Search

A recent study showed the potential of the DA Perten 7200 NIR Spectrometer in detecting chlorpyrifos-methyl pesticide residue in rough, brown, and milled rice. However, this instrument is still lab-based and generally suited for point-of-sale testing. To provide a field-deployable version of this technique, an existing light emitting diode (LED)-based instrument that provides discrete NIR wavelength illumination and reflectance spectra over the range of 850–1550 nm was tested. Spectra were collected from rough, brown, and milled rice at different pesticide concentrations and analyzed for quantitative and qualitative measurement using partial least squares regression (PLS) and discriminant analysis (DA). Simulations for two LED-based instruments were also evaluated using corresponding segments of spectra from the DA7200 to represent LED illumination. For the simulation of the existing LED-based instrument (LEDPrototype1) fitted with 850, 910, 940, 970, 1070, 1200, 1300, 1450, and 1550 nm LED wavelengths, resulting R2 ranged from 0.52 to 0.71, and the correct classification was 70.4% to 100%. The simulation of a second LED instrument (LEDPrototype2) fitted with 980, 1050, 1200, 1300, 1450, 1550, 1600, and 1650 nm LED wavelengths showed R2 of 0.59 to 0.82 and correct classifications of 66% to 100%. These LED wavelengths were selected based on the significant wavelength regions from the PLS regression coefficients of DA7200 and the commercial availability of LED wavelengths. Results showed that it is possible to use a multi-spectral LED-based instrument to detect varying levels of chlorpyrifos-methyl pesticide residue in rough, brown, and milled rice. [ABSTRACT FROM AUTHOR]

Environment-friendly indium phosphide (InP)-based quantum dots (QDs) with efficient red-emitting properties are sufficiently needed to satisfy the requirement of burgeoning display and lighting technology. Currently, the syntheses of InP QDs using tris(trimethylsilyl)phosphine as the precursor are highly toxic and expensive. Herein, we successfully introduced gallium (Ga) ions into tris(dimethylamino)phosphine-based red InP cores through thermally-promoted cation exchange, and the obtained Ga-doped InP cores exhibited significantly increased photoluminescence quantum yields (PLQY) of up to 26%. The existence of Ga was directly confirmed by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy, and the functions of Ga were systematically studied. After subsequent coating of Ga-doped InP cores with ZnSeS and ZnS shells, the resulting Ga-InP/ZnSeS/ZnS QDs achieved a high PLQY of 62% with an emission maximum at 640 nm. In contrast, without Ga-doping, the PLQY only attained 36% using the same synthetic approach. This indicated an approximate 1.7-fold increase in PLQY. The enhancement of photoluminescence was related to the Ga3+, as it not only passivated surface defects of InP cores but also reduced core-shell interface stress. The Ga-InP/ZnSeS/ZnS QDs exhibited good stability towards heat treatment and ultraviolet (UV) irradiation. Moreover, the red light-emitting diode (LED) based on Ga-InP/ZnSeS/ZnS QDs performed well in a wide injected current range of 2 to 200 mA, with a maximum power efficiency of 0.68 lm/W. This work showcases Ga-doping through cation exchange as a promising strategy for enhancing the efficiency of InP-based red emitters. [ABSTRACT FROM AUTHOR]

Background: Cognitive function, including moral decision-making abilities, can be impaired by sleep loss. Blue-enriched light interventions have been shown to ameliorate cognitive impairment during night work. This study investigated whether the quality of moral decision-making during simulated night work differed for night work in blue-enriched white light, compared to warm white light. Methods: Using a counterbalanced crossover design, three consecutive night shifts were performed in blue-enriched white light (7000K) and warm white light (2500K) provided by ceiling-mounted LED luminaires (photopic illuminance: ~200lx). At 03:30h on the second shift (i.e. twice) and at daytime (rested), the Defining Issues Test-2, assessing the activation of cognitive schemas depicting different levels of cognitive moral development, was administered. Data from 30 (10 males, average age 23.3±2.9 years) participants were analysed using linear mixed-effects models. Results: Activation of the post-conventional schema (P-score), that is, the most mature moral level, was significantly lower for night work in warm white light (EMM; estimated marginal mean = 44.3, 95% CI = 38.9-49.6; pholm=.007), but not blue-enriched white light (EMM = 47.5, 95% CI = 42.2-52.8), compared to daytime (EMM = 51.2, 95% CI = 45.9-56.5). Also, the P-score was reduced for night work overall (EMM = 45.9, 95% CI = 41.1-50.8; p=.008), that is, irrespective of light condition, compared to daytime. Neither activation of the maintaining norms schema (MN-score), that is, moderately developed moral level, nor activation of the personal interest schema (i.e. the lowest moral level) differed significantly between light conditions. The MN-score was however increased for night work overall (EMM = 26.8, 95% CI = 23.1-30.5; p=.033) compared to daytime (EMM = 23.1, 95% CI = 18.9-27.2). Conclusion: The results indicate that moral decisions during simulated night work in warm white light, but not blue-enriched white light, become less mature and principle-oriented, and more rule-based compared to daytime, hence blue-enriched white light may function as a moderator. Further studies are needed, and the findings should be tentatively considered. Trial registration: ClinicalTrials.gov (ID: NCT03203538) Registered: 26/06/2017; https://clinicaltrials.gov/study/NCT03203538 [ABSTRACT FROM AUTHOR]

Abstract Organic–inorganic hybrid light-emitting devices have garnered significant attention in the last few years due to their potential. These devices integrate the superior electron mobility of inorganic semiconductors with the remarkable optoelectronic characteristics of organic semiconductors. The inquiry focused on analyzing the optical and electrical properties of a light-emitting heterojunction that combines p-type GaN with organic materials (PEDOT, PSS, and PMMA). This heterojunction is an organic–inorganic hybrid. The procedure entailed utilizing a spin-coating technique to apply a layer of either poly(methyl methacrylate) (PMMA) or a mixture of PMMA and poly(3,4ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT: PSS) onto an indium tin oxide (ITO) substrate. Subsequently, different Nd:YAG laser pulses (200, 250, and 300 pulses) were used to administer a GaN inorganic layer onto the prepared organic layer using a pulsed laser deposition approach. Subsequently, the thermal evaporation technique was employed to deposit an aluminum electrode on the top of the organic and inorganic layers, while laser pulses were fine-tuned for optimal performance. The Hall effect investigation verifies the p-type conductivity of the GaN material. The electroluminescence studies confirmed the production of blue light by the GaN-based devices throughout a range of voltage situations, spanning from 45 to 72 V.

