scholarly journals Towards Efficient Luminescent Solar Energy Concentrator Using Cuprorivaite Infrared Phosphor (CaCuSi4O10)—Effect of Dispersing Method on Photoluminescence Intensity

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3952
Author(s):  
Piotr Sobik ◽  
Olgierd Jeremiasz ◽  
Paweł Nowak ◽  
Agata Sala ◽  
Bartłomiej Pawłowski ◽  
...  
Keyword(s):  
Near Infrared ◽  
Blue Pigment ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
Near Infrared Reflectance ◽  
Roll Mill ◽  
Bead Mill ◽  
Nir Emission ◽  
Solar Energy Concentrator ◽  
The Relationship

Cuprorivaite, also known as Egyptian blue (EB), CaCuSi4O10, has been utilized as an important blue pigment for thousands of years. It shows a 430–800 nm broad excitation band and an intense 910–920 nm near-infrared (NIR) emission peak at room temperature. The application that motivates the current research is for luminescent solar concentrator (LSC) usage. Current technology for this purpose relies on high near-infrared reflectance. This article addresses the investigation of the relationship between dispersing methods and photoluminescence (PL) intensity. Mechanical grinding methods investigated in the study were: horizontal bead mill, exfoliation and three-roll mill. The initial aim of the study was to verify if the proposed methods do not damage PL. To the surprise of the authors, three-roll mill treatment enhanced PL by nearly 50% without altering the morphology of the powder. An X-ray diffraction study suggested slight alterations in the crystal lattice.

On the Scales Associated with Near-Infrared Reflectance Difference Spectra

1995 ◽  
Vol 49 (6) ◽  
pp. 765-772 ◽  
Author(s):  
M. S. Dhanoa ◽  
S. J. Lister ◽  
R. J. Barnes
Keyword(s):  
Near Infrared ◽  
Scatter Correction ◽  
The Other ◽  
Difference Spectra ◽  
Near Infrared Reflectance ◽  
Standard Normal Variate ◽  
Near Infrared Spectra ◽  
Standard Normal ◽  
Relationship Of ◽  
The Relationship

Scale differences of individual near-infrared spectra are identified when set-independent standard normal variate (SNV) and de-trend (DT) transformations are applied in either SNV followed by DT or DT then SNV order. The relationship of set-dependent multiplicative scatter correction (MSC) to SNV is also referred to. A simple correction factor is proposed to convert derived spectra from one order to the other. It is suggested that the suitable order for the study of changes using difference spectra (when removing baselines) should be DT followed by SNV, which leads to all derived spectra on the scale of mean zero and variance equal to one. If baselines are identical, then SNV scale spectra can be used to calculate differences.

Synthesis, Characterization and Optical Properties of Y6-xSmxMoO12+σ Composite/Compounds Pigments with High Near-Infrared Reflectance

2012 ◽  
Vol 602-604 ◽  
pp. 102-106 ◽  
Author(s):  
Xiao Yu Zhang ◽  
Yu Jun Zhang ◽  
Hong Yu Gong ◽  
Xin Qiao Zhao ◽  
Cui Ling Wang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Solid State Reaction Method ◽  
Inorganic Pigments ◽  
Infrared Reflectance ◽  
X Ray Diffraction ◽  
Near Infrared Reflectance ◽  
X Ray ◽  
Bright Yellow ◽  
Simple Solid State Reaction ◽  
Color Scales

Novel high near-infrared reflecting inorganic pigments Y6-xSmxMoO12+σ (03+ in yttrium molybdate through a simple solid-state reaction method. The composites were characterized using scanning electron microscope, X-ray diffraction, UV-vis-NIR spectrophotometer and CIE 1976 L*a*b* color scales. The substitution of Sm3+ for Y3+ in Y6MoO12 changed the color from bright yellow to dark yellow and most importantly increased near-infrared reflectance in the wavelength range of 700-2500 nm. The chemical stability of the pigments was also evaluated.

scholarly journals Single Er3+, Yb3+: KGd3F10 Nanoparticles for Nanothermometry

2021 ◽  
Vol 9 ◽  
Author(s):  
Karmel de Oliveira Lima ◽  
Luiz Fernando dos Santos ◽  
Rodrigo Galvão ◽  
Antonio Claudio Tedesco ◽  
Leonardo de Souza Menezes ◽  
...  
Keyword(s):  
Intensity Ratio ◽  
Near Infrared ◽  
Continuous Wave ◽  
Thermal Sensitivity ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Thermal Range ◽  
Transmission Electron ◽  
Biological Interest ◽  
Nir Emission

