scholarly journals Robust Conformal Perfect Absorber Involving Lossy Ultrathin Film

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 57
Author(s):  
Lei Zhang ◽  
Kun Wang ◽  
Hui Chen ◽  
Yanpeng Zhang

Perfect absorbers have been extensively investigated due to their significant value in solar cell, photodetection, and stealth technologies. Various subwavelength structures have been proposed to improve the absorption performances, such as high absorptance, broad band, and wide absorption angle. However, excellent performances usually put forward higher requirements on structural designs, such as varying the geometry sizes or shapes to fit different center wavelengths, which inevitably increases the fabrication burden. Here, a planar sandwich structure involving a layer of highly lossy material is proposed to achieve a robust perfect absorption with 95% absorptance ranging from the visible to near infrared range. Such an excellent absorption performance is also polarization-independent and applicable to a wide incident angle. Furthermore, the proposed design can also be applied to conformal surfaces with a 90% fluctuation over a steep surface. We believe that the proposed perfect absorber with distinguished performances can find wide application.

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 488 ◽  
Author(s):  
Pinghui Wu ◽  
Congfen Zhang ◽  
Yijun Tang ◽  
Bin Liu ◽  
Li Lv

A simple metamaterial absorber is proposed to achieve near-perfect absorption in visible and near-infrared wavelengths. The absorber is composed of metal-dielectric-metal (MIM) three-layer structure. The materials of these three-layer structures are Au, SiO2, and Au. The top metal structure of the absorber is composed of hollow three-dimensional metal rings regularly arranged periodically. The results show that the high absorption efficiency at a specific wavelength is mainly due to the resonance of the Fabry–Perot effect (FP) in the intermediate layer of the dielectric medium, resulting in the resonance light being trapped in the middle layer, thus improving the absorption efficiency. The almost perfect multiband absorption, which is independent of polarization angle and insensitivity of incident angle, lends the absorber great application prospects for filtering and optoelectronics.


Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1038 ◽  
Author(s):  
Huixuan Gao ◽  
Wei Peng ◽  
Shuwen Chu ◽  
Wenli Cui ◽  
Zhi Liu ◽  
...  

The spectral range of solar radiation observed on the earth is approximately 295 to 2500 nm. How to widen the absorption band of the plasmonic absorber in this range has become a hot issue in recent years. In this paper, we propose a highly applicable refractory perfect absorber with an elliptical titanium nanodisk array based on a silica–titanium–silica–titanium four-layer structure. Through theoretical design and numerical demonstration, the interaction of surface plasmon resonance with the Fabry–Perot cavity resonance results in high absorption characteristics. Our investigations illustrate that it can achieve ultra-broadband absorption above 90% from a visible 550-nm wavelength to a near-infrared 2200-nm wavelength continuously. In particular, a continuous 712-nm broadband perfect absorption of up to 99% is achieved from wavelengths from 1013 to 1725 nm. The air mass 1.5 solar simulation from a finite-difference time domain demonstrates that this absorber can provide an average absorption rate of 93.26% from wavelengths of 295 to 2500 nm, which can absorb solar radiation efficiently on the earth. Because of the high melting point of Ti material and the symmetrical structure of this device, this perfect absorber has excellent thermal stability, polarization independence, and large incident-angle insensitivity. Hence, it can be used for solar cells, thermal emitters, and infrared detection with further investigation.


2020 ◽  
Vol 142 ◽  
pp. 109439
Author(s):  
Lu Ju ◽  
Ke-Da Gu ◽  
Yu-Jie Liu ◽  
Lei Xia ◽  
Jiong-Ju Hao ◽  
...  

2014 ◽  
Vol 105 (4) ◽  
pp. 041903 ◽  
Author(s):  
Hiroaki Matsui ◽  
Wasanthamala Badalawa ◽  
Takayuki Hasebe ◽  
Shinya Furuta ◽  
Wataru Nomura ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Dianjun Hu ◽  
Xin Liu ◽  
Ziyu Liu ◽  
Xiaoying Li ◽  
Feng Tian ◽  
...  

As a kind of promising material for a Faraday isolator used in the visible and near infrared range, Dy2O3 transparent ceramics were prepared by vacuum sintering from the nano-powders synthesized by the liquid precipitation method using ammonium hydrogen carbonate as precipitant with no sintering aids. The synthesized precursor was calcinated at 950 °C–1150 °C for 4 h in air. The influences of the calcination temperature on the morphologies and phase composition of Dy2O3 powders were characterized. It is found that the Dy2O3 powder calcinated at 1000 °C for 4 h is superior for the fabrication of Dy2O3 ceramics. The Dy2O3 transparent ceramic sample prepared by vacuum sintering at 1850 °C for 10 h, and subsequently with air annealing at 1400 °C for 10 h, from the 1000 °C-calcined Dy2O3 powders, presents the best optical quality. The values of in-line transmittance of the optimal ceramic specimen with the thickness of 1.0 mm are 75.3% at 2000 nm and 67.9% at 633 nm. The Verdet constant of Dy2O3 ceramics was measured to be −325.3 ± 1.9 rad/(T·m) at 633 nm, about 2.4 times larger than that of TGG (Tb3Ga5O12) single crystals.


2017 ◽  
Author(s):  
K. Max Zhang ◽  
Bo Yang ◽  
Geng Chen ◽  
Jiajun Gu ◽  
James Schwab ◽  
...  