Perovskite quantum dots (PQDs) have shown great promise for use in photovoltaic devices, due to their ability to offer advantages such as tunability of visible light and efficient light emission. This study demonstrates the successful utilization of a triazine-based PO-T2T (2,4,6-Tris[3(diphenylphosphenyl)phenyl]-1,3,5-triazine; PO-T2T) as the electron transport layer (ETL) through an all-solution process. To improve the structural and optical characterization of CsPbBr3 and CsPbI3 QDs, three organic solvents, namely chlorobenzene, methyl acetate, and ethyl acetate, were selected to find an effective orthogonal solvent for PO-T2T. The all-solution processed devices incorporating PO-T2T and Methyl acetate (MeOAc) demonstrated impressive external quantum efficiencies of 5.57% for CsPbBr3 and 1.60% for CsPbI3 QDs. Notably, these devices also achieved the highest maximum luminance among all-solution processed PQDs-LEDs, with values of 33334 cd m–2 for CsPbBr3 and 224 cd m–2 for CsPbI3 QDs.

Abstract In this research, we introduce an advanced methodology for the calculation of bulk light sources tailored for free-form surface design, focusing on the principle of energy conservation. This method is especially relevant for the evolving needs of micro-LED packaging, highlighting its potential in this burgeoning field. Our work includes the development of an algorithm for creating freeform-designed chip-scale package (FDCSP) components. These components seamlessly integrate LEDs and lenses, underscoring our commitment to advancing free-form surface design in chip-level packaging. By adhering to the principle of energy conservation, our approach facilitates a meticulous comparison of simulation outcomes with predefined target functions. This enables the iterative correction of discrepancies, employing layering techniques to refine the design until the simulated results closely align with our goals, as demonstrated by an appropriate difference curve. The practical application of these simulations leads to the innovative design of FDCSP devices. Notably, these devices are not just suitable for traditional applications in backlight modules but are explicitly optimized for the emerging sector of micro-LED packaging. Our successful demonstration of these FDCSP devices within backlight modules represents a significant achievement. It underscores the effectiveness of our design strategy and its expansive potential to transform micro-LED packaging solutions. This research not only contributes to the theoretical understanding of energy conservation in lighting design but also paves the way for groundbreaking applications in micro-LED and backlight module technologies.

Perovskite quantum dots (PQDs) have shown great promise for use in photovoltaic devices, due to their ability to offer advantages such as tunability of visible light and efficient light emission. This study demonstrates the successful utilization of a triazine-based PO-T2T (2,4,6-Tris[3(diphenylphosphenyl)phenyl]-1,3,5-triazine; PO-T2T) as the electron transport layer (ETL) through an all-solution process. To improve the structural and optical characterization of CsPbBr 3 and CsPbI 3 QDs, three organic solvents, namely chlorobenzene, methyl acetate, and ethyl acetate, were selected to find an effective orthogonal solvent for PO-T2T. The all-solution processed devices incorporating PO-T2T and Methyl acetate (MeOAc) demonstrated impressive external quantum efficiencies of 5.57% for CsPbBr 3 and 1.60% for CsPbI 3 QDs. Notably, these devices also achieved the highest maximum luminance among all-solution processed PQDs-LEDs, with values of 33334 cd m–2 for CsPbBr 3 and 224 cd m–2 for CsPbI 3 QDs. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid light-emitting devices have garnered significant attention in the last few years due to their potential. These devices integrate the superior electron mobility of inorganic semiconductors with the remarkable optoelectronic characteristics of organic semiconductors. The inquiry focused on analyzing the optical and electrical properties of a light-emitting heterojunction that combines p-type GaN with organic materials (PEDOT, PSS, and PMMA). This heterojunction is an organic–inorganic hybrid. The procedure entailed utilizing a spin-coating technique to apply a layer of either poly(methyl methacrylate) (PMMA) or a mixture of PMMA and poly(3,4ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT: PSS) onto an indium tin oxide (ITO) substrate. Subsequently, different Nd:YAG laser pulses (200, 250, and 300 pulses) were used to administer a GaN inorganic layer onto the prepared organic layer using a pulsed laser deposition approach. Subsequently, the thermal evaporation technique was employed to deposit an aluminum electrode on the top of the organic and inorganic layers, while laser pulses were fine-tuned for optimal performance. The Hall effect investigation verifies the p-type conductivity of the GaN material. The electroluminescence studies confirmed the production of blue light by the GaN-based devices throughout a range of voltage situations, spanning from 45 to 72 V. [ABSTRACT FROM AUTHOR]

In this research, we introduce an advanced methodology for the calculation of bulk light sources tailored for free-form surface design, focusing on the principle of energy conservation. This method is especially relevant for the evolving needs of micro-LED packaging, highlighting its potential in this burgeoning field. Our work includes the development of an algorithm for creating freeform-designed chip-scale package (FDCSP) components. These components seamlessly integrate LEDs and lenses, underscoring our commitment to advancing free-form surface design in chip-level packaging. By adhering to the principle of energy conservation, our approach facilitates a meticulous comparison of simulation outcomes with predefined target functions. This enables the iterative correction of discrepancies, employing layering techniques to refine the design until the simulated results closely align with our goals, as demonstrated by an appropriate difference curve. The practical application of these simulations leads to the innovative design of FDCSP devices. Notably, these devices are not just suitable for traditional applications in backlight modules but are explicitly optimized for the emerging sector of micro-LED packaging. Our successful demonstration of these FDCSP devices within backlight modules represents a significant achievement. It underscores the effectiveness of our design strategy and its expansive potential to transform micro-LED packaging solutions. This research not only contributes to the theoretical understanding of energy conservation in lighting design but also paves the way for groundbreaking applications in micro-LED and backlight module technologies. [ABSTRACT FROM AUTHOR]

