electron transfer product has been a challenge.3 Recently, we overcame this hurdle by employing a multi-modular approach to build donor-acceptor hybrids and successfully demonstrated charge stabilization in the presence of SWCNTs.4 In the present study, we have further improved our design by newly synthesizing a nano tweezer comprised of covalently linked BODIPY-C60 carrying two zinc porphyrin arms as shown in the figure. This compound was further allowed to interact with SWCNT(6,5) and SWCNT(7,6) to form the supramolecular C60-BODIPY-(ZnP)2:SWCNThybrids. Upon spectral, electrochemical, and computational characterization, femtosecond pump-probe spectroscopic studies were performed to establish the occurrence of photoinduced charge separation and charge stabilization. Extending the lifetime of the charge-separated states upon SWCNT binding has been successfully demonstrated in the present molecular design strategy. D’Souza, F.; Sandanayaka, A. S. D.; Ito, O. ‘SWNT-Based Supramolecular Nanoarchitectures with Photosensitizing Donor and Acceptor Molecules’ Phys. Chem. Letts. 2010, 1. 2586-2593.B. KC, G. N. Lim, and F. D’Souza, ‘Accelerated Charge Separation in Graphene Decorated Multi-Modular Tripyrene-Subphthalocyanine-Fullerene Donor-Acceptor Hybrids,’ Angew. Chem. Int. Ed. 2015, 54, 5088-5092.Barrejon, L. M. Arellano, F. D’Souza, F. Langa, ‘Bidirectional charge transfer in carbon-based hybrid nanomaterials’ Nanoscale, 2019, 11, 14978-14992.Kazemi, Y. Jang, A. Liyanage, P. A. Karr, and F. D’Souza, A Carbon Nanotube Binding Bis(pyrenylstyryl)BODIPY-C60 Nano Tweezer: Charge Stabilization through Sequential Electron Transfer, Angew. Chem. Int. Ed. 2022, 61, e202212474 (1-7). Figure 1

A novel mixed metal orthoborate Ba2ZnTb2(BO3)4: Crystal structure and multicolor emitting properties introduced by Eu3+ doping

Novel mixed metal orthoborate Ba2ZnTb2(BO3)4 was obtained through the high-temperature solid-state reaction at 950 °C. Its crystal structure was determined by single-crystal X-ray diffraction for the first time. The compound crystallizes in the orthorhombic system, Pbca space group, with cell parameters a = 13.4360(1), b = 6.4539(1), c = 25.3262(2) Å, V = 2196.15(4) Å3 and Z = 8. It represents a novel structure type in which ZnO4 tetrahedra and TbO8 polyhedra are interconnected via corner-, edge-, and face-sharing to form 1D [Zn2Tb4O24]n32n− chains. Some B atoms reside in triangular voids of the chains to strengthen the structure, while the others ‘stitch’ the chains together via B–O bonds to create a 3D [Zn2Tb4(BO3)8]n8n− network, with the open channels hosting Ba2+ ions. In addition, polycrystalline samples of Ba2ZnTb2-2xEu2x(BO3)4 (0 ≤ x ≤ 1) were synthesized via solid-state reaction at 780 °C and systematically characterized by powder XRD combined with Rietveld refinements, SEM, IR/Raman, XPS and photoluminescence spectroscopy. As it was revealed, due to the Tb3+ → Eu3+ energy transfer, the emission color of the obtained phosphors can be continuously tuned from green (0.2947, 0.5876) to orange (0.5766, 0.3994) and eventually to red (0.6419, 0.3536) upon the near-UV excitation at 377 nm through changing the Eu3+/Tb3+ ratio. The representative Ba2ZnTb1.998Eu0.002(BO3)4 sample shows a QY of ∼14.84 % (λex = 377 nm), and its emission intensity at 423 K still maintains ∼66 % of that at 303 K. All these observations indicate that, by properly doping activators and selecting the excitation wavelength, this borate phosphor displays multicolor tunable emission that may have potential applications in multicolor lighting and color display.

Halogen‐Mixed 1D CsPbIBr2 Photodetectors for Enhanced Ultraweak Light Detection

AbstractMetal halide perovskites recently have emerged as a promising candidate for photodetection due to their exceptional photoelectric performance. However, the high dark current in these materials has hindered their practical application to imaging. In this study, a novel halogen‐mixed CsPbIBr2 microwire photodetector that has a remarkable reduction of dark current by over 100‐fold (compared to CsPbBr3), along with a substantial increase in photocurrent, which yields a significantly improved on/off ratio of 6.56 × 104, is developed. More importantly, the halogen‐mixed perovskite photodetector exhibits enhanced photodetection performance, including a high responsivity of 133 A W−1 and a remarkable specific detectivity of 4.02 × 1012 Jones even under ultraweak light conditions as low as 4.5 nW cm−2. More specifically, high‐resolution images are successfully obtained under ultraweak light conditions. The combined analysis of experimental results and first‐principles calculation attribute the excellent performance of the CsPbIBr₂ microwire photodetector to a significant reduction in dark current by suppressing ion migration and increasing carrier effective mass, and a remarkable increase in photocurrent resulting from reduced bandgap and enhanced light absorption, as compared to CsPbBr3. This research represents a significant advancement in the development of high‐performance 1D perovskite‐based photodetectors, with promising implications for ultra‐weak light imaging applications.

Effect of different LED light colors on welfare, performance, some behavioral patterns, and blood parameters of Muscovy ducks

BackgroundThe current study was conducted to assess the impact of different LED light colors on welfare indicators in Muscovy ducks. These welfare parameters encompassed growth performance, specific behaviors, tonic immobility (TI), feather score, haematological, and serum biochemical parameters. Eighty-four healthy unsexed Muscovy ducklings aged two weeks were randomly assigned to four groups (3replicates/group; each replicate contains 7 birds) based on different LED light colors. The first group was raised under white light, the second under red light, the third under blue light, and the fourth under yellow light. To assess the impact of various LED light colors on welfare, growth performance indicators (body weight, body weight gain, feed intake, and feed conversion ratio) were measured. Behavioral patterns including feeding, drinking, standing, walking, sitting, feather pecking, and other activities were recorded. Tonic immobility test (TI) and feather condition scoring were conducted at 3, 6, and 10 weeks of age. At the end of the study blood samples were collected for hematological and serum biochemical analyses.ResultsThe results revealed that using blue, yellow, and red colors had no adverse effect on the final body weight of the ducks (P > 0.05). Unlike to red light, blue light significantly reduced feather pecking, TI time and cortisol concentrations and improved the feather condition score (P ≤ 0.05).ConclusionsThe current findings suggest that the application of blue light effectively improves welfare indices and has no detrimental impact on the growth performance of Muscovy ducks thereby positively contributing to their welfare.

Synthesis and photoluminescence of Ba1-xSrxMgSi4O10:Eu2+ phosphors for warm white light-emitting-diodes

Efficient and thermally stable blue-cyan-emitting phosphors are urgently demanded to cover the “cyan gap” for high quality light-emitting-diodes (LEDs) lighting. This work provides a series of blue to cyan color-tunable Ba0.96-xSrxMgSi4O10:0.04Eu2+ phosphors developed via solid-solution method. The phase transformation, photoluminescence, quantum efficiency and thermal stability were investigated in detail. Notably, Sr2+ substitution is effective to red-shift the emission toward cyan emission (from 465 to 480 nm). Simultaneously, the quantum efficiency and thermal stability can be well maintained. Finally, using a 365 nm near-ultraviolet (NUV) LED chip combining with the as-prepared blue-cyan-emitting phosphor, β-SiAlON:Eu2+ green-emitting phosphor and CaAlSiN3:Eu2+ red-emitting phosphor, a warm-white LED device was fabricated with correlated color temperature (CCT) of 4329 K, and color-rendering index (CRI) of 92. These results indicate that the Ba1-xSrxMgSi4O10:Eu2+ blue-cyan-emitting phosphors may have potential applications for high quality NUV-pumped warm-white LED lighting.