- 标题
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- 实验方案
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Picosecond-Range Avalanche Switching of Bulk Semiconductors Triggered by Steep High-Voltage Pulses
摘要： Experimental observation and numerical simulations of sub-nanosecond avalanche switching of Si and ZