scholarly journals Plasmonic Hot Electron Induced Layer Dependent Anomalous Fröhlich Interaction in InSe

2021 ◽  
Author(s):  
Mahfujur Rahaman ◽  
Muhammad Aslam ◽  
Lu He ◽  
Teresa Madeira ◽  
Dietrich Zahn
Keyword(s):  
Electrical Transport ◽  
Finite Element Method Simulation ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
Hot Electron ◽  
Phonon Modes ◽  
Electron Doping ◽  
Fundamental Understanding ◽  
Optoelectronic Applications ◽  
Shed Light

Abstract InSe is one of the most promising two-dimensional (2D) materials for electronic and optoelectronic applications because of its favourable bandgap and superior electron mobility compared to other layered semiconductors. However, due to the polar nature of InSe, Fröhlich interaction plays an important role in electrical transport, which becomes more significant in reduced dimensionality. Until now, it is not yet known how the dimensionality influences the strength and nature of the Fröhlich polaronic effect in InSe. Here, we report on layer dependent anomalous Fröhlich interaction in InSe from bulk to monolayer with the aid of plasmonic hot electron doping. When excited near the localized surface plasmon resonance, plasmonic nanostructures produce highly energetic electrons (known as hot electrons), which can be captured by a semiconductor such as InSe at the interface. These electrons then couple to the polar optical phonons via the Fröhlich interaction in InSe. With the aid of the strong plasmonic field, the Fröhlich interaction enabling us to monitor the polar phonons in conventional Raman measurements. We prepared nanostructures with three different metals (Ag, Au, and Al) using nanosphere lithography on InSe to study the hot electron doping effect by means of Raman spectroscopy. A finite element method simulation was used to understand the coupling between the plasmonic nanostructures and InSe. We observed that the intensity of polar LO phonon modes initially increases gradually with decreasing layer number and then drops drastically from 7L to 6L, i.e. at the thickness where the transition from quasi-direct to indirect bandgap occurs at room temperature. Additionally, a gradual decrease of intensity of the polar modes with decreasing layer thickness below this transition point is observed, which is due to the increasing indirect bandgap nature of InSe suggesting reduced Fröhlich coupling. Our results shed light on fundamental understanding of Fröhlich interaction in InSe, which is crucial for electronic and optoelectronic applications of this promising 2D material.

scholarly journals Plasmonic hot electron induced layer dependent anomalous Fröhlich interaction in InSe

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mahfujur Rahaman ◽  
Muhammad Awais Aslam ◽  
Lu He ◽  
Teresa I. Madeira ◽  
Dietrich R. T. Zahn
Keyword(s):  
Electrical Transport ◽  
Room Temperature ◽  
Gradual Decrease ◽  
Hot Electrons ◽  
Great Promise ◽  
Hot Electron ◽  
Optical Phonons ◽  
Phonon Modes ◽  
Reduced Dimensionality ◽  
Layer Number

AbstractDespite the great promise of InSe for electronic and optoelectronic applications, Fröhlich interaction plays an important role in electrical transport due to the polar nature of it, which can become more significant in reduced dimensionality. Here, we report on how the dimensionality influences the strength and nature of the Fröhlich polaronic effect in InSe with the aid of plasmonic hot electrons injection. Polar optical phonons couple to hot electrons via the Fröhlich interaction in InSe and enable us to monitor them in conventional Raman measurements. We observed that the intensity of these phonon modes initially increases gradually with decreasing layer number and then drops drastically from 7 L to 6 L (transition from quasi-direct to indirect bandgap at room temperature). Additionally, a gradual decrease of intensity of the polar modes with further decreasing layer number is observed due to the increasing indirect bandgap nature of InSe suggesting reduced Fröhlich coupling below this thickness.