Among several optical non-contact thermometry methods, luminescence thermometry is the most versatile approach. Lanthanide-based luminescence nanothermometers may exploit not only downshifting, but also upconversion (UC) mechanisms. UC-based nanothermometers are interesting for biological applications: they efficiently convert near-infrared radiation to visible light, allowing local temperatures to be determined through spectroscopic investigation. Here, we have synthesized highly crystalline Er3+, Yb3+ co-doped upconverting KGd3F10 nanoparticles (NPs) by the EDTA-assisted hydrothermal method. We characterized the structure and morphology of the obtained NPs by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and dynamic light scattering. Nonlinear spectroscopic studies with the Er3+, Yb3+: KGd3F10 powder showed intense green and red emissions under excitation at 980 and 1,550 nm. Two- and three-photon processes were attributed to the UC mechanisms under excitation at 980 and 1,550 nm. Strong NIR emission centered at 1,530 nm occurred under low 980-nm power densities. Single NPs presented strong green and red emissions under continuous wave excitation at 975.5 nm, so we evaluated their use as primary nanothermometers by employing the Luminescence Intensity Ratio technique. We determined the temperature felt by the dried NPs by integrating the intensity ratio between the thermally coupled 2H11/2→4I15/2 and 4S3/2→4I15/2 levels of Er3+ ions in the colloidal phase and at the single NP level. The best thermal sensitivity of a single Er3+, Yb3+: KGd3F10 NP was 1.17% at the single NP level for the dry state at 300 K, indicating potential application of this material as accurate nanothermometer in the thermal range of biological interest. To the best of our knowledge, this is the first promising thermometry based on single KGd3F10 particles, with potential use as biomarkers in the NIR-II region.

Near Infrared Quantum Cutting for Solar Cells in CeF3:Yb3+ Nanophosphors

2011 ◽  
Vol 366 ◽  
pp. 215-218 ◽  
Author(s):  
Su Wen Li
Keyword(s):  
Solar Cells ◽  
Near Infrared ◽  
Emission Spectra ◽  
Infrared Emission ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Transmission Electron ◽  
Nir Emission ◽  
Quantum Cutting

The CeF3 nanophosphors with Yb3+ concentrations from 0 to 8% had been prepared by hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Their photoluminescence properties including excitation spectra, Uv-visibe and near infrared (NIR) emission spectra and fluorescence dynamics were studied. In the CeF3: Yb3+ nanophosphors an intensity infrared emission originated from Yb3+2F5/2 - 2F7/2 transition at 900-1050 nm matching to the energy of Si band gap of Si-based solar cells was observed under the excitation of 5d level of Ce3+. The lifetime of Ce3+ decreases and the quantum efficiency (QE) increases with increasing Yb3+ concentration.

scholarly journals Thermal consequences of colour and near-infrared reflectance

2017 ◽  
Vol 372 (1724) ◽  
pp. 20160345 ◽  
Author(s):  
Devi Stuart-Fox ◽  
Elizabeth Newton ◽  
Susana Clusella-Trullas
Keyword(s):  
Thermal Effects ◽  
Near Infrared ◽  
Adaptive Variation ◽  
Near Infrared Reflectance ◽  
Animal Coloration ◽  
Research Questions ◽  
Thermoregulatory Function ◽  
Visible Reflectance ◽  
The Relationship ◽  
Perception Function

The importance of colour for temperature regulation in animals remains controversial. Colour can affect an animal's temperature because all else being equal, dark surfaces absorb more solar energy than do light surfaces, and that energy is converted into heat. However, in reality, the relationship between colour and thermoregulation is complex and varied because it depends on environmental conditions and the physical properties, behaviour and physiology of the animal. Furthermore, the thermal effects of colour depend as much on absorptance of near-infrared ((NIR), 700–2500 nm) as visible (300–700 nm) wavelengths of direct sunlight; yet the NIR is very rarely considered or measured. The few available data on NIR reflectance in animals indicate that the visible reflectance is often a poor predictor of NIR reflectance. Adaptive variation in animal coloration (visible reflectance) reflects a compromise between multiple competing functions such as camouflage, signalling and thermoregulation. By contrast, adaptive variation in NIR reflectance should primarily reflect thermoregulatory requirements because animal visual systems are generally insensitive to NIR wavelengths. Here, we assess evidence and identify key research questions regarding the thermoregulatory function of animal coloration, and specifically consider evidence for adaptive variation in NIR reflectance. This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.

Near-Infrared Downconversion in LuPO4: Tm3+, Yb3+ Phosphors

2016 ◽  
Vol 16 (4) ◽  
pp. 3511-3516 ◽  
Author(s):  
Li Li ◽  
Yongjie Wang ◽  
Jun Shen ◽  
Wenxuan Chang ◽  
Tianting Jin ◽  
...  
Keyword(s):  
Tetragonal Phase ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Luminescent Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Crystallinity ◽  
Nir Emission ◽  
Co Precipitation

Tm3+ and Yb3+ codoped LuPO4 phosphors were synthesized by the reverse-strike co-precipitation method. The obtained LuPO4:Tm3+, Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra, and decay lifetime to understand the observed near-infrared downconversion (DC) phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of LuPO4 and exhibit good crystallinity. The experimental results showed that the strong visible emission around 649 nm from Tm3+(1G4 → 3F4) and near-infrared (NIR) emission around 1003 nm from Yb3+(2F5/2 → 2F7/2) of LuPO4:Tm3+, Yb3+ phosphors were observed under 468 nm excitation, respectively. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches 30 mol%. The DC mechanism is also discussed in detail.