Energy reduction is a great challenge in road lighting applications. Replacing high-pressure sodium vapor (HPSV) with light-emitting diodes (LED) is a viable approach to reducing energy consumption. However, a total replacement can incur a significant capital cost. This study aims to investigate the effects on light distribution by replacing HPSV lamps with LED lamps in HPSV luminaires using Light Intensity Distribution (LID) curve measurement and Backlight, Uplight and Glare (BUG) rating evaluation to reduce the adoption costs. While LED lamps have high illumination rates, the structural differences from HPSV lamps can affect the LID curve and original lighting design. Therefore, it is crucial to study photometric dispersion after retrofitting light sources. Both lamps were installed into similar HPSV luminaires to assess photometric performance using goniophotometer measurements. The HPSV lamp outperforms the LED lamp in terms of luminous flux (11.13%) and light intensity (7.69%), whereas the LED lamp outperforms the HPSV lamp in terms of efficacy rating (68.67%) and wattage used (47.61%). The findings indicate that retrofit LED luminaires have an LOR of 46.77% lower than the HPSV luminaires. The light distribution pattern is maintained but reduced to 40 to 50% for the main usable light angles. The reduced performance is caused by the lamp structure, which occupies a large area inside the luminaire housing, obstructing proper light distribution. Although overall energy consumption is reduced, similar illumination levels cannot be maintained. These outcomes can assist authorities and manufacturers with alternative methods of reducing costs while maintaining lighting levels. [ABSTRACT FROM AUTHOR]

Underwater video regulation is an insightful research field that can help engineers with bettering investigation on the lowered condition. Submerged video preparing has been utilized in a many fields, such as submerged infinitesimal location, landscape examining, mine identification, media transmission connections, and self-proficient lowered vehicles. Be that as it may, submerged video experiences solid assimilation, dissipating, shading contortion, and clamor from the manufactured light sources, causing video obscure, cloudiness, and a somewhat blue or greenish tone. In this way, the improvement can be separated into two techniques, submerged video de-preliminaries and underexposed video concealing remaking. Relentless in remote correspondence structures, for instance 3G, 4G, and so on, a coming crisis is endless deftly of the nonattendance of consistently Radio Frequency (RF) resources; this deterrent in moving speed cannot strengthen the improvement notable for high information speed. So the new innovation of Light-Fidelity (Li-Fi) came into picture. This innovation can be contrasted to that of Wi-Fi and offers points of interest like expanded available spectrum efficiency, effectiveness, security, low idleness and a lot higher speed. Communication is accomplished by exchanging light-emitting diode (LED) lights on and off at a speed higher than what is detectable to the human eye. This paper presents the explanation behind underexposed picture corruption and surveys the cutting-edge knowledge calculations like video reduce hazing algorithm. In this calculation, it uses two different de-hazing methods, simple Dark Channel Prior (DCP) and Approximate Dark Channel Prior (ADCP), to reduce haze in a video. [ABSTRACT FROM AUTHOR]

This state-of-the art review is designed to state the competence of fullerene nanostructures in optoelectronic devices. Fullerene molecules own valuable structural, electronic, optical, electrical, and physical properties to be employed in optoelectronics device sector. Especially, modification of fullerene nanostructures and nanocomposite formation led to high performance light emitting diodes, optical sensors, and photovoltaics systems. Combination of conjugated polymers/molecules with fullerene has found to further enhance performance efficacy towards these devices. In nanocomposite form, fullerene molecules have been known to develop conjugation with conducting polymers for better charge, hole, or electron transference leading to device performance assistances. Consequently, conjugated polymers like poly(3-hexylthiophene), poly(3,4-ethylenedioxythiophene), poly(3-hexylthiophene-2,5-diyl), polystyrene sulfonate, polycyclopenta-dithiophene-benzothiadiazole, poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene), 4,4′-bis[(p-trichlorosilylpropylphenyl)phenylamino] biphenyl, etc. reinforced with fullerene have been utilized. Polymers with grafted fullerenes such as [6,6]-phenyl C61-butyric acid methyl ester and [6,6]-phenyl-C61-butyric acid hexyl ester and reinforced fullerene have also been recognized. In addition, non-conducting polymers like poly(methyl methacrylate) nanocomposite with fullerene was exploited. Mostly, fullerene C60 and C70 have been preferred as nanofiller in optoelectronic assemblies. Effectiveness of fullerene nanomaterials has been observed for luminescent light emitting diodes, solar cells (bulk heterojunction/polymer/perovskite), and optical sensors (photo-/organic/bacterial sensing). Nevertheless, fullerene nanocomposite designs need to be comprehensively investigated for better device performance by overcoming underlying working mechanism, fabrication, and performance challenges in related fields.

Numerical simulations of carrier transport in aluminium gallium nitride based ultraviolet light emitting diodes (UV-LED) are performed in order to understand injection efficiency for light sources in the deep ultraviolet. With our simulator, calibrated with experimental data from a 265 nm UV-LED, quantum efficiencies have been analyzed. The maximum internal quantum efficiency (IQE) of 30% consists of the product from radiative recombination efficiency (RRE) of 60% and carrier injection efficiency (CIE) of 50%. It is found that poor hole injection into the active region and a surplus of electrons limit both efficiencies, and leads to significant electron leakage into the p-side. This leakage is bias dependent, and has a minimum at maximum IQE. Further simulations show that distributed polarization doping (DPD) could improve carrier injection efficiency.

This paper extends previous work on liquid-crystal-display-based angle-of-arrival (AoA) estimation, initially performed for only a single light source (LS), by considering scenarios with multiple LSs. First, the system model is revisited to investigate parameters that influence detection of multiple LSs. Next, challenges such as separation of co-located LSs and ambiguities are investigated. It is identified that target separation gets increasingly challenging with decreasing distance between LSs, and AoA estimation developed for a single LS leads to ambiguities in scenarios with multiple LSs. These problems are solved by a novel angular separation algorithm and dedicated intensity measurements. Finally, two new experimental setups are introduced to investigate and model optical diffraction effects, and to verify theoretical derivations by measurement results.

Aluminium Gallium Nitride (AlGaN) based light emitting diodes (LED) are the enabling technology for compact emitters of deep ultraviolet (DUV) radiation and are in high demand for environmental and medical applications. The efficiency of recent DUV LEDs is in the range of a few percent providing some potential for improvement. Apart from the light extraction efficiency the hole injection into the active region presents a major obstacle towards more efficient DUV LEDs. In this work, we investigate the emission spectra of a mixed multi quantum well (MQW) DUV LED to attain details on the active region carrier transport that allow an improvement of the hole injection. Changing the position of the long wavelength marker quantum well yields characteristic emission spectra which have been modelled with a multi scale carrier transport and luminescence simulator. The numerical modelling enables the extraction of opaque carrier transport characteristics in AlGaN such as the hole mobility in the highly doped barriers of the MQW.

