scholarly journals Kirchhoff’s Thermal Radiation from Lithography-Free Black Metals

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 824 ◽  
Author(s):  
Takuhiro Kumagai ◽  
Naoki To ◽  
Armandas Balčytis ◽  
Gediminas Seniutinas ◽  
Saulius Juodkazis ◽  
...  
Keyword(s):  
Optical Properties ◽  
Thermal Radiation ◽  
Structure Design ◽  
Radiation Absorption ◽  
Radiation Emission ◽  
Free Black ◽  
Potential Applications ◽  
Si Films ◽  
Range Characterization ◽  
The Cost

Lithography-free black metals composed of a nano-layered stack of materials are attractive not only due to their optical properties but also by virtue of fabrication simplicity and the cost reduction of devices based on such structures. We demonstrate multi-layer black metal layered structures with engineered electromagnetic absorption in the mid-infrared (MIR) wavelength range. Characterization of thin SiO2 and Si films sandwiched between two Au layers by way of experimental electromagnetic radiation absorption and thermal radiation emission measurements as well as finite difference time domain (FDTD) numerical simulations is presented. Comparison of experimental and simulation data derived optical properties of multi-layer black metals provide guidelines for absorber/emitter structure design and potential applications. In addition, relatively simple lithography-free multi-layer structures are shown to exhibit absorber/emitter performance that is on par with what is reported in the literature for considerably more elaborate nano/micro-scale patterned metasurfaces.

Optical properties of a thin layer of the Vanadium dioxide at the metal state

2015 ◽  
Vol 9 (1) ◽  
pp. 2303-2310
Author(s):  
Abderrahim Benchaib ◽  
Abdesselam Mdaa ◽  
Izeddine Zorkani ◽  
Anouar Jorio
Keyword(s):  
Optical Properties ◽  
Thin Layer ◽  
Vanadium Dioxide ◽  
Ultra Violet ◽  
Index Of Refraction ◽  
Cost Of Energy ◽  
Infra Red ◽  
Metal State ◽  
The Cost ◽  
Reversible Phase

The vanadium dioxide VO₂ currently became very motivating for the nanotechnologies’ researchers. It makes party of the intelligent materials because these optical properties abruptly change semiconductor state with metal at a critical  temperature θ = 68°C. This transition from reversible phase is carried out from a monoclinical structure characterizing its semiconductor state at low temperature towards the metal state of this material which becomes tétragonal rutile for  θ ˃ 68°C ; it is done during a few nanoseconds. Several studies were made on this material in a massive state and a thin layer. We will simulate by Maple the constant optics of a thin layer of VO₂ thickness z = 82 nm for the metal state according to the energy ω of the incidental photons in the energy interval: 0.001242 ≤ ω(ev) ≤ 6, from the infra-red (I.R) to the ultra-violet (U.V) so as to be able to control the various technological nano applications, like the detectors I.R or the U.V,  the intelligent windows to  increase  the energy efficiency in the buildings in order to save the cost of energy consumption by electric air-conditioning and the paintings containing nano crystals of this material. The constant optics, which we will simulate, is: the index of refraction, the reflectivity, the transmittivity, the coefficient of extinction, the dielectric functions ԑ₁ real part and  ԑ₂  imaginary part of the permittivity complexes ԑ of this material and the coefficient absorption. 

A New Type of Cuprous-Cysteamine Sensitizers: Synthesis, Optical Properties and Potential Applications

2021 ◽  
pp. 100435
Author(s):  
Yan Wang ◽  
Noura Dawas Alkhaldi ◽  
Nil Kanatha Pandey ◽  
Lalit Chudal ◽  
Lingyun Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Potential Applications ◽  
New Type

scholarly journals Enhanced luminescence properties of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red phosphors based on composition modulation

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12981-12989
Author(s):  
Biao Shen ◽  
Jianghang Xu ◽  
Qinan Mao ◽  
Jiasong Zhong
Keyword(s):  
Optical Properties ◽  
Quantum Efficiency ◽  
Luminescence Properties ◽  
Composition Modulation ◽  
Red Phosphors ◽  
Potential Applications ◽  
Enhanced Luminescence

A series of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red-emitting phosphors with adjustable optical properties and excellent quantum efficiency was developed for potential applications in warm WLEDs.

scholarly journals Changes in Optical Properties upon Dye–Clay Interaction: Experimental Evaluation and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel
Keyword(s):  
Optical Properties ◽  
Hybrid Materials ◽  
High Performance ◽  
Fluorescent Properties ◽  
Chemical Mechanisms ◽  
Strong Electrostatic Interaction ◽  
Potential Applications ◽  
Photochemical Properties ◽  
Physical And Chemical ◽  
The Relationship

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.