Ellipsoid Ultramarine Blue Pigment with High Near-Infrared Reflectance

2021 ◽  
pp. 102267
Author(s):  
Chenglong Lv ◽  
Mei Zu ◽  
Dongjin Xie ◽  
Dongqing Liu ◽  
Haifeng Cheng
Keyword(s):  
Near Infrared ◽  
Blue Pigment ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance ◽  
Ultramarine Blue

Mineralogy of the far-side lunar surface explored by Chang’E-4 with visible and near-infrared reflectance spectra

2021 ◽  
Author(s):  
Gen Ito ◽  
Jessica Flahaut ◽  
Jun Huang
Keyword(s):  
Near Infrared ◽  
Spectral Band ◽  
Reflectance Spectra ◽  
Composition Analysis ◽  
Near Infrared Reflectance ◽  
Spectral Parameters ◽  
Moon Mineralogy Mapper ◽  
Band Depth ◽  
The Relationship ◽  
Initial Classification

<p>The far side of the Moon, which has generally been less frequently targeted by robotic and human missions in the past, has become more available for compositional analyses with measurements made by the Chang’E-4 mission that landed in South Pole-Aitken Basin in 2019. The rover of the mission, Yutu-2, has traversed over 500 m now and acquired more than 100 measurements of visible and near-infrared (VNIR) reflectance spectra. In this study, we analyze the full set of VNIR reflectance spectra collected so far in order to better understand the geology of the Von Karman mare. We compute spectral parameters to quantize major features of spectra and infer mineralogy, e.g., pyroxene composition analysis using the relationship between spectral band depths at 1 µm and 2 µm. Many of Chang’E-4 spectra do not have a detectable spectral band at 2 µm in which case we use spectral parameters for the band at 1 µm to make classifications and infer the presence of other minerals. Pyroxene composition inferred from Chang’E-4 spectra are midway between orthopyroxene and clinopyroxene, showing noticeably unique grouping when compared with 1 µm and 2 µm band depth data available from past studies. For spectra without detectable band at 2 µm, initial classification efforts based solely on spectral parameters of the 1 µm band seem to indicate that at least two distinct groups exist. We are further investigating these preliminary findings, such as through comparisons to data from Moon Mineralogy Mapper, to better understand the mineralogy of the measured materials and the geology of the region explored by Yutu-2 rover. </p>

Relationship between in vitro gas production and near infrared reflectance spectra of gliricidia provenances

1996 ◽  
Vol 1996 ◽  
pp. 226-226
Author(s):  
S.J. Lister ◽  
M.S. Dhanoa ◽  
J.L. Stewart ◽  
M. Gill
Keyword(s):  
Nutritive Value ◽  
Near Infrared ◽  
Gas Production ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance ◽  
In Vitro Gas Production ◽  
The Relationship ◽  
Kinetics Of

The chemical composition of tropical forages is generally more complex than that of temperate forages, yet the need for simple methods to predict nutritive value is greater. Near Infrared Reflectance (NIR) spectra could provide a possible solution. NIR has been used to predict both in vitro and in vivo digestibility (Murray, 1993). Direct calibration with in vivo parameters is ideal, but factors such as different types of forages, animals and management conditions have to be taken into consideration. The gas production technique, which may be considered as an in vitro counterpart of the dacron bag technique, provides information relating to the fermentable fractions and kinetics of a forage and these parameters can be related to the NIR spectra. The aim of this study was to investigate the relationship between NIR spectra and cumulative gas production and derived parameters in tree leaves.

Near-Infrared Quantum Cutting in Yb3+ Doped SrMoO4 Phosphors

2016 ◽  
Vol 16 (4) ◽  
pp. 3494-3499 ◽  
Author(s):  
Xiaobing Luo ◽  
Jun Shen ◽  
He Huang ◽  
Lu Xu ◽  
Zhixiang Wang ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Near Infrared ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Good Crystallinity ◽  
Nir Emission ◽  
Quantum Cutting

Efficient near-infrared (NIR) quantum cutting (QC) has been demonstrated in Yb3+ doped SrMoO4 phosphors synthesized by the high-temperature solid-state reaction method. The obtained SrMoO4:Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra and decay lifetime to understand the observed near-infrared quantum cutting phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of SrMoO4 and exhibit good crystallinity. The experimental results showed that the strong visible molybdate (MoO2−24 emission around 493 nm and near-infrared (NIR) emission around 1000 nm from Yb3+(2F5/2 → 2F7/2) of SrMoO4:Yb3+ phosphors were observed under ultraviolet (290 nm) excitation. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches as high as 10 mol%. The cooperative energy transfer (CET) mechanism was also discussed in detail. The broadband NIR QC phosphors may possibly have potential application in enhancing the conversion efficiency of solar cells.

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