Highly efficient and thermally stable Cr3+-activated silicate phosphors for broadband near-infrared LED applications

Chemical Engineering Journal, Journal Year: 2019, Volume and Issue: 383, P. 123108 - 123108

Published: Oct. 9, 2019

Language: Английский

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Understanding near infrared spectroscopy and its application to skeletal muscle research

Journal of Applied Physiology, Journal Year: 2019, Volume and Issue: 126(5), P. 1360 - 1376

Published: March 7, 2019

Near infrared spectroscopy (NIRS) is a powerful noninvasive tool with which to study the matching of oxygen delivery utilization and number new publications utilizing this technique has increased exponentially in last 20 yr. By measuring state oxygenation primary heme compounds skeletal muscle (hemoglobin myoglobin), greater understanding underlying control mechanisms that couple perfusive diffusive oxidative metabolism can be gained from laboratory athletic field intensive care unit or emergency room. However, NIRS been complicated by diversity instrumentation, inherent limitations some these technologies, associated terminology, general lack standardization protocols. This Cores Reproducibility Physiology (CORP) will describe basic but important detail most common methodologies NIRS, their strengths limitations, discuss potential confounding factors affect quality reproducibility data. Recommendations are provided reduce variability errors data collection, analysis, interpretation. The goal CORP provide readers methodology, best practices so as improve research muscle.

Language: Английский

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Near-Infrared Spectroscopy in Bio-Applications

Molecules, Journal Year: 2020, Volume and Issue: 25(12), P. 2948 - 2948

Published: June 26, 2020

Near-infrared (NIR) spectroscopy occupies a specific spot across the field of bioscience and related disciplines. Its characteristics application potential differs from infrared (IR) or Raman spectroscopy. This vibrational technique elucidates molecular information examined sample by measuring absorption bands resulting overtones combination excitations. Recent decades brought significant progress in instrumentation (e.g., miniaturized spectrometers) spectral analysis methods image processing analysis, quantum chemical calculation NIR spectra), which made notable impact on its applicability. review aims to present as matured technique, yet with great for further advances several directions throughout broadly understood bio-applications. practical value is critically assessed compared competing techniques. Attention given link bio-application fundamental principal features spectra.

Language: Английский

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Muscle Oximetry in Sports Science: A Systematic Review

Sports Medicine, Journal Year: 2017, Volume and Issue: 48(3), P. 597 - 616

Published: Nov. 25, 2017

Language: Английский

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Efficient Broadband Near‐Infrared Emission in the GaTaO₄:Cr³⁺ Phosphor

Advanced Optical Materials, Journal Year: 2021, Volume and Issue: 10(2)

Published: Nov. 1, 2021

Abstract Efficient broadband near‐infrared (NIR) emitting materials with an emission peak centered above 830 nm are crucial for smart NIR spectroscopy‐based technologies. However, the development of these remains a significant challenge. Herein, series design rules rooted in computational methods and empirical crystal‐chemical analysis is applied to identify new Cr 3+ ‐substituted phosphor. The compound GaTaO 4 :Cr emerged from this study based on material's high structural rigidity, suitable electronic environment, relatively weak electron–phonon coupling. Irradiating phosphor 460 blue light generates (λ em,max = 840 nm) covering 700–1100 region electromagnetic spectrum full width at half maximum 140 nm. phase has internal quantum yield 91% excellent thermal stability, maintaining 85% room temperature intensity 100 °C. Fabricating phosphor‐converted light‐emitting diode device shows that intense (178 mW 500 mA) photoelectric efficiency 6%. This work not only provides material potential next‐generation high‐power applications but also highlights set capable developing highly efficient long‐wavelength materials.

Language: Английский

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Efficient and Tunable Luminescence in Ga_2–xIn_xO₃:Cr³⁺ for Near-Infrared Imaging

ACS Applied Materials & Interfaces, Journal Year: 2021, Volume and Issue: 13(27), P. 31835 - 31842

Published: June 29, 2021

Broadband near-infrared (NIR) emitting materials are in great demand as next-generation smart NIR light sources. In this work, a Cr3+-substituted phosphor capable of efficiently converting visible to is developed through the solid solution, Ga2–xInxO3:Cr3+ (0 ≤ x 0.5). The compounds were prepared using high-temperature solid-state synthesis, and crystal electronic structure, morphology, site preference, photoluminescence properties studied. results demonstrate high quantum yield (88%) impressive absorption efficiency (50%) when = 0.4. emission tunable across wide range (713–820 nm) depending on value x. Moreover, fabricating prototype phosphor-converted light-emitting diode (LED) device 450 nm LED [(Ga1.57Cr0.03)In0.4]O3 showed an output power that reached 40.4 mW with photoelectric conversion 25% driven by current 60 mA, while resulting was able identify damaged produce undetectable light. These outstanding potential for imaging applications.

