Abstract The plasmon-induced transparency (PIT), which is destructive interference between the superradiation mode and subradiation mode, studied in patterned graphene-based terahertz metasurface composed of graphene ribbons strips. As results finite-difference time-domain (FDTD) simulation coupled-mode theory (CMT) fitting, PIT can be dynamically modulated by dual-mode. left (right) transmission dip mainly tailored gate voltage applied to (stripes), respectively, meaning a dual-mode...

Abstract We have investigated the electronic structure and carrier mobility of four types phosphorous monolayer sheet (α-P, β-P,γ-P δ-P) using density functional theory combined with Boltzmann transport method relaxation time approximation. It is shown that α-P, β-P γ-P are indirect gap semiconductors, while δ-P a direct one. All sheets ultrahigh show anisotropy in-plane. The highest value ~3 × 10 5 cm 2 V −1 s , which comparable to graphene. Because huge difference between hole electron...

We propose a novel simple patterned monolayer graphene metamaterial structure based on tunable terahertz plasmon-induced transparency (PIT). Destructive interference in this causes pronounced PIT phenomenon, and the response can be dynamically controlled by voltage since existence of continuous bands structural design. The theoretical transmission is calculated coupled mode theory (CMT), results are highly consistent with simulation curve. After that, influence mobility absorption...

Dual plasmon-induced transparency (PIT) and absorption (PIA) are simultaneously achieved in an integrated metamaterial composed of single layer graphene. Electric field distribution coupled mode theory (CMT) used to demonstrate the physical mechanism dual PIT PIA, theoretical result CMT is highly consistent with finite-difference time-domain (FDTD) method simulation result. Further research shows that both PIA phenomenon can be effectively modulated by Fermi level, carrier mobility graphene...

Ultra-high sensitivity sensor has significant application for micro-nano optical devices in terahertz. Here, we propose a simple graphene metasurface, which can achieve obvious plasmon-induced transparency (PIT) phenomenon. We find that PIT, reflectivity, and absorbance be effectively tuned by the Fermi level. Moreover, finite-different time-domain (FDTD) numerical results are well agreement with coupled mode theory (CMT) results. Interestingly, an ultra-high performance based on tunable PIT...

Blue phosphorus is a new graphene-like material which has already been proven thermostable in theory, and the synthesis of it on experiment can also be expected. Here, we have investigated electronic structures carrier mobilities armchair zigzag monolayer blue nanoribbons (PNRs) nanotubes (PNTs) using density functional theory combined with Boltzmann transport method relaxation time approximation. It found that both PNRs PNTs are indirect-gap semiconductors considerable energy gap. The...

A graphene plasmonic structure consists of three layers mingled with a silicon-air grating is proposed. We theoretically predict and numerically simulate the plasmon-induced transparency effect in this system at terahertz wavelengths, dual peaks can be successfully tuned by virtually shifting desired Fermi energy on layers. investigate surface plasmon dispersion relation means analytic calculations, we achieve numerical solution propagation constant got relation. suitable theoretical model...

Abstract We first report a simple nanoplasmonic sensor for both universal and slow-light sensing in Fano resonance-based waveguide system. A theoretical model based on the coupling of resonant modes is provided inside physics mechanism, which supported by numerical FDTD results. The revealed evolution property shows that asymmetric factor p plays an important role adjusting FOM maximum ~4800 obtained when = 1. Finally, such also investigated. It found contradiction between width with (SWS)...

Abstract A terahertz multifunction modulator composed of upper-layer double graphene ribbons and lower-layer a strip, which can generate Fano resonance produced by hybrid between broad mode narrow mode, is proposed to realize electro-optical switch filtering function. The electric field distribution, theory, quantum level theory are all employed explain the resonance, whose transmission spectra fitted coupled theory. In comparison other graphene-based modulators, amplitude modulation degree...

We report the sensing characteristic based on plasmon induced transparency in nanocavity-coupled metal-dielectric-metal waveguide analytically and numerically. A simple model for nature is first presented by coupled mode theory. show that coupling strength resonance detuning play important roles optimizing performance detection limit of sensor, an interesting double-peak also obtained such plasmonic sensor. In addition, specific refractive index width dielectric environment discovered...

