- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- computer statistical experiment
- statistical optimization
- resonant-tunneling diode
- negative voltage current differential resistance
- characteristics
- heterojunction
- quantum well
- resonant tunneling border
- Electronic Science and Technology
- Optoelectronic Information Science and Engineering
- Bauman Moscow State Technical University
- V.N. Karazin Kharkiv National University
-
The merging mechanisms of poly(3-hexylthiophene) domains revealed through scanning tunneling microscopy and molecular dynamics simulations
摘要： Herein, we in situ track the merging processes of poly(3-hexylthiophene) (P3HT) domains physisorbed onto graphite while keeping the domain structures clearly resolved through scanning tunneling microscopy (STM). The domain shape-fixed, amoeba/worm-like and bridge-mediated merging mechanisms are revealed. In the domain shape-fixed diffusion, the moving domains obey the principle of the non-continuous random walks. Both diffusive and ballistic-like dynamics are disclosed. Additionally, the asymmetrical domains may show anisotropic movements. In the amoeba-like style, the pseudopodia are formed and changed stochastically while in the worm-like style two permanent parts (head and body) of the domains are formed prior movement and kept fixed in the motions. Finally, the integration of two domains is called a bridge-mediated one, if a small domain is bound to a bigger one directly through a dynamic bridge. The molecular dynamics simulations support the experimental findings of P3HT domain movements and rotations on the graphite surface.
关键词： Surface diffusion,Poly(3-hexylthiophene),Scanning tunneling microscopy
更新于2025-09-19 17:13:59
-
[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Thin Film Photosensor Integrated on Planar Waveguide for Lab-an-Chip Applications
摘要： We report on high-frequency performance and temperature stability of zero-bias GaAsSb/InAlAs/InGaAs tunnel diodes for millimeter-wave detection in 220–330-GHz band. The average voltage sensitivity of 1400 V/W has been achieved in 0.8 × 0.8 μm2 mesa devices at room temperature. Measured current–voltage characteristics revealed a superior temperature stability of the devices compared with Schottky barrier diodes. The expected sensitivity variations over a temperature range from T = 17–300 K are 1.7 dB.
关键词： tunnel diode,tunneling,Backward diode,millimeter wave and terahertz detectors,semiconductor nanostructures
更新于2025-09-19 17:13:59
-
Laser-driven tunneling photocurrent as a source of midinfrared to microwave multidecade supercontinua yoked to high-order harmonics
摘要： Electron tunneling induced by a strong-field laser driver can lead to an ultrafast stepwise buildup of the photoelectron density ρ. When the laser field is strong enough, each such step in the temporal profile of ρ is confined well within the field cycle, providing an ultrabroadband, multidecade force that drives the photoelectron current j. However, whether or not the photocurrent can emit electromagnetic radiation with such an extraordinarily broad spectrum depends on the damping, which defines the low-frequency cutoff in the spectrum of this radiation. We show that, with a suitable choice of the gas pressure and parameters of the laser driver, the laser-induced tunneling photocurrent can serve as a source of a remarkably broadband electromagnetic radiation with a multidecade spectrum stretching from the vacuum ultraviolet all the way down to the microwave range. We demonstrate that the supercontinuum fields emitted by individual photocurrent steps, induced by different field half cycles, can coherently combine, giving rise to well-resolved high-order harmonics on the high-frequency end of the spectrum yoked to a bright midinfrared to microwave supercontinuum, dominating the long-wavelength part of the multidecade radiation output.
关键词： high-order harmonics,photocurrent,supercontinua,microwave,midinfrared,laser-driven tunneling
更新于2025-09-19 17:13:59
-
Multiscroll chaotic attractors in Optical Injected Semiconductor Laser Driven by a Resonant Tunneling Diode Current
摘要： This paper shows a complex nonlinear dynamics of an optically injected laser diode (LD) between a free-running laser and a perturbed laser. A bifurcation diagram analysis sustained Lyapunov exponents’ spectra reveals chaotic and quasi-periodic dynamics for restricted ranges of directly modulated by electrical current from a resonant tunneling diode (RTD) circuit. The LD model evolves a new control parameter called effective gain coefficient (EGC) and can switch the frequency ??????and by EGC variations, including the generation of the hyperchaotic regime and multiscroll chaotic attractors through a cascade of periodic oscillations to the chaos. Moreover, an implementation of this new coupled system also shows that when an AC signal ?????? ??????(2??????????) is added to the DC voltage bias, the LD outputs show several optical signals such as periodic, injection.
关键词： chaotic attractors,optical injection,semiconductor laser,resonant tunneling diode,Optoelectronic circuit
更新于2025-09-19 17:13:59
-
[IEEE 2019 19th Non-Volatile Memory Technology Symposium (NVMTS) - Durham, NC, USA (2019.10.28-2019.10.30)] 2019 19th Non-Volatile Memory Technology Symposium (NVMTS) - Novel Quantum Dot Based Memories with Many Days of Storage Time : Last Steps towards the Holy Grail?
摘要： The feasibility of the QD-Flash concept, its fast write and erase times, is demonstrated together with storage times of 4 days at room temperature. The storage time of holes in (InGa)Sb QDs embedded in a (AlGa)P matrix can be extended by growth modifications to 10 y. Tunneling structures were recently demonstrated to solve the trade-off conflict between storage time and erase time. A QD-NVSRAM is suggested to become the first commercial application.
