The Synthesis and Electronic Characteristics of Poly(p-Phenylene Vinylene) Derivatives

A series of soluble poly(p-phenylene vinylene) (PPV) derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials. The electronic characteristics of PPV derivatives were studied.

Effects of Rattling Behavior of K and Cd Atoms along Different Directions in Anisotropic KCdAs on Lattice Thermal Transport and Thermoelectric Properties

We employ advanced first principles methodology,merging self-consistent phonon theory and the Boltzmann transport equation,to comprehensively explore the thermal transport and thermoelectric properties of KCdAs.Notably,the study accounts for the impact of quartic anharmonicity on phonon group velocities in the pursuit of lattice thermal conductivity and investigates 3ph and 4ph scattering processes on phonon lifetimes.Through various methodologies,including examining atomic vibrational modes and analyzing 3ph and 4ph scattering processes,the article unveils microphysical mechanisms contributing to the lowκL within KCdAs.Key features include significant anisotropy in Cd atoms,pronounced anharmonicity in K atoms,and relative vibrations in non-equivalent As atomic layers.Cd atoms,situated between As layers,exhibit rattling modes and strong lattice anharmonicity,contributing to the observed lowκL.Remarkably flat bands near the valence band maximum translate into high PF,aligning with ultralowκL for exceptional thermoelectric performance.Under optimal temperature and carrier concentration doping,outstanding ZT values are achieved:4.25(a(b)-axis,p-type,3×10^(19)cm^(−3),500 K),0.90(c-axis,p-type,5×10^(20)cm^(−3),700 K),1.61(a(b)-axis,n-type,2×10^(18)cm^(−3),700 K),and 3.06(c-axis,n-type,9×10^(17)cm^(−3),700 K).

Effects of 4f Electron Characteristics and Alternation Valence of Rare Earths on Photosynthesis: Regulating Distribution of Energy and Activities of Spinach Chloroplast

Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order： Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.

DC Characteristics of Lattice-Matched InAlN/AlN/GaN High Electron Mobility Transistors

Lattice-matched InAlN/AlN/GaN high electron mobility transistors (HEMTs) grown on sapphire substrate by using low-pressure metallorganic chemical vapor deposition were prepared, and the comprehensive DC characteristics were implemented by Keithley 4200 Semiconductor Characterization System. The experimental results indicated that a maximum drain current over 400 mA/mm and a peak external transconductance of 215 mS/mm can be achieved in the initial HEMTs. However, after the devices endured a 10-h thermal aging in furnace under nitrogen condition at 300 ℃, the maximum reduction of saturation drain current and external transconductance at high gate-source voltage and drain-source voltage were 30% and 35%, respectively. Additionally, an increased drain-source leakage current was observed at three-terminal off-state. It was inferred that the degradation was mainly related to electron-trapping defects in the InAlN barrier layer.

Electron Dynamics and Characteristics of Attosecond Electromagnetic Emissions in Relativistic Laser-Plasma Interactions

Generation of attosecond electromagnetic （EM） pulses and the associated electron dynamics are studied using particle-in-cell simulations of relativistic laser pulses interacting with over-dense plasma foil targets. The inter- action process is found to be so complicated even in the situation of utilizing driving laser pulses of only one cycle. Two electron bunches closely involved in the laser-driven wavebreaking process contribute to attosecond EM pulses through the coherent synchrotron emission process whose spectra are found to follow an exponential decay rule. Detailed investigations of electron dynamics indicate that the early part of the reflected EM emission is the high-harmonics produced through the relativistic oscillating mirror mechanism. High harmonics are also found to be generated through the Bremsstrahlung radiation by one electron bunch that participates in the wavebreaking process and decelerates when it experiences the local wavebreaking-generated high electrostatic field in the moving direction.

Spatial distribution of electron characteristic in argon rf glow discharges

The spatial distributions of the electron density and the mean electron energy of argon radio frequency （rf） glow discharge plasma in a plasma-enhanced chemical vapour deposition （PECVD） system have been investigated using an established movable Langmuir probe. The results indicate that in the axial direction the electron density tends to peak at midway between the two electrodes while the axial variation trend of mean electron energy is different from that of the electron density, the mean electron energy is high near the electrodes. And the mean electron energy near the cathode is much higher than that near the anode. This article focuses on the radial distribution of electron density and mean electron energy. A proposed theoretical model distribution agrees well with the experimental one： the electron density and the mean electron energy both increase from the centre of the glow to the edge of electrodes. This is useful for better understanding the discharge mechanism and searching for a better deposition condition to improve thin film quality.

Numerical simulation and experimental research on an inductively coupled RF plasma cathode

In this study,numerical simulation and discharge current tests were conducted on an inductively coupled radio frequency(RF)plasma cathode.Numerical simulations and experimental measurements were performed to study the factors influencing the electron extraction characteristics,including the gas type,gas flow,input power and extracting voltage.The simulation results were approximately consistent with the experimental results.We experimentally found that the RF input power mainly determines the extracted electron current.An electron current greater than 1 A was acquired at 270 W(RF input power),2.766 sccm(xenon gas).Our results prove that an inductively coupled RF plasma cathode can be reasonable and feasible,particularly for low power electric propulsion devices.

Time of the Energy Emission in the Hydrogen Atom and Its Electrodynamical Background

The time of the energy emission between two neighbouring electron levels in the hydrogen atom has been calculated first on the basis of the quantum aspects of the Joule-Lenz law, next this time is approached with the aid of the electrodynamical parameters characteristic for the electron motion in the atom. Both methods indicate a similar result, namely that the time of emission is close to the time period of the electromagnetic wave produced in course of the emission. As a by-product of calculations, the formula representing the radius of the electron microparticle is obtained from a simple combination of the expressions for the Bohr magnetic moment and a quantum of the magnetic flux.

Insights into channel potentials and electron quasi-Fermi potentials for DG tunnel FETs

A detailed investigation carried out, with the help of extensive simulations using the TCAD device simulator Sentaurus, with the aim of achieving an understanding of the effects of variations in gate and drain potentials on the device characteristics of a silicon double-gate tunnel field effect transistor（Si-DG TFET） is reported in this paper. The investigation is mainly aimed at studying electrical properties such as the electric potential, the electron density, and the electron quasi-Fermi potential in a channel. From the simulation results, it is found that the electrical properties in the channel region of the DG TFET are different from those for a DG MOSFET. It is observed that the central channel potential of the DG TFET is not pinned to a fixed potential even after the threshold is passed（as in the case of the DG MOSFET）; instead, it initially increases and later on decreases with increasing gate voltage, and this is also the behavior exhibited by the surface potential of the device. However, the drain current always increases with the applied gate voltage. It is also observed that the electron quasi-Fermi potential（e QFP）decreases as the channel potential starts to decrease, and there are hiphops in the channel e QFP for higher applied drain voltages. The channel regime resistance is also observed for higher gate length, which has a great effect on the I–V characteristics of the DG TFET device. These channel regime electrical properties will be very useful for determining the tunneling current; thus these results may have further uses in developing analytical current models.