scholarly journals Flexible Broadband Metamaterial Perfect Absorber Based on Graphene-Conductive Inks

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 440
Author(s):  
Le Van Long ◽  
Nguyen Sy Khiem ◽  
Bui Son Tung ◽  
Nguyen Thanh Tung ◽  
Trinh Thi Giang ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Optical Filters ◽  
Wide Frequency Range ◽  
Absorption Feature ◽  
Perfect Absorber ◽  
Frequency Range ◽  
Absorption Mechanism ◽  
Polarization Insensitive ◽  
Metamaterial Perfect Absorber ◽  
High Absorption

In this work, we proposed a flexible broadband metamaterial perfect absorber (FBMPA) by exploiting a pasted conductive-graphene ink on a polyimide substrate. For the flat FBMPA, an absorption over 90% was found to cover a wide frequency range (from 7.88 to 18.01 GHz). The high-absorption feature was polarization-insensitive and regarded as stable with respect to the oblique incidence up to 30 degrees of electromagnetic wave. The high absorption was maintained well even when the absorber was wrapped. That is, the FBMPA was attached to cylindrical surfaces (with the varying radius from 4 to 50 cm). For both flat and curved states, the absorption mechanism was explained by the perfect impedance matching and the dielectric loss of the proposed absorber. Our work provides the groundwork for the commercialization of future meta-devices such as sensors, optical filters/switchers, photodetectors, and energy converters.

scholarly journals Ultrathin perfect absorber based on integrated metamaterial

2020 ◽  
Vol 58 (5) ◽  
pp. 571
Author(s):  
TRAN TIEN LAM ◽  
DINH THI NGA ◽  
DINH VAN THIEN ◽  
NGUYEN SY KHIEM ◽  
BUI XUAN KHUYEN ◽  
...  
Keyword(s):  
Power Loss ◽  
Magnetic Energy ◽  
Impedance Matching ◽  
Perfect Absorber ◽  
Absorption Mechanism ◽  
Compact Structure ◽  
Matching Effect ◽  
Embedded Capacitors ◽  
Operating Wavelength ◽  
Metamaterial Perfect Absorber

We improved common metamaterial perfect absorber (MPA) by integrating four embedded inductors or replacing four embedded capacitors in the same compact structure. The obtained results confirmed that the lumped-capacitors MPA maintains an extreme thickness t = λ/940, where λ is operating wavelength at 106.3 MHz. Besides, by replacing these capacitors by inductors in the initial designed-MPA structure, we obtained an effective thickness of t = λ/53 at 1.9 GHz. Furthermore, we explained the absorption mechanism in terms of the magnetic energy and power loss distributions related to the impedance-matching effect.

scholarly journals Multiband Polarization Insensitive and Tunable Terahertz Metamaterial Perfect Absorber Based on The Heterogeneous Structure of Graphene

2021 ◽  
Author(s):  
Amirhossein Norouzi Razani ◽  
Pejman Rezaei
Keyword(s):  
Fermi Level ◽  
Electric Fields ◽  
Incident Angle ◽  
Heterogeneous Structure ◽  
Perfect Absorber ◽  
Absorption Mechanism ◽  
Central Disk ◽  
Polarization Insensitive ◽  
Metamaterial Perfect Absorber ◽  
Multi Band

Abstract In this paper, we present and investigate a multi-band metamaterial perfect absorber (MPA) based on the heterogeneous structure of graphene with Cu and SiO 2 substrates. The top layer of structure consist of one graphene disk at the center and four graphene solid triangle with semicircular cuts on them that surround the central disk. This heterogeneous structure causes us to achieve 97.06%, 94.71%, 99.7% and 99.5% perfect absorptions peaks at 28239.7 nm, 31048.9 nm, 50898.6 nm and 70689.1 nm, respectively. The absorption mechanism based on electric fields has been investigated. We can shift the wavelength of absorption peaks to our required wavelength by changing the Fermi level (µc) of graphene. Two absorption peaks of this absorber remain unchanged in different incident angle. In addition, very important point about this structure is that it is not sensitive to polarization and this feature makes the proposed absorber very suitable for applications such as imaging, filtering, sensing and detecting applications.