A Nanoscale Adventure with Silicon: Synthesis, Surface Chemistry, and other Surprises

2015 ◽  
Vol 242 ◽  
pp. 383-390
Author(s):  
Md Hosnay Mobarok ◽  
Tapas K. Purkait ◽  
Jonathan G.C. Veinot
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Surface Chemistry ◽  
Research Group ◽  
Size Dependent ◽  
Earth Abundant ◽  
Potential Applications ◽  
Si Quantum Dots

The preparation and surface chemistry Si quantum dots (SiQDs) are currently an intense focus of research because of their size dependent optical properties and many potential applications. SiQDs offer several advantages over other quantum dots; Si is earth abundant, non-toxic and biocompatible. This account briefly highlights recent advancements made by our research group related to the synthesis, functionalization, surface dependent optical properties and applications of SiQDs.

The Light Absorption Properties of Cu2S Nanowire Arrays

2012 ◽  
Vol 528 ◽  
pp. 272-276 ◽  
Author(s):  
Shan Ren ◽  
Li Qiang Li ◽  
Zhu Feng Liu ◽  
Ming Li ◽  
Lan Hong
Keyword(s):  
Optical Properties ◽  
Distribution Density ◽  
Photovoltaic Cell ◽  
Nanowire Arrays ◽  
Band Gaps ◽  
Infrared Light ◽  
Infrared Band ◽  
Absorption Properties ◽  
Potential Applications ◽  
Cu Foil

Cu2S nanowire arrays with different morphologies were prepared by solid-gas reaction between Cu foil and mixture gas of H2S and O2. Their microstructures were observed with XRD, TEM, and the optical properties were measured by DRS, PL and Raman. The results showed that the nanowire were Cu2S single crystal with a thin layer CuxO (x=1, 2) over the surface. The optical properties of the Cu2S nanowire arrays are related to the diameter, length, and distribution density of nanowire arrays. The thinner is the nanowire’s diameter; the bigger is the absorption of the visible light, and the absorbance begun to descend within infrared band. The absorbance of nanowire arrays with bigger diameter to the infrared light was stronger than that with thinner diameter. The photoluminescence spectrum (PL) indicated that band gaps of Cu2S nanowire arrays also changed simultaneously with the nanowire arrays’ structure parameters. The research demonstrated the Cu2S nanowire arrays’ potential applications in the photovoltaic cell and solar-heat harvesting area.

scholarly journals Radical-Scavenging and UV-Radiation Absorption Activities of Aaptamine Derivatives: DFT and TD-DFT Studies

2021 ◽  
Author(s):  
Thi Hoai Nam Doan ◽  
Thi Le Anh Nguyen ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
Duy Quang Dao
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Radical Adduct ◽  
Td Dft ◽  
Potential Applications

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Optimized geometries of C1C3 and theirs intrinsic thermochemical properties such as bond dissociation energy, proton affinity, and ionization potential were calculated at DFT/M05-2X/6-311++G(d,p) level of theory in vacuo and in water. The results show that C1C3 exhibited similar potent antioxidant activities, which are comparable to well-known antioxidants such as Trolox or cembrene. The radical scavenging activity of the antioxidants were then investigated by evaluation the Gibbs free energy (ΔrG0) of the reaction between C1C3 and the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1@C19 while RAF is more dominant with C2 and C3. Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. In addition, all compounds are active in UV-Vis absorption; the excitations of which are determined as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient<br>

scholarly journals Thermal Radiation Absorption in Rectangular-Groove Cavities

1963 ◽  
Vol 30 (2) ◽  
pp. 237-244 ◽  
Author(s):  
E. M. Sparrow ◽  
V. K. Jonsson
Keyword(s):  
Thermal Radiation ◽  
Incident Energy ◽  
Radiation Absorption ◽  
External Radiation ◽  
Energy Distributions ◽  
Surface Conditions ◽  
Incoming Radiation ◽  
Wide Range ◽  
Cavity Opening ◽  
Rectangular Groove