Rubens Camargo Siqueira1,2 1Department of Retina, Rubens Siqueira Research Center, São José do Rio Preto, São Paulo, Brazil; 2Postgraduate Department, Faculty of Medicine of São José do Rio Preto (FAMERP), São José do Rio Preto, São Paulo, BrazilCorrespondence: Rubens Camargo Siqueira, Email siqueiraretina@gmail.comAbstract: Photobiomodulation (PBM) is a type of phototherapy that employs light-emitting diodes (LEDs) or low-power lasers to selectively administer specific wavelengths of visible light, ranging from 500 to 1000 nm, including near-infrared (NIR) wavelengths. LEDs are advantageous compared to lasers due to their ability to treat large areas at a lower cost, lack of tissue damage potential in humans, and reduced risk of eye-related accidents. The ophthalmology community has recently taken interest in PBM as a promising novel approach for managing various retinal conditions such as age-related macular degeneration, retinopathy of prematurity, retinitis pigmentosa, diabetic retinopathy, Leber’s hereditary optic neuropathy, amblyopia, methanol-induced retinal damage, and potentially others. This review critically assesses the existing body of research on PBM applications in the retina, focusing on elucidating the underlying mechanisms of action and evaluating the clinical outcomes associated with this therapeutic modality.Keywords: photobiomodulation, near-infrared, light emitting diode, age-related macular degeneration

AbstractBackground Cognitive function, including moral decision-making abilities, can be impaired by sleep loss. Blue-enriched light interventions have been shown to ameliorate cognitive impairment during night work. This study investigated whether the quality of moral decision-making during simulated night work differed for night work in blue-enriched white light, compared to warm white light.Methods Using a counterbalanced crossover design, three consecutive night shifts were performed in blue-enriched white light (7000 K) and warm white light (2500 K) provided by ceiling-mounted LED luminaires (photopic illuminance: ∼200 lx). At 03:30 h on the second shift (i.e. twice) and at daytime (rested), the Defining Issues Test-2, assessing the activation of cognitive schemas depicting different levels of cognitive moral development, was administered. Data from 30 (10 males, average age 23.3 ± 2.9 years) participants were analysed using linear mixed-effects models.Results Activation of the post-conventional schema (P-score), that is, the most mature moral level, was significantly lower for night work in warm white light (EMM; estimated marginal mean = 44.3, 95% CI = 38.9–49.6; pholm=.007), but not blue-enriched white light (EMM = 47.5, 95% CI = 42.2–52.8), compared to daytime (EMM = 51.2, 95% CI = 45.9–56.5). Also, the P-score was reduced for night work overall (EMM = 45.9, 95% CI = 41.1–50.8; p=.008), that is, irrespective of light condition, compared to daytime. Neither activation of the maintaining norms schema (MN-score), that is, moderately developed moral level, nor activation of the personal interest schema (i.e. the lowest moral level) differed significantly between light conditions. The MN-score was however increased for night work overall (EMM = 26.8, 95% CI = 23.1–30.5; p=.033) compared to daytime (EMM = 23.1, 95% CI = 18.9–27.2).Conclusion The results indicate that moral decisions during simulated night work in warm white light, but not blue-enriched white light, become less mature and principle-oriented, and more rule-based compared to daytime, hence blue-enriched white light may function as a moderator. Further studies are needed, and the findings should be tentatively considered.Trial registration: ClinicalTrials.gov (ID: NCT03203538) Registered: 26/06/2017; https://clinicaltrials.gov/study/NCT03203538

The COVID-19 pandemic highlighted public awareness of airborne disease transmission in indoor settings and emphasized the need for reliable air disinfection technologies. This increased awareness will carry in the post-pandemic era along with the ever-emerging SARS-CoV variants, necessitating effective and well-defined protocols, methods, and devices for air disinfection. Ultraviolet (UV)-based air disinfection demonstrated promising results in inactivating viral bioaerosols. However, the reported data diversity on the required UVC doses has hindered determining the best UVC practices and led to confusion among the public and regulators. This article reviews available information on critical parameters influencing the efficacy of a UVC air disinfection system and, consequently, the required dose including the systems components as well as operational and environmental factors. There is a consensus in the literature that the interrelation of humidity and air temperature has a significant impact on the UVC susceptibility, which translate to changing the UVC efficacy of commercialized devices in indoor settings under varying conditions. Sampling and aerosolization techniques reported to have major influence on the result interpretation and it is recommended to use several sampling methods simultaneously to generate comparable and conclusive data. We also considered the safety concerns and the potential safe alternative of UVC, far-UVC. Finally, the gaps in each critical parameter and the future research needs of the field are represented. This paper is the first step to consolidating literature towards developing a standard validation protocol for UVC air disinfection devices which is determined as the one of the research needs.

Light Emitting Diodes (LEDs) is one of the newest ways to light up outdoor areas such as streets, stadiums, airports, military bases, harbors, and high mast towers. The main reason for the high focus is power consumption with better brightness. Even though LEDs have so many benefits, researchers should focus on better managing temperatures as the main reason behind the failure of LEDs is overheating. In this article, modern research trends like using heat pipes filled with nanofluids, ionic winds, spray cooling, use of fins, refrigerants, and oil cooling are focused on and discussed concerning LEDs, solar stills, electric vehicle batteries, and different heat transfer devices to develop a new way to handle the heat from higher-wattage LEDs. There is a research thrust in the field of more than one nanoparticle in the base fluid, and its proportions are not analyzed during LEDs cooling study using a heat pipe. It is necessary to control the heat using a more effective technique. Heat pipe with nanofluid is a more efficient, compact, and cost-effective cooling device o reduce LED failure due to higher heat flux. Hence, it is promising to use nanofluid-filled heat pipes to serve the purpose of the life span enhancement of LEDs. [ABSTRACT FROM AUTHOR]