Highly efficient, polarization insensitive terahertz metamaterial perfect absorber and imaging

2012 ◽  
Author(s):  
David. S. Wilbert ◽  
Mohammad P. Hokmabadi ◽  
William Baughman ◽  
Patrick Kung ◽  
Seongsin M. Kim
Keyword(s):  
Perfect Absorber ◽  
Highly Efficient ◽  
Polarization Insensitive ◽  
Metamaterial Perfect Absorber

scholarly journals Design and Fabrication of a Triple-Band Terahertz Metamaterial Absorber

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1110
Author(s):  
Jinfeng Wang ◽  
Tingting Lang ◽  
Zhi Hong ◽  
Meiyu Xiao ◽  
Jing Yu
Keyword(s):  
Optical Communication ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Absorption Mechanism ◽  
Symmetric Configuration ◽  
Electric And Magnetic Fields ◽  
Polarization Insensitive ◽  
Band Absorption ◽  
High Absorption ◽  
Triple Band

We presented and manufactured a triple-band terahertz (THz) metamaterial absorber with three concentric square ring metallic resonators, a polyethylene terephthalate (PET) layer, and a metallic substrate. The simulation results demonstrate that the absorptivity of 99.5%, 86.4%, and 98.4% can be achieved at resonant frequency of 0.337, 0.496, and 0.718 THz, respectively. The experimental results show three distinct absorption peaks at 0.366, 0.512, and 0.751 THz, which is mostly agreement with the simulation. We analyzed the absorption mechanism from the distribution of electric and magnetic fields. The sensitivity of the three peaks of this triple-band absorber to the surrounding is 72, 103.5, 139.5 GHz/RIU, respectively. In addition, the absorber is polarization insensitive because of the symmetric configuration. The absorber can simultaneously exhibit high absorption effect at incident angles up to 60° for transverse electric (TE) polarization and 70° for transverse magnetic (TM) polarization. This presented terahertz metamaterial absorber with a triple-band absorption and easy fabrication can find important applications in biological sensing, THz imaging, filter and optical communication.

scholarly journals Ultrathin Dual-band Metamaterial Absorber

2021 ◽  
Author(s):  
Huan Liu ◽  
Rui Wang ◽  
Junyao Wang ◽  
Tianhong Lang ◽  
Bowen Cui
Keyword(s):  
Simple Structure ◽  
Structural Parameters ◽  
Metamaterial Absorber ◽  
Ring Resonators ◽  
Dual Band ◽  
Absorption Mechanism ◽  
Split Ring ◽  
Absorption Frequency ◽  
Polarization Insensitive ◽  
High Absorption

Abstract In this paper, an ultrathin dual-band metamaterial absorber (MMA) is designed. Its top layer consists of two nested split-ring resonators. The calculation result demonstrates that there are two distinct absorption peaks, which are 9.258GHz and 21.336GHz, with absorption rate of 99.78% and 96.91%. It also show polarization-insensitive for normal incident and its thickness is only 1.96% of the wavelength of its lowest absorption frequency. Moreover, we explore the MMA’s absorption mechanism and analyze the influence of main structural parameters on the MMA’s absorption characteristics. The proposed MMA has simple structure and high absorption, it can be applied in electromagnetic stealth, bolometers, sensor and other fields.

scholarly journals Evidence of Negative Capacitance and Capacitance Modulation by Light and Mechanical Stimuli in Pt/ZnO/Pt Schottky Junctions

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2253
Author(s):  
Raoul Joly ◽  
Stéphanie Girod ◽  
Noureddine Adjeroud ◽  
Patrick Grysan ◽  
Jérôme Polesel-Maris
Keyword(s):  
Impedance Matching ◽  
Mechanical Strain ◽  
Atomic Layer ◽  
Wide Frequency Range ◽  
Interface Trap ◽  
Negative Capacitance ◽  
Mechanical Stimuli ◽  
Trap States ◽  
Frequency Range ◽  
Schottky Junctions

We report on the evidence of negative capacitance values in a system consisting of metal-semiconductor-metal (MSM) structures, with Schottky junctions made of zinc oxide thin films deposited by Atomic Layer Deposition (ALD) on top of platinum interdigitated electrodes (IDE). The MSM structures were studied over a wide frequency range, between 20 Hz and 1 MHz. Light and mechanical strain applied to the device modulate positive or negative capacitance and conductance characteristics by tuning the flow of electrons involved in the conduction mechanisms. A complete study was carried out by measuring the capacitance and conductance characteristics under the influence of both dark and light conditions, over an extended range of applied bias voltage and frequency. An impact-loss process linked to the injection of hot electrons at the interface trap states of the metal-semiconductor junction is proposed to be at the origin of the apparition of the negative capacitance values. These negative values are preceded by a local increase of the capacitance associated with the accumulation of trapped electrons at the interface trap states. Thus, we propose a simple device where the capacitance values can be modulated over a wide frequency range via the action of light and strain, while using cleanroom-compatible materials for fabrication. These results open up new perspectives and applications for the miniaturization of highly sensitive and low power consumption environmental sensors, as well as for broadband impedance matching in radio frequency applications.

Sign in / Sign up

Export Citation Format

Share Document