Boosting the Electrochemistry of Li2O2 in Lithium−Oxygen Batteries by Plasmon-induced Hot-Electron Injection

2021 ◽  
Author(s):  
Weixue Yang ◽  
Fei Li ◽  
Huali Liu ◽  
Zhen Li ◽  
Jiaqi Zhao ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Localized Surface Plasmon ◽  
Hot Electron ◽  
Au Nps ◽  
Hot Electron Injection ◽  
Lithium Oxygen Batteries

A photo-assisted Li−Oxygen (Li−O2) battery with Au/SnO2 (ASO) hybrid nanotubes as cathode and photocatalyst has been prepared. The localized surface plasmon resonance (LSPR) excitation of gold nanoparticles (Au NPs) can...

scholarly journals Real-time synthesis and detection of plasmonic metal (Au, Ag) nanoparticles under monochromatic X-ray nano-tomography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Amardeep Bharti ◽  
Keun Hwa Chae ◽  
Navdeep Goyal
Keyword(s):  
Particle Size ◽  
Real Time ◽  
Reduction Process ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
X Rays ◽  
X Ray ◽  
The Real ◽  
Size And Shape

AbstractPlasmonic nanostructures are of immense interest of research due to its widespread applications in microelectronics, photonics, and biotechnology, because of its size and shape-dependent localized surface plasmon resonance response. The great efforts have been constructed by physicists, chemists, and material scientists to deliver optimized reaction protocol to tailor the size and shape of nanostructures. Real-time characterization emerges out as a versatile tool in perspective to the optimization of synthesis parameters. Moreover, in the past decades, radiation-induced reduction of metallic-salt to nanoparticles dominates over the conventional direct chemical reduction process which overcomes the production of secondary products and yields ultra-high quality and pure nanostructures. Here we show, the real-time/in-situ synthesis and detection of plasmonic (Au andAg) nanoparticles using single synchrotron monochromatic 6.7 keV X-rays based Nano-Tomography beamline. The real-time X-ray nano-tomography of plasmonic nanostructures has been first-time successfully achieved at such a low-energy that would be leading to the possibility of these experiments at laboratory-based sources. In-situ optical imaging confirms the radiolysis of water molecule resulting in the production of $$e_{aq}^-,\,OH^\bullet ,$$ e aq - , O H ∙ , and $$O_2^-$$ O 2 - under X-ray irradiation. The obtained particle-size and size-distribution by X-ray tomography are in good agreement to TEM results. The effect of different chemical environment media on the particle-size has also been studied. This work provides the protocol to precisely control the size of nanostructures and to synthesize the ultrahigh-purity grade monodisperse nanoparticles that would definitely enhance the phase-contrast in cancer bio-imaging and plasmonic photovoltaic application.

scholarly journals Quantum plasmonics: from jellium models to ab initio calculations

Nanophotonics ◽  
2016 ◽  
Vol 5 (3) ◽  
pp. 409-426 ◽  
Author(s):  
Alejandro Varas ◽  
Pablo García-González ◽  
Johannes Feist ◽  
F.J. García-Vidal ◽  
Angel Rubio
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Plasmonic Nanostructures ◽  
Functional Theory ◽  
Fundamental Understanding ◽  
Invaluable Tool ◽  
Classical Models ◽  
Light Matter Interaction ◽  
Experimental Findings ◽  
The Impact

AbstractLight-matter interaction in plasmonic nanostructures is often treated within the realm of classical optics. However, recent experimental findings show the need to go beyond the classical models to explain and predict the plasmonic response at the nanoscale. A prototypical system is a nanoparticle dimer, extensively studied using both classical and quantum prescriptions. However, only very recently, fully ab initio time-dependent density functional theory (TDDFT) calculations of the optical response of these dimers have been carried out. Here, we review the recent work on the impact of the atomic structure on the optical properties of such systems. We show that TDDFT can be an invaluable tool to simulate the time evolution of plasmonic modes, providing fundamental understanding into the underlying microscopical mechanisms.

scholarly journals Localized Surface Plasmons Enhanced Light Transmission into c-Silicon Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Y. Premkumar Singh ◽  
Amit Jain ◽  
Avinashi Kapoor
Keyword(s):  
Solar Cells ◽  
Metallic Nanoparticles ◽  
Large Scale ◽  
Light Transmission ◽  
Low Cost ◽  
Incident Light ◽  
Solar Spectrum ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
Al Nanoparticles