关键词： tunneling,quantum dots,NVSRAM,QD-flash
更新于2025-09-19 17:13:59
-
Interfacial Energetic Level Mapping and Nano-Ordering of Small Molecule/Fullerene Organic Solar Cells by Scanning Tunneling Microscopy and Spectroscopy
摘要： Using scanning tunneling microscopy (STM) and spectroscopy (STS) at the liquid/solid interface, morphology evolution process and energetic level alignment of very thin solid films (thickness: <700 pm), of the low molecular weight molecule DRCN5T and DRCN5T:[70]PCBM blend are analyzed after applying thermal annealing at different temperatures. These films exhibit a worm-like pattern without thermal annealing (amorphous shape); however, after applying thermal annealing at 120 °C, the small molecule film domains crystallize verified by X-ray diffraction: structural geometry becomes a well-defined organized array. By using STS, the energy band diagrams of the semiconductor bulk heterojunction (blended film) at the donor-acceptor interface are determined; morphology and energy characteristics can be correlated with the organic solar cells (OSC) performance. When combining thermal treatment and solvent vapor annealing processes as described in previous literature by using other techniques, OSC devices based on DRCN5T show a very acceptable power conversion efficiency of 9.0%.
关键词： solvent vapor annealing,DRCN5T,scanning tunneling spectroscopy,organic solar cells,scanning tunneling microscopy,thermal annealing
更新于2025-09-16 10:30:52
-
Light emission properties in a double quantum dot molecule immersed in a cavity: Phonon-assisted tunneling
摘要： Two main mechanisms dictate the tunneling process in a double quantum dot: overlap of excited wave functions, effectively described as a tunneling rate, and phonon-assisted tunneling. In this paper, we study different regimes of tunneling that arise from the competition between these two mechanisms in a double quantum dot molecule immersed in a unimodal optical cavity. We show how such regimes affect the mean number of excitations in each quantum dot and in the cavity, the spectroscopic resolution and emission peaks of the photoluminescence spectrum, and the second-order coherence function which is an indicator of the quantumness of emitted light from the cavity.
关键词： Double quantum dot,Light-matter interaction,Second-order coherence function,Phonon-assisted tunneling
更新于2025-09-16 10:30:52
-
Fast Response Solar-Blind Photodetector with a Quasi-Zener Tunneling Effect Based on Amorphous In-Doped Ga2O3 Thin Films
摘要： A high-performance solar-blind photodetector with a metal–semiconductor–metal structure was fabricated based on amorphous In-doped Ga2O3 thin films prepared at room temperature by radio frequency magnetron sputtering. The photodetector shows a high responsivity (18.06 A/W) at 235 nm with a fast rise time (4.9 μs) and a rapid decay time (230 μs). The detection range was broadened compared with an individual Ga2O3 photodetector because of In doping. In addition, the uneven In distribution at different areas in the film results in different resistances, which causes a quasi-Zener tunneling internal gain mechanism. The quasi-Zener tunneling internal gain mechanism has a positive impact on the fast response speed and high responsivity.
关键词： quasi-Zener tunneling effect,fast response,amorphous InGaO thin films,solar-blind photodetector
更新于2025-09-16 10:30:52
-
Controlling light tunneling by adiabatic passage in two modulated nonlinear waveguides
摘要： We theoretically investigate light propagation in two coupled nonlinear waveguides with a certain static propagation constant detuning between two waveguides and with the linear refractive index modulated along the propagation direction. By slowly varying the amplitude of modulation, we steer the light to the desired output waveguide when equal amounts of lights are launched into each waveguide. We reveal that depending on the sign of the static propagation constant mismatch (detuning) between two waveguides, the launched light can be completely switched to either of waveguides. Additionally, we numerically examine the performances of light switching for general inputs and modulation amplitudes, and show that the localization of output light is robust against small to moderate variations in the ?nal modulation amplitude, phase di?erence and intensity distribution of input ?eld between two waveguides. More importantly, according to the principle of the proposed scheme, we are capable of steering the output light to the targeted waveguide at extremely low input power. In theory, our ?ndings can be explained qualitatively by means of adiabatic navigation of the so-called nonlinear Floquet states.
关键词： Light tunneling,Nonlinear waveguides,Adiabatic passage
更新于2025-09-16 10:30:52
-
Self-assembled Ag(111) nanostructures induced by Fermi surface nesting
摘要： Scanning tunneling microscopy measurements on Ag(111)/MoS2 reveal atomically ?at preferred, or “magic,” heights occurring at 6, 10, and 14 atomic layers. These results are consistent with Ag growth on a variety of semiconducting substrates and correlate with electronic energy savings in electronic structure calculations of freestanding Ag(111) ?lms. Thus, under certain conditions, Ag will spontaneously form quantized structures independent of the substrate. To explain this, we have found Fermi surface nesting vectors in the bulk Ag band structure which account for these results and the fact Ag that is gapped along the surface normal. This model extends to a range of metallic systems which exhibit electronic con?nement, epitaxial growth, and minimal strain. As with Au/MoS2, the Ag/MoS2 system exhibits this behavior at unusually high temperatures so that these principles might be used for control over device features at the nanometer scale under standard fabrication conditions.
关键词： quantum size effects,MoS2,Fermi surface nesting,Ag(111),scanning tunneling microscopy
更新于2025-09-16 10:30:52