The amount of energy absorbed when a stream of external radiation enters a rectangular-groove cavity has been calculated for a variety of surface conditions, cavity depths, and incident energy distributions. The surfaces of the cavity are either diffuse reflectors or specular reflectors, and a wide range of reflectivity values has been considered. The incoming radiation is either diffusely distributed across the cavity opening or else arrives in a bundle of parallel rays. The results show that for diffuse incoming radiation, a specular cavity absorbs more effectively than does a diffuse cavity. For incoming radiation in a parallel ray bundle, the comparison depends on the angle of inclination of the rays.

Suppression of Crystal Nucleation in Amorphous Si Thin Films by High Energy Ion Irradiation at Intermediate Temperatures

1990 ◽  
Vol 201 ◽  
Author(s):  
James S. Im ◽  
Jung H. Shin ◽  
Harry A. Atwater
Keyword(s):  
Ion Irradiation ◽  
High Energy ◽  
Intermediate Temperature ◽  
Crystal Nucleation ◽  
Potential Applications ◽  
Annealing Cycle ◽  
Amorphous Si ◽  
Si Films ◽  
Device Technology

AbstractIn situ electron microscopy has been used to observe crystal nucleation and growth in amorphous Si films. Results demonstrate that a repeated intermediate temperature ion irradiation/thermal annealing cycle can lead to suppression of nucleation in amorphous regions without inhibition of crystal growth of existing large crystals. Fundamentally, the experimental results indicate that the population of small crystal clusters near the critical cluster size is affected by intermediate temperature ion irradiation. Potential applications of the intermediate temperature irradiation/thermal anneal cycle to lateral solid epitaxy of Si and thin film device technology are discussed.

Compositional Changes in the Infrared Optical Properties of Cr Doped CdZnTe Crystals

2005 ◽  
Vol 864 ◽  
Author(s):  
U. Hömmerich ◽  
A.G. Bluiett ◽  
EiEi Nyein ◽  
S.B. Trivedi ◽  
R.T. Shah
Keyword(s):  
Optical Properties ◽  
Ir Absorption ◽  
Solid State Lasers ◽  
Crystal Field Effect ◽  
Spectral Shifts ◽  
Zn Content ◽  
Potential Applications ◽  
Vertical Bridgman ◽  
Compositional Changes ◽  
Ir Emission

AbstractWe are currently investigating the infrared (IR) optical properties of Cr doped ternary cadmium chalcogenides for potential applications in solid-state lasers and passive optical Qswitches. In this paper, we present compositional changes in the IR optical properties of Cr doped Cd1-xZnxTe single crystals with x=0.05, 0.1, and 0.2. Undoped CdZnTe crystals were grown by vertical Bridgman technique. Cr doping of CdZnTe was achieved through either in-situ doping or through a thermal diffusion process. For comparison, Cr: CdTe and Cr: ZnTe crystals were also prepared. The optical properties of Cr2+ ions were strongly dependent on the host composition and spectral blue shifts were observed with increasing Zn content in Cr: CdZnTe. The IR absorption peak of Cr2+ ions shifted from ∼1910 nm for Cr: CdTe to ∼1815 nm for Cr: Cd0.8Zn0.2Te. Less pronounced blue shifts were observed for the IR emission from Cr: CdZnTe crystals. The spectral shifts can be explained by the decrease in bond-length when going from CdTe to CdZnTe leading to an increased crystal-field effect experienced by Cr2+ ions. A slight broadening of the absorption and emission was also observed in ternary Cr: CdZnTe compounds compared to Cr: CdTe, which suggests that Cr2+ ions were incorporated in multiple lattice sites in CdZnTe. Moreover, the Cr2+ emission dynamics revealed a slightly non-exponential decay behavior for Cr: CdZnTe crystals, whereas the decay time of Cr: CdTe was single-exponential.

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