We propose an expanded coupled mode theory to analyze sensing performance in a plasmonic slot waveguide side-coupled with multimode stub resonator. It is confirmed by the finite-difference time-domain simulations. Through adjusting parameters, we can realize figure of merit (FOM) ∼59,010, and sensitivity S reach 75.7. Compared systems recent Letters, our proposed structure has advantages easy fabrication, compactness, sensitivity, high FOM. The model findings provide guidance for fundamental...

Abstract We propose a nanoplasmonic waveguide side-coupled with bright-dark-dark resonators in our paper. A multi-oscillator theory derived from the typical two-oscillator model, is established to describe spectral features as well slow-light effects structures and confirmed by finite-difference time domain (FDTD). That plasmon induced transparency (PIT) turns double PIT spectra observed this structure. At same time, multi-switching obvious bands based on are also discovered proposed What’s...

A novel monolayer graphene structure whose unit cell possesses two rectangular defects is proposed. very obvious dual plasmon-induced transparency (PIT) effect can be successfully achieved by the destructive interference in terahertz region. The PIT easily tuned changing Fermi energy of graphene. Since our exists a continuous form, we simply apply bias voltage to achieve tuning performance compared those structures with discontinuous patterns. We have deduced expression theoretical...

The modification of the electronic structure bilayer MoS2 by an external electric field can have potential applications in optoelectronics and valleytronics. Nevertheless, underlying physical mechanism is not clearly understood, especially effects van der Waals interaction. In this study, spin orbit-coupled has been investigated using first-principle density functional theory. We find that interaction as well interlayer distance significant on band structure. When increases from 0.614 nm to...

Black phosphorus (BP) is a novel plasmonic materials at the infrared and terahertz regions. We have theoretically investigated anisotropic of in-plane monolayer BP in terms conductivity. designed periodic structure for special shape achieved an obvious plasmon-induced transparency phenomenon. The results finite difference time domain simulation coupled mode theory are consistent good agreement. It found that bandwidth phenomenon window can be effectively adjusted by changing structure. Since...

Abstract A dual-frequency on–off modulator with considerable modulation depth (MD) and relatively low insertion loss (IL) is performed patterned monolayer graphene metamaterial. Destructive interference in this structure gives rise to the dual plasmon-induced transparency (DPIT) phenomenon. The coupled mode theory, confirmed by simulated values, comprehensively introduced expound physical mechanism of DPIT effect. In addition, influences Fermi level on transmission spectrum carrier mobility...

A novel graphene-based grating-coupled metamaterial structure is proposed, and the optical response of this can be obviously controlled by Fermi level, which theoretically regulated electric field an applied voltage. The upper graphene monolayer intensely excited with aid periodic grating thus it considered a bright mode. Meanwhile, lower cannot directly excited, but could indirectly activated help plasmonic polaritons resulting from light-graphene interaction resonance lead to destructive...

Excellent and wide-band absorption is of great benefit for lots applications such as photoelectric conversions, photonics commutations well photovoltaic cells. Here, a simple MXene/Au-based metamaterial, consisting thick layer Ti3C2Tx Au-Nanorod, studied through finite-difference time-domain (FDTD) method realization tunable strong in the visible near infrared. The results show that enhanced with AMAX = 0.99 can be realized proposed metamaterial. Moreover, effectively tuned by structural...

Abstract Due to the superior properties of graphene and application potential surface plasmons, research plasmons has become a hot direction. Based on graphene, this paper done some researches plasma induced transparency, absorption, slow light effect. The main work results are as follows: we have designed graphene-based metamaterial structure that can realize dual transparency (PIT) specific is formed by periodic arrangement bands (as bright mode) band edge microchips mode). We use...

CuO-Ni(OH)

Abstract Prolonging energetic hot electrons lifetimes and surface activity in the reactive site can overcome slow kinetics unfavorable thermodynamics of photo‐activated gas sensors. However, bulk recombination limit simultaneous optimization both thermodynamics. Here tandem electric fields are deployed at (111)/(100)Au‐CeO 2 to ensure a sufficient driving force for carrier transfer elucidate mechanism relationship between charge transport gas‐sensing performance. The asymmetric structure...