scholarly journals Bandgap Control in Two-Dimensional Semiconductors via Coherent Doping of Plasmonic Hot Electrons

2020 ◽  
Author(s):  
Yu-Hui Chen ◽  
Ronnie Tamming ◽  
Kai Chen ◽  
Zhepeng Zhang ◽  
Fengjiang Liu ◽  
...  
Keyword(s):  
Charge Carriers ◽  
Hot Electrons ◽  
Two Dimensional ◽  
Effective Measure ◽  
Plasmonic Crystal ◽  
Optical Responses ◽  
2D Semiconductors ◽  
Coherent Coupling ◽  
Plasmon Resonances ◽  
First Time

Abstract Bandgap control is of central importance for semiconductor Technologies. The traditional means of control is to dope the lattice chemically, electrically or optically with charge carriers. Here, we demonstrate for the first time a widely tunable bandgap (renormalisation up to 650 meV at room-temperature) in two-dimensional (2D) semiconductors by coherently doping the lattice with plasmonic hot electrons. In particular, we integrate tungsten-disulfide (WS_2) monolayers into a self-assembled plasmonic crystal, which enables coherent coupling between semiconductor excitons and plasmon resonances. Accompanying this process, the plasmon-induced hot electrons can repeatedly fill the WS2 conduction band, leading to population inversion and a significant reconstruction in band structures and exciton relaxations. Our findings provide an innovative and effective measure to engineer optical responses of 2D semiconductors, allowing a great flexibility in design and optimisation of photonic and optoelectronic devices.

scholarly journals Bandgap control in two-dimensional semiconductors via coherent doping of plasmonic hot electrons

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu-Hui Chen ◽  
Ronnie R. Tamming ◽  
Kai Chen ◽  
Zhepeng Zhang ◽  
Fengjiang Liu ◽  
...  
Keyword(s):  
Charge Carriers ◽  
Hot Electrons ◽  
Two Dimensional ◽  
Central Importance ◽  
Effective Measure ◽  
Plasmonic Crystal ◽  
Optical Responses ◽  
2D Semiconductors ◽  
Coherent Coupling ◽  
Plasmon Resonances

AbstractBandgap control is of central importance for semiconductor technologies. The traditional means of control is to dope the lattice chemically, electrically or optically with charge carriers. Here, we demonstrate a widely tunable bandgap (renormalisation up to 550 meV at room-temperature) in two-dimensional (2D) semiconductors by coherently doping the lattice with plasmonic hot electrons. In particular, we integrate tungsten-disulfide (WS2) monolayers into a self-assembled plasmonic crystal, which enables coherent coupling between semiconductor excitons and plasmon resonances. Accompanying this process, the plasmon-induced hot electrons can repeatedly fill the WS2 conduction band, leading to population inversion and a significant reconstruction in band structures and exciton relaxations. Our findings provide an effective measure to engineer optical responses of 2D semiconductors, allowing flexibilities in design and optimisation of photonic and optoelectronic devices.

scholarly journals Plasmonic magneto-optical nested 2D nanostructures: tailoring responses through effective refractive index

2018 ◽  
Vol 190 ◽  
pp. 03011
Author(s):  
Alexey Shaimanov ◽  
Alexander Baryshev
Keyword(s):  
Refractive Index ◽  
Effective Refractive Index ◽  
Structural Parameters ◽  
Optical Response ◽  
Two Dimensional ◽  
Dimensional Lattice ◽  
Optical Responses ◽  
Plasmon Resonances

Spectra of a nested square two-dimensional lattice of metal nanospheres encased in a magneto-optical host were studied. We show that the magneto-optical response of the nanostructures considerably increases due to the plasmon resonances. Moreover, the optical and magneto-optical responses can be strongly altered with a negligible change in structural parameters.

Direct imaging of charge transfer

1996 ◽  
Vol 54 ◽  
pp. 680-681
Author(s):  
Yimei Zhu ◽  
J. Tafto
Keyword(s):  
Charge Transfer ◽  
Electron Diffraction ◽  
Scattering Amplitude ◽  
High Temperature Superconductors ◽  
Charge Carriers ◽  
Image Charge ◽  
Net Charge ◽  
Long Time ◽  
Electron Holes ◽  
First Time

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.

scholarly journals Influence of a Standing Wave Flow-Field on the Dynamics of a Spray Diffusion Flame

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
J. Barry Greenberg ◽  
David Katoshevski
Keyword(s):  
Liquid Phase ◽  
Flow Field ◽  
Standing Wave ◽  
Diffusion Flame ◽  
Stokes Number ◽  
Flame Height ◽  
Wave Flow ◽  
Two Dimensional ◽  
Governing Equations ◽  
First Time