Language: Английский

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Performance comparison of the MOXY and PortaMon near-infrared spectroscopy muscle oximeters at rest and during exercise

Journal of Biomedical Optics, Journal Year: 2018, Volume and Issue: 23(01), P. 1 - 1

Published: Jan. 24, 2018

The purpose of the study was to compare muscle oxygenation as measured by two portable, wireless near-infrared spectroscopy (NIRS) devices under resting and dynamic conditions. A recently developed low-cost NIRS device (MOXY) compared against an established PortaMon system that makes use spatially resolved algorithm. influence increasing external pressure on tissue oxygen saturation index (TSI) indicated both are stable between 2 20 mmHg. However, above this pressure, MOXY reports declining TSI values. Analysis adipose thickness (ATT) shows a significant, nonlinear difference at rest. report similar (%) values low ATT (<7 mm) (PortaMon minus is +1.1±2.8%) with major subsequent change occurring 7 10 mm; >10 mm remains constant (−14.7±2.8%). most likely explanation for small source–detector separation (2.5 cm) in resulting lower penetration into subjects higher ATT. Interday test–retest reliability evaluated five separate occasions, reporting coefficient variation (1.8% 2.5% versus 5.7% 6.2%). In studies male ATT, decreases were strongly correlated during isometric exercise, arterial occlusion, incremental arm crank exercise. greater range, particularly ischemia induced contraction or occlusion (Δ74.3% Δ43.7%; hyperemia MAX—occlusion MIN). This subject group produce physiologically credible measures rest absolute obtained exercise generally not comparable unless corrected physiological calibration following occlusion.

Language: Английский

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Near-infrared spectroscopy-derived muscle oxygen saturation on a 0% to 100% scale: reliability and validity of the Moxy Monitor

Journal of Biomedical Optics, Journal Year: 2019, Volume and Issue: 24(11), P. 1 - 1

Published: Nov. 18, 2019

Near-infrared spectroscopy (NIRS) to monitor muscle oxygen saturation (SmO₂) is rapidly expanding into applied sports settings. However, the technology limited due its inability convey quantifiable values. A test battery assess reliability and validity of a 0% 100% scale modeled by commercially available NIRS device was established. This applies commonly used technique, arterial occlusion method (AOM) repeatability, reproducibility, face validity. total 22 participants completed scrutinize provided device. All underwent repeated AOM tests in passive active conditions. The SmO₂ minimum maximum values were obtained from subsequent analysis. Repeatability reproducibility tested for equivalency Bland–Altman plots generated. Face assessed testing against an a priori defined threshold mixed venous blood during response. exhibits appropriately functional that reliable terms repeatability reproducibility. Under conditions design, considered valid application sports.

Language: Английский

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Accessing High-Power Near-Infrared Spectroscopy Using Cr³⁺-Substituted Metal Phosphate Phosphors

Chemistry of Materials, Journal Year: 2021, Volume and Issue: 34(1), P. 337 - 344

Published: Dec. 30, 2021

Near-infrared (NIR) phosphor-converted light-emitting diode (pc-LED) technology has attracted considerable interest as a next-generation light source for emerging NIR spectroscopic applications. However, discovering efficient broadband phosphors necessary to access the desired long-wavelength (λem ≥ 800 nm) energy window remains challenge. Here, new phosphate phosphor, KGaP2O7:Cr3+, emerged from fundamental study of AMP2O7 (A = Li, Na, K; M Al, Ga, Sc, In) family. This material combines all requisite properties generation photons, including limited defect formation, minimal electron–phonon coupling, subtle octahedral site distortion, and well-separated transition metal substitution sites. Photoluminescence spectroscopy indicates that this emits 700 1100 nm (λmax 815 with full width at half-maximum (fwhm) 127 or 1874 cm–1. Exciting blue LED reveals quantum yield 74.4% an absorption efficiency 44.8%, resulting in excellent external high 33.3% as-prepared sample. A prototype pc-LED device generated output power 473.8 mW photoelectric conversion (10.7% under 500 mA), demonstrating potential applying phosphor LED-based spectroscopy.

Language: Английский

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Producing Tunable Broadband Near-Infrared Emission through Co-Substitution in (Ga_1–xMg_x)(Ga_1–xGe_x)O₃:Cr³⁺

ACS Applied Materials & Interfaces, Journal Year: 2022, Volume and Issue: 14(45), P. 51157 - 51164

Published: Nov. 7, 2022

Broadband near-infrared (NIR) phosphors are in high demand for creating "smart" NIR phosphor-converted light-emitting diode (pc-LED) sources. In this work, a series of Cr3+-substituted NIR-emitting materials with highly efficient, broad, tunable emission spectra achieved by modifying the simple oxide Ga2O3 using [Mg2+-Ge4+] and [Ga3+-Ga3+] co-unit substitution. The results show that peak can be shifted from 726 to 830 nm while maintaining constant excitation blue light region, enabling extensive application. optical properties stem changes Cr3+ crystal field environment upon Intriguingly, temperature-dependent photoluminescence position shows virtually no change co-substituted materials. This abnormal phenomenon is found comprehensive embodiment weakening (red-shift) as temperature increases reduced local structure distortion (blue-shift) increasing temperature. quantum yield, emission, net-zero shift function make phosphor class optimal device incorporation. As result, their performance was studied coating on 450 emitting LED chip. fabricated demonstrates an excellent output power photoelectric conversion efficiency. study provides tunable, broadband spectroscopy applications contributes basic foundation Cr3+-activated phosphors.

Language: Английский

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