In consumer electronics, Organic LED (OLED) has become mainstream display technology. Using organic materials, opto-electronics devices have become extensively desirable for various reasons. One of the fundamental properties i.e., flexibility permits to fabricate electronic circuits on flexible substrates to make these devices bendable and stretchable. This paper provides a review on various terms of OLED like fabrication methods, operation of OLED, its categorization, few OTFT driven OLEDs, stability issues of white OLED and various applications of OLED based on sensors, display, and lighting. Different lighting devices like incandescent bulb, tube light, CFL, LED and OLED are compared on the basis of their efficiency and lifetime. The comparison highlights that the LED provides good lifetime, however, for OLED it depends on the organic semiconducting materials responsible for emission. Different layers such as charge injection layers, transport layers and blocking layer to refine the properties of organic LEDs are also studied and compared. Addition to this, a low-cost methodology is also incorporated for the fabrication of flexible devices. [ABSTRACT FROM AUTHOR]

The significant parameters for a high-speed optoelectronic switch were the transient times. In the time domain, there is a time elapsed on the order of microseconds between applying a current pulse and seeing an output. Therefore, the present work aimed to give a closer look on the factors affecting the transient times of the optocoupler switching action, namely; delay (td)-, rise (tr)-, in addition to storage (ts)- and fall (tf)-times. The turn-on time (Ton = td + tr) and turn-off time (Toff = ts + tf) of the optocoupler (type 4N25) were investigated and plotted under the influence of different operating conditions such as: load resistance (RL), forward LED drive current (IF), bias collector voltage (VCC), emitter–base resistance (RBE), and ambient temperature. [ABSTRACT FROM AUTHOR]

Research on road safety is continuously developing with the applications of sensors and technologies. Another area that draws the attention of the developers for road safety are in the road accident response. As the number of riders and cyclists increase, so do the accidents particularly at night where visibility is limited. This study presents a method of integration of inflatable safety vests for riders with light emitting diode LED signaling strips embedded in its front and back, and sensors to send the location of the rider when an accident hap-pens. The LED strips are controlled using a wireless remote switch to make the rider more visible other than that embedded in the motorcycle or bicycle. The airbag will activate once an accident occurs and or the rider is detached from the motorcycle. A force-sensitive resistor (FSR) is used as a triggering device attached to the vest when an accident happens where a global positioning system (GPS) module will send the location and a map to a specific mobile number for response. Three trials were conducted to test the functionality of the LED lights for signaling. The device functioned well, that both the left, right, and standby mode were activated. The functionality of the location tracker is also tested in three different locations. The FSR was triggered and it gave the exact location by sending the coordinates and a link to view it on google maps with an average transmit and receive time of 3 seconds. It is recommended that the prototype be developed using light-weight materials and batteries. [ABSTRACT FROM AUTHOR]

Light‐emitting diode (LED) lights produce a variety of wavelengths that have demonstrable efficacy in therapeutic and aesthetic fields. However, a repetitive treatment regimen is required to produce treatment outcomes, which has created a need for portable LED devices. In this study, we aimed to develop a portable therapeutic LED device and investigate its healing effect on excisional wounds in a rat model. The 35 × 35 mm‐sized LED device was used on a total of 30 rats with full‐thickness wounds that were divided into two groups depending on radiation intensity (11.1 and 22.2 mW/cm2 group). LED irradiation was performed every 24 h for 30 min, over 14 days, in direct contact with the wound. Percentage wound closure was measured by photographic quantification and was assessed histologically using haematoxylin and eosin (H&E) and Masson's Trichrome staining, and immunohistochemistry for Vascular endothelial growth factor (VEGF) and CD31. Percentage wound closure was significantly higher in 22.2 mW/cm2 irradiated wounds than that in the control wounds on days 7 and 10. The area of collagen deposition was remarkably larger in 22.2 mW/cm2 irradiated wounds than that in the control, with more horizontally organized fibres. CD31 immunostaining confirmed a significant increase in the number of microvessels in 22.2 mW/cm2 irradiated wounds than that in the control wounds, although there was no difference in VEGF immunostaining. Our novel portable LED device accelerates wound healing in a rat model, raising the possibility that portable LED devices can combine convenience with accessibility to play an innovative role in wound dressing. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Light plays an important role in the photosynthesis and metabolic process of microalgae. However, how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown. In this study, the influence of different light conditions, including light colors, densities, and light:dark cycles on the cell growth and biochemical composition of Spirulina platensis was symmetrically characterized. Under different colored lights, S. platensis all shows an increase trend within the increased light intensity ranges; however, each showing different optimal light intensities. At the same light intensity, different colored lights show different growth rate of S. platensis following the sequence of red>white>green>yellow>blue. The maximum growth rate and protein accumulation were determined as 21.88 and 5.10 mg/(L·d) when illuminated under red LED. The energy efficiency of different light sources was calculated and ranked as red>white>blue≈green>yellow. Transcriptomic analysis suggests that red light can promote cell growth and protein accumulation by up-regulating genes related to photosynthesis, carbon fixation, and C-N metabolism pathways. This study provides a conducive and efficient way to promote biomass production and protein accumulation of S. platensis by regulating light conditions. [ABSTRACT FROM AUTHOR]

The synthesis of carbon quantum dots using cassava (Manihot esculenta) waste peels by simple hydrothermal method. Carbon quantum dots were studied using PXRD, and HRTEM analysis, signifying an amorphous graphite carbon structure. The carbon quantum dots have two absorption peaks in the UV–vis spectrum, around 272 and 304 nm which lead to the π–π* and n–π* transitions. The produced CQDs exhibit excitation dependent fluorescence characteristics, with a fluorescence quantum yield of 4.664% at an excitation wavelength of 330 nm. The CQDs revealed a white light emitting diode with the Commission Internationale d'Eclairage (CIE) coordinates (0.35, 0.35). The nonlinear optical absorption 0.294×10−4 (cm/W), nonlinear refractive index 1.8138×10−8 (cm2/W), and third-order NLO susceptibility 5.5 × 10−6 (esu) were calculated using Z-Scan analysis. The synthesized CQDs were utilized for their antibacterial activity used S. aureus (23 mm), B. cereus (33 mm), E. coli (43 mm), and P. aeruginosa (30 mm) as harmful microbes. Our results suggest that Manihot esculenta waste peels CQDs have potential for application in NLO devices, optical switching, and pharmaceuticals.