Abstract. DC, also referred to as Delta-C, measures enhanced light absorption of particulate matter (PM) samples at the near-ultraviolet (UV) range relative to the near-infrared range, which has been proposed previously as a woodsmoke marker due to the presence of enhanced UV light absorbing materials from wood combustion. In this paper, we further evaluated the applications and limitations of using DC as both a qualitative and semi-quantitative woodsmoke marker via joint continuous measurements of PM2.5 (by nephelometer pDR-1500) and light-absorptive PM (by 2-wavelength and 7-wavelength Aethalometer®) in three Northeastern U.S. cities/towns including Rutland, VT, Saranac Lake, NY and Ithaca, NY. We compared the pDR-1500 against a FEM PM2.5 sampler (BAM 1020), and identified a close agreement between the two instruments in a woodsmoke-dominated ambient environment. The analysis of seasonal and diurnal trends of DC, BC (880 nm) and PM2.5 concentrations supports the use of DC as an adequate qualitative marker. The strong linear relationships between PM2.5 and DC in both woodsmoke-dominated ambient and plume environments suggest that DC can reasonably serve as a semi-quantitative woodsmoke marker. We proposed a DC-based indicator for woodsmoke emission, which was then shown to exhibit relatively strong linear relationship with heating demand. While we observed reproducible PM2.5-DC relationships in similar woodsmoke-dominated ambient environments, those relationships differ significantly with different environments, and among individual woodsmoke sources. DC correlated much more closely with PM2.5 than EcoChem PAS2000-reported PAH in woodsmoke-dominated ambient environments. Our analysis also indicates the potential for PM2.5-DC relationships to be utilized to distinguish different combustion and operating conditions of woodsmoke sources, and that DC-Heating demand relationships could be adopted to estimate woodsmoke emissions. However, future studies are needed to elucidate those relationships.


2019 ◽  
Vol 85 (3) ◽  
pp. 20-26
Author(s):  
Viktoria Sabov ◽  
Мaria Potorij ◽  
Iwan Kityk ◽  
Mykhailo Filep ◽  
Marian Sabov

Complex chalcogenides display semiconductor properties. In particular, heavy metal compounds that are formed in the Tl2Se-Sb2Se3 system are good thermoelectric materials. At the same time TlSbP2Se6 compound belongs to the family of hexaseleno-hypodiphosphates, which representatives have a number of interesting properties (optoelectric, non-linear, etc.) in the near infrared range. The combination of these properties in one material causes some scientific and practical interest, therefore our research was aimed to study the nature of the interaction between TlSbP2Se6 and the thermally stable phases of the Tl2Se-Sb2Se3 system in order to find new promising candidate for applications in electronic devices. The alloys were prepared from corresponding binary, ternary compounds and quaternary TlSbP2Se6 by a direct one-temperature method in evacuated quartz ampoules at temperatures above the melting point of the initial and final products. The initial compounds were synthesized by the reaction of their high purity component elements in stoichiometric proportion. According to the results of the research, it was found that cross-sections based on TlSbP2Se6 and the thermally stable compounds of the Tl2Se-Sb2Se3 section are quasibinary: Sb2Se3–TlSbP2Se6 and TlSbSe2–TlSbP2Se6. Tl9SbSe6 – TlSbP2Se6 and Tl2Se - TlSbP2Se6 systems are not quasibinary, instead quasibinary sections Tl2Se-Tl4P2Se6 and Tl9SbSe6-Tl4P2Se6 which crossing their. The phase equilibrium in Sb2Se3 – TlSbP2Se6 and TlSbSe2 – TlSbP2Se6 systems were studied by common differential thermal analysis (DTA), X-ray powder diffraction (XRD) and microstructure analysis. The eutectic interactions are observed in both systems. The invariant points coordinates are: 77 mol.% TlSbP2Se6, 709 K (system Sb2Se3 – TlSbP2Se6) and 45 mol.% TISbSe2, 680 K (system TlSbSe2 – TlSbP2Se6). Significant boundary solid solutions are formed on the basis of the quaternary compound. Their region extends up to 10 mol% in the system Sb2Se3 – TlSbP2Se6 and to about 18 mol.% in the system TlSbSe2 –TlSbP2Se6 at annealing temperature (573 К). Near the Sb2Se3 and TlSbSe2, the solubility limits do not exceed several mol.%.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xuehan Liu ◽  
Keyang Li ◽  
Zhao Meng ◽  
Zhun Zhang ◽  
Zhongchao Wei

A subwavelength metamaterial perfect absorber (MPA) in optical communication band was proposed and tested using the finite-difference time-domain method. The absorber is periodic and comprises a top layer of diamond silicon surrounded by L-shaped silicon and a gold layer on the substrate. It can achieve dual-band perfect absorption, and one of the peaks is in the optical communication band. By changing the gap (g) between two adjacent pieces of L-shaped silicon, and the thickness (h) of the silicon layer, the resonance wavelength of absorption peak can be tuned. When the incident electromagnetic wave entered the absorber, the metamaterial absorber could almost completely consume the incident electromagnetic waves, thereby achieving more than 99% perfect absorption. The absorption peak reaches 99.986% at 1310 nm and 99.421% at 1550 nm. Moreover, the MPA exposed to different ambient refraction indexes can be applied as plasma sensors, and can achieve multi-channel absorption with high figure of merit (FOM*) value and refractive index (RI) sensitivity. The FOM* values at 1310 nm and 1550 nm are 6615 and 168, respectively, and both resonance peaks have highly RI sensitivity. The results confirm that the MPA is a dual-band, polarization-independent, wide-angle absorber and insensitive to incident angle. Thence it can be applied in the fields of optical communication, used as a light-wave filter and plasma sensor, and so on.


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