The paper investigates the light incoupling into c-Si solar cells due to the excitation of localized surface plasmon resonances in periodic metallic nanoparticles by finite-difference time-domain (FDTD) technique. A significant enhancement of AM1.5G solar radiation transmission has been demonstrated by depositing nanoparticles of various metals on the upper surface of a semi-infinite Si substrate. Plasmonic nanostructures located close to the cell surface can scatter incident light efficiently into the cell. Al nanoparticles were found to be superior to Ag, Cu, and Au nanoparticles due to the improved transmission of light over almost the entire solar spectrum and, thus, can be a potential low-cost plasmonic metal for large-scale implementation of solar cells.

scholarly journals Beyond the State of the Art: Novel Approaches for Thermal and Electrical Transport in Nanoscale Devices

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 752 ◽  
Author(s):  
Robert Biele ◽  
Roberto D’Agosta
Keyword(s):  
Electrical Transport ◽  
State Of The Art ◽  
Biological Effects ◽  
The State ◽  
Nanoscale Devices ◽  
Natural Processes ◽  
Physical Chemical ◽  
Novel Approaches ◽  
Shed Light ◽  
Spin Momentum

Almost any interaction between two physical entities can be described through the transfer of either charge, spin, momentum, or energy. Therefore, any theory able to describe these transport phenomena can shed light on a variety of physical, chemical, and biological effects, enriching our understanding of complex, yet fundamental, natural processes, e.g., catalysis or photosynthesis. In this review, we will discuss the standard workhorses for transport in nanoscale devices, namely Boltzmann’s equation and Landauer’s approach. We will emphasize their strengths, but also analyze their limits, proposing theories and models useful to go beyond the state of the art in the investigation of transport in nanoscale devices.

scholarly journals Highly Sensitive and Selective Nanogap-Enhanced SERS Sensing Platform

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 619 ◽  
Author(s):  
ChaeWon Mun ◽  
Vo Thi Nhat Linh ◽  
Jung-Dae Kwon ◽  
Ho Sang Jung ◽  
Dong-Ho Kim ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Near Field ◽  
Polymer Surface ◽  
Molecular Size ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
Sensing Platform ◽  
Highly Sensitive ◽  
Sers Sensing

This paper reports a highly sensitive and selective surface-enhanced Raman spectroscopy (SERS) sensing platform. We used a simple fabrication method to generate plasmonic hotspots through a direct maskless plasma etching of a polymer surface and the surface tension-driven assembly of high aspect ratio Ag/polymer nanopillars. These collapsed plasmonic nanopillars produced an enhanced near-field interaction via coupled localized surface plasmon resonance. The high density of the small nanogaps yielded a high plasmonic detection performance, with an average SERS enhancement factor of 1.5 × 107. More importantly, we demonstrated that the encapsulation of plasmonic nanostructures within nanofiltration membranes allowed the selective filtration of small molecules based on the degree of membrane swelling in organic solvents and molecular size. Nanofiltration membrane-encapsulated SERS substrates do not require pretreatments. Therefore, they provide a simple and fast detection of toxic molecules using portable Raman spectroscopy.

Piezotronics boosted plasmonic localization and hot electron injection of coralline-like Ag/BaTiO3 nanoarrays for photocatalytic application

2021 ◽  
Author(s):  
Yongming Fu ◽  
Zeqian Ren ◽  
Lixia Guo ◽  
Xiu Li ◽  
Yuqing Li ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Coupling Effect ◽  
Electron Injection ◽  
Localized Surface Plasmon ◽  
Hot Electron ◽  
Hot Electron Injection ◽  
Photocatalytic Application

Metal-semiconductor piezo-photocatalysts are generally investigated due to their high photocatalytic performances by coupling effect of piezotronics and localized surface plasmon resonance (LSPR). However, the mechanism is still indistinct, even the...

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