Despite substantial efforts, the maximum external quantum efficiency (EQE) of red, green, and blue quantum dots remains close to 25%, limited by the outcoupling efficiency of specific device optical structures. Further improvements have primarily focused on optimizing light management. In this study, we employed rod‐shaped nanocrystals instead of sphere‐like quantum dots as the light‐emitting layer. The theoretical device outcoupling efficiency significantly increased to nearly 41% due to the intrinsic horizontal dipole alignment within the quantum rod film, nearly doubling the efficiency compared to quantum dot light‐emitting diodes (QDLEDs). As a result, we achieved record‐high EQEs of 14.1% for green quantum rod light‐emitting diodes, with maximum brightness exceeding 150,000 cd/m 2 , respectively. Our research demonstrates the immense potential of QRLEDs for display and lighting applications, paving a new way for the commercialization of nanocrystal particles. [ABSTRACT FROM AUTHOR]

LED (light-emitting diode) drivers with the non-resonant DC-DC converters produce higher current and voltage ripple than the resonant converters. The resonant converter-based LED drivers provide low cost, high efficiency, enhanced soft switching capabilities, and simple construction. Therefore, this research work is motivated to propose a hybrid resonant converter to power the LED. The proposed modified hybrid resonant with valley-fill converter is built by removing the capacitors across the switches and the output diode is replaced with a valley-fill circuit in the conventional hybrid resonant converter. With the valley-fill circuit, the switches and the diode are subjected to reduced stress, reduced flicker, and improved efficiency. The modified Hybrid resonant converter with valley-fill circuit LED driver’s performance parameters are compared with existing resonant converter topologies in terms of component count, current stress, voltage stress across the switch and output diode, LED voltage ripple, current ripple, and efficiency. A 10 W, 24 V laboratory prototype of modified Hybrid resonant converter with valley-fill circuit LED driver is developed, and the simulation results are validated.

Background: Climate change and growing global population are driving forces that shift the agriculture from open fields to environmentally‐controlled confined systems. In such confined systems, plants are adapted to unique light spectra to achieve maximal qualitative and quantitative yields. In the present study, effects of five light spectra on morpho‐physiological and molecular attributes of peppermint were examined. Treatments included a traditional greenhouse considered as the control, a fluorescent light, and four types of light emitting diodes (LED): red, blue, red‐blue (70:30), and white. Leaf samples were collected from plants and analyzed for volatile constituents using a headspace GC–MS. Meanwhile, changes in the expression profile of genes involved in the biosynthesis of menthol were evaluated. Results: Our results showed that maximal yield (wet and dry biomass) was achieved under greenhouse condition and the red‐blue LED. Application of the red‐blue LED resulted in maximal production of beneficial monoterpenes, which indicate superiority to greenhouse environment. A significant change in the gene expression profile was observed among plants grown under different light treatments. The red‐blue LED was associated with a significant up‐regulation of key genes in the menthol biosynthesis (menthol dehydrogenase and pulegone reductase). This phenomenon was consistent with a higher menthol production under the same condition. Conclusion: The application of red‐blue LED was associated with the highest level of yield and menthol production, whereas it resulted in lower concentrations of unfavorable by‐products (isomenthol, cis‐pulegone, and menthofuran). In conclusion, 70:30 red‐blue LED can be satisfactory applied to maximize growth yield and optimize favorable bioactive constituent in peppermint. [ABSTRACT FROM AUTHOR]

All‐inorganic CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs) have great application prospects in many fields due to their excellent photoelectric properties. However, CsPbX3 NCs are extremely sensitive to water, heat, light, and oxygen, which leads to dramatic photoluminescence quenching and seriously restricts their future commercial applications. Herein, a novel, simple one‐step solution strategy for synthesizing high‐quality CsPbBr3 NCs was reported. By the combination of the hot‐injection process with the mesoporous template confinement effect of the KIT‐6 matrix, the space‐confined growth of NCs was precisely achieved. The CsPbBr3 NCs encapsulated by KIT‐6 (CsPbBr3@KIT‐6 composite) exhibited a uniform size, a high photoluminescence quantum yield (PLQY) of up to 82%, and a narrow full width at half‐maximum (FWHM) of 24 nm. Most importantly, CsPbBr3@KIT‐6 powder composites had dramatically enhanced light, thermal and water stability in comparison with colloidal CsPbBr3 NCs due to the dual protection of organic ligands and matrix templates. Ultimately, a white light‐emitting diode (LED) device was successfully fabricated by encapsulating a mixture of green‐emitting CsPbBr3@KIT‐6 composite and red‐emitting K2SiF6:Mn4+ phosphor onto a blue‐emitting InGaN LED chip. A color coordinate of (0.327, 0.337) and a wide color gamut of 128% NTSC well demonstrate their potential applications in lighting and display. [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]

Motivation: Typical surgical microscopes used for fluorescence-based lymph node detection experience limitations such as weight and restricted adjustability of the integrated light emitting diode (LED) and camera. This restricts the capture of detailed images of specific regions within the lesion. Research goal: This study proposes a miniature observation robot design that offers adjustable working distance (WD) and rotational radius, along with zoom-in/zoom-out functionality. Methods: A five-degree-of-freedom manipulator was designed, with the end effector incorporating an LED and concave lens to widen the beam width for comprehensive lesion illumination. Additionally, a long-pass filter was integrated into the camera system to enhance image resolution. Experimental results: Experiments were conducted using a fluorescence-expressing phantom to evaluate the performance of the robot. Results demonstrated a captured image resolution of 9600 × 3240 pixels and a zoom-in/zoom-out capacity of up to 3.68 times. Conclusion: The proposed robot design is cost-effective and highly adjustable, enabling suitability for rapid and accurate detection of fresh lymph nodes during surgeries. The robot's capability to detect small lesions (<1 cm), as validated by phantom tests, holds promise for the detection of minute lymph nodes. [ABSTRACT FROM AUTHOR]

The formation mechanism of Cd–S–Se quantum dots (QDs) with a CdS/CdSe core–shell structure within a silicate glass system was investigated by monitoring the change in the first excitonic absorption peak of CdSe, CdS, and Cd–S–Se QDs as a function of the heat‐treatment (HT) duration. When a silicate glass containing QD formation components for CdSe or CdS single‐phased QDs was heat‐treated, CdSe QDs grew via Ostwald ripening, whereas CdS QDs hardly formed within the given silicate glass matrix. When the glass, including CdO, ZnSe, and ZnS, was utilized for the synthesis of Cd–S–Se QDs within the glass matrix, Cd–S–Se QDs were successfully formed and exhibited similar growth behavior to CdSe QDs during the initial stage of HT. The structural changes in the QD‐embedded glasses during HT were also monitored by Raman spectroscopy and discussed, and a possible formation mechanism of CdSe/CdS core–shell‐structured QDs within silicate glasses is suggested. [ABSTRACT FROM AUTHOR]

As emerging technologies, numerous studies were carried out based on multiple input multiple output (MIMO) visible light communication (VLC) system that includes both experimental and theoretical demonstrations. MIMO-VLC system significantly suffers from performance deficiency. Recently, Orthogonal Frequency division multiplexing is utilized for maintaining transmission rate and spectral efficiency. LED selection process plays a vital role in enhancing efficiency of generalized LED index modulation system with the adoption of MAP detection component that is greatly influenced by correlation among LED. Therefore, this paper designs a novel concept named fuzzy dynamic arithmetic optimization (FDAO) algorithm for the selection of optimal channel capacity. The proposed FDAO algorithm combines the mechanism of fuzzy logic system with the dynamic arithmetic optimization algorithm to select candidates with good channel capacity. FDAO algorithm automatically extracts and removes the candidate influenced by inaccurate active decisions and optimally selects the candidate solution with good channel capacity. Finally, the comparative analysis is carried out for diverse existing approaches with respect to bit error rate (BER) and index error rate (IER). The experimental analysis reveals that the proposed approach exhibited minimum BER and IER than other techniques. [ABSTRACT FROM AUTHOR]

Over the past few decades, wide-bandgap semiconductor materials have been extensively explored for short-wavelength light-emitting diode (LED) owing to their rich technological applications spanning from phototherapy, sensors, and healthcare, to the indoor plantation. However, to date, few papers have reported violet-emitting (< 435 nm) perovskite materials and LEDs. Despite the tunable bandgap property, perovskite researchers are still lagging to achieve efficient violet emitting material. The presence of toxic lead, environment stability, complex synthesis, and achieving a large bandgap emitter have put a constraint on the development of violet perovskite LEDs. To address the abovementioned issues, herein we report a simple water-assisted synthesis of lead-free wide-bandgap perovskite with bright violet emission. No use of other solvent during synthesis makes our process very simple, cost-effective, and eco-friendly. As synthesized Ce doped Cs3MnBr5 shows a visible blind absorption with an effective optical bandgap of 3.12 eV. Introduction of Ce in Cs3MnBr5 lattice demonstrate dual violet emission peaks at 387 and 419 nm. Our synthesized Cs3MnBr5:Ce also shows a good environment stability with narrow full-width half maxima (FWHM). We achieve the violet light with standard chromaticity coordinates of (0.18044, 0.02034) which makes Cs3MnBr5:Ce a promising candidate for stable violet perovskite LEDs. [ABSTRACT FROM AUTHOR]

Wooden breast myopathy and leg weakness are serious problems in the broiler chicken industry. The color and intensity of light in the chicken habitat affect behavior, including walking of chicks. The present study was conducted to determine whether periodic and local light switching induces locomotion and affects wooden breast myopathy and leg weakness in broiler chicks. Thirty five-day-old broiler chicks were assigned to two pens (4.72 m × 0.73 m each). In the control pen, chicks were reared under three white-light emitting diode (LED) lights until they were 42 days old. In the other pen, chicks were reared under a white LED light located in the center, supplemented with blue or red LED lights on either side of the pen. The color of the LED lights changed every 3 h, from blue and red to red and blue. From 21 d of age, all LED lights were changed and only one of the side lights was turned on every 3 h. From 35 d of age, all three white lights were turned on until 42 d of age. Periodic and local color switching and on-off switching significantly induced locomotion in broiler chicks. Wooden breast scores tended to improve with light-switching treatment. The tibia length, diameter, and breaking strength were not significantly affected. This is the first report showing that locomotion may be induced in broiler chicks by periodic and local lighting switching, and may be useful for improving the health status of broiler chicks.

Light quality (spectral arrangement) and quantity (photoperiod and intensity) influence plant growth and metabolism and also interact with several factors including environmental parameters in defining the plant behavior. The Light Emitting Diode (LED) lights are extensively utilized in the cultivation of several plant species, especially horticultural plants due to their lower power consumption and higher luminous efficiency compared to the conventional fluorescent lights. The aim of this review paper is to examine the potential of LED technology as it relates to plant lighting in greenhouses and other horticultural environments. It also desires to give an in-depth study of the advantages of LED lighting on plant development, yield, the production of secondary metabolites, and defense mechanisms. Horticultural lighting might undergo a revolution because LEDs are used in solid-state lighting, which would be a tremendous advancement after decades of research. LEDs may be used in a variety of horticulture lighting applications, such as tissue culture lighting, controlled environment research lighting, supplementary lighting, and photoperiod lighting for greenhouses. The primary impacts of light colors on plant performance are shown by the spectrum effects of LEDs as an independent source of light, together with the diverse sensitivity of many plant species and alternatives. LED light influences performance of enzyme, gene expression, cell wall formation, plant defense and postharvest quality. The spectrum reactions are mediated by the ambient lighting in a greenhouse, which also indicates a strong relationship between the additional supplementary lighting and changing environmental factors. LEDs are growing further to become cost-effective for even large-scale horticulture lighting applications as light output increases and device expenditures decrease.