A theoretical investigation of the influence of a standing wave flow-field on the dynamics of a laminar two-dimensional spray diffusion flame is presented for the first time. The mathematical analysis permits mild slip between the droplets and their host surroundings. For the liquid phase, the use of a small Stokes number as the perturbation parameater enables a solution of the governing equations to be developed. Influence of the standing wave flow-field on droplet grouping is described by a specially constructed modification of the vaporization Damkohler number. Instantaneous flame front shapes are found via a solution for the usual Schwab–Zeldovitch parameter. Numerical results obtained from the analytical solution uncover the strong bearing that droplet grouping, induced by the standing wave flow-field, can have on flame height, shape, and type (over- or under-ventilated) and on the existence of multiple flame fronts.

Flexo-photoelectronic effect in n-type/p-type two-dimensional semiconductors and a deriving light-stimulated artificial synapse

2021 ◽  
Author(s):  
Xiang Wang ◽  
Xin Zhou ◽  
Anyang Cui ◽  
Menghan Deng ◽  
Xionghu Xu ◽  
...  
Keyword(s):  
Two Dimensional ◽  
2D Semiconductors ◽  
Artificial Synapse ◽  
P Type

We demonstrate flexo-photoelectronic effects of both n-type and p-type 2D semiconductors.

scholarly journals Tetrazine molecules as efficient electronic diversion channel in 2D organic-inorganic perovskites

2021 ◽  
Author(s):  
Ferdinand Lédée ◽  
Pierre Audebert ◽  
Gaëlle Trippé-Allard ◽  
Laurent Galmiche ◽  
Damien Garrot ◽  
...  
Keyword(s):  
Organic Component ◽  
Two Dimensional ◽  
Diversion Channel ◽  
Halide Perovskites ◽  
First Time

We present the synthesis of two novel two-dimensional (2D) hybrid organic-inorganic halide perovskites incorporating for the first time 100% of a photoactive tetrazine derivative as the organic component. With this...

scholarly journals Exfoliation in a low boiling point solvent and electrochemical applications of MoO3

2020 ◽  
Vol 11 ◽  
pp. 662-670
Author(s):  
Matangi Sricharan ◽  
Bikesh Gupta ◽  
Sreejesh Moolayadukkam ◽  
H S S Ramakrishna Matte
Keyword(s):  
Energy Storage ◽  
Electrode Material ◽  
Electronic Devices ◽  
High Specific Capacitance ◽  
Two Dimensional ◽  
Energy Storage Devices ◽  
Intrinsic Nature ◽  
Storage Devices ◽  
Scan Rate ◽  
First Time

MoO3 is a versatile two-dimensional transition metal oxide having applications in areas such as energy storage devices, electronic devices and catalysis. To efficiently utilize the properties of MoO3 arising from its two-dimensional nature exfoliation is necessary. In this work, the exfoliation of MoO3 is carried out in 2-butanone for the first time. The achieved concentration of the dispersion is about 0.57 mg·mL−1 with a yield of 5.7%, which are the highest values reported to date. These high values of concentration and yield can be attributed to a favorable matching of energies involved in exfoliation and stabilization of MoO3 nanosheets in 2-butanone. Interestingly, the MoO3 dispersion in 2-butanone retains its intrinsic nature even after exposure to sunlight for 24 h. The composites of MoO3 nanosheets were used as an electrode material for supercapacitors and showed a high specific capacitance of 201 F·g−1 in a three-electrode configuration at a scan rate of 50 mV·s−1.

Tunable Plasmon Resonances in Two-Dimensional Molybdenum Oxide Nanoflakes

2014 ◽  
Vol 26 (23) ◽  
pp. 3931-3937 ◽  
Author(s):  
Manal M. Y. A. Alsaif ◽  
Kay Latham ◽  
Matthew R. Field ◽  
David D. Yao ◽  
Nikhil V. Medehkar ◽  
...  
Keyword(s):  
Molybdenum Oxide ◽  
Two Dimensional ◽  
Plasmon Resonances

Exciton dynamics and annihilation in WS2 2D semiconductors

Nanoscale ◽  
2015 ◽  
Vol 7 (16) ◽  
pp. 7402-7408 ◽  
Author(s):  
Long Yuan ◽  
Libai Huang
Keyword(s):  
Two Dimensional ◽  
Time Resolved ◽  
Exciton Dynamics ◽  
2D Semiconductors ◽  
Time Resolved Photoluminescence ◽  
2D Crystals

We systematically investigate the exciton dynamics in monolayered, bilayered, and trilayered WS2 two-dimensional (2D) crystals by time-resolved photoluminescence (TRPL) spectroscopy.

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