Purpose: Despite improvements in resin composite structures, color stability remains a challenge, and esthetic problems are the most common factors in renewing restorations. This study aimed to evaluate the effects of two light-curing units on the color stability of three different resin composite materials during a six-month period. Materials Methods: Three different resin composites (Filtek Z550, Filtek Ultimate Flowable, Filtek Bulk Fill Restorative) with an A2 color shade were prepared for each combination of resin composite-curing unit (5x2mm) for a total of 30 specimens. Specimens were cured with either QTH Hilux Ultraplus (700mW/cm2) for 40 seconds or Radii Plus LED Curing Light (1400mW/cm2) for 20 seconds. For standardization of the amount of transmitted energy to the composite, all specimens received 28J/cm2. Color parameters were measured with a colorimeter (Minolta CR-321, Konica Minolta Sensing Pte Ltd, Singapore) after polymerization and at 24 hours, first week, first month, third month, and sixth month. Color changes(∆E) were calculated for the different storage periods. One-factor repeated three-way analysis of variance (ANOVA) was used to examine the changes in ΔE measurements over time for different fillers and devices. Results: Significant differences between composites and periods were observed in the color stability with polymerization either QTH or LED. Independently of the composites, there was no significant difference at the end of six months between QTH and LED units with a fixed energy density. The Filtek Z550 material showed the smallest and the Filtek Ultimate Flowable material showed the highest ∆E values at the end of the six months among the materials used. Conclusion: Clinically acceptable color changes were observed for all the materials at the end of six months.

The smart street-lighting system (SSLS) is a leading candidate in the smart city. By the time of the last 15 cycles, many meaningful improvements have been executed in the SSLS with the impact of the internet of things technologies and universal networking devices. Conventional smart street lighting systems are restricted to wireless sensor networks, mobile devices, and old lighting control systems. This article presents a comprehensive treatment of network designs, namely communication, control, and wireless sensor-based smart street lighting system by deploying based on their existing system architecture, and network topologies including leading with it a host of privileges. In addition, choosing the right lighting class, high-intensity discharge (HID) lights, and retrofitting lighting technologies have all been covered in detail. This paper's objective is to evaluate various control technologies that may support the many applications deployed on networked streetlights. Moreover, issues and recommendations, distinguished in this paper, will pave the route for future smart street lighting systems that promote a reliable and seamless driving experience and are energy-efficient for environmental sustainability. It is far anticipated that LoRa and Sigfox with additional gateways could be the best possible smart street lighting system options as these technologies are facilitated for long distances but with a limited data rate. It is way more suitable for lighting control compared to other protocols to control thousands of streetlights.

A recent study showed the potential of the DA Perten 7200 NIR Spectrometer in detecting chlorpyrifos-methyl pesticide residue in rough, brown, and milled rice. However, this instrument is still lab-based and generally suited for point-of-sale testing. To provide a field-deployable version of this technique, an existing light emitting diode (LED)-based instrument that provides discrete NIR wavelength illumination and reflectance spectra over the range of 850–1550 nm was tested. Spectra were collected from rough, brown, and milled rice at different pesticide concentrations and analyzed for quantitative and qualitative measurement using partial least squares regression (PLS) and discriminant analysis (DA). Simulations for two LED-based instruments were also evaluated using corresponding segments of spectra from the DA7200 to represent LED illumination. For the simulation of the existing LED-based instrument (LEDPrototype1) fitted with 850, 910, 940, 970, 1070, 1200, 1300, 1450, and 1550 nm LED wavelengths, resulting R2 ranged from 0.52 to 0.71, and the correct classification was 70.4% to 100%. The simulation of a second LED instrument (LEDPrototype2) fitted with 980, 1050, 1200, 1300, 1450, 1550, 1600, and 1650 nm LED wavelengths showed R2 of 0.59 to 0.82 and correct classifications of 66% to 100%. These LED wavelengths were selected based on the significant wavelength regions from the PLS regression coefficients of DA7200 and the commercial availability of LED wavelengths. Results showed that it is possible to use a multi-spectral LED-based instrument to detect varying levels of chlorpyrifos-methyl pesticide residue in rough, brown, and milled rice.

Abstract: In this paper, we performed an experimental study of a LED-pumped Nd:YAG laser that works in QCW and Q-switch modes. We examined how the pump pulse duration affects the laser output. The laser rod was a Nd:YAG crystal with a diameter of 7 mm and a length of 95 mm, side-pumped by 30 LED arrays, each with 18 single dies at 810 nm. The maximum output energy at 1064 nm was 10.5 mJ in the QCW mode, with a pump energy of 81 mJ (230 µs pulses at 1 Hz). The optical conversion efficiency and the slope efficiency were 12.5% and 18%, respectively. In the PQS mode, the output energy was 250 µJ, with a pulse width of 190 ns (FWHM), corresponding to a peak power of 1.31 kW. The beam divergence was 0.3 mrad with TEM00 mode. This LED-pumped Q-switched Nd:YAG laser can be used for laser range finder applications.

Abstract Introduction the use of light emitting diodes (LED) in domestic and public vias have increased in the last 20 years. In addition, the LED light has been used as a light source for medical applications. Objective since humans are increasingly exposed to LEDs, there is an urgency to investigate the possible biological effects on tissues caused by this exposure. So, researchers have been focused their investigations in the application of this light in the health field. Material and method in this review, a search in important databases was performed on the biological effects caused after application of different LED light protocols in in vitro and in vivo studies. Result although most published papers have shown positive results, some of them reported negative biological effects of light LEDs technology on humans’ cells/tissues. Conclusion therefore, the comprehension of the biological effects caused by light LEDs will provide a better assessment of the risks involved using this technology.

BackgroundPsoriasis is a chronic skin disease affecting approximately 3.2% of the population. The 308 nm light emitting diode (LED) is a novel, portable, and cost-effective light source, may have potential in the treatment of localized psoriasis patients in a home setting.ObjectiveTo compare the clinical and dermoscopic responses in localized psoriatic patients undergoing localized phototherapy with 308 nm LED light and excimer laser.MethodsTwenty-two patients with mild-to-moderate psoriasis and symmetrical skin lesions were included in this prospective, randomized, left-to-right body trial. The target lesions were randomly treated with either LED light or excimer laser twice a week for 12 weeks. The responses were evaluated by the local psoriasis severity index (LPSI) scores, and dermoscopic features of the target lesions were examined and analyzed.ResultsOut of the 22 included psoriasis patients, 10 successfully completed the 12 weeks study. Both treatment sides showed similar clinical improvement in terms of clinical response, as evidenced by a LPSI 50 rate of 70% on the LED side and 80% on the excimer side, p > 0.05. Furthermore, the dermoscopic features also exhibited comparable improvement.ConclusionThe efficacy and safety of 308 nm LED light therapy are comparable to 308 nm excimer laser therapy. Moreover, given the portability and cost-effectiveness of 308 nm LED light, it holds great promise as a home phototherapy in the treatment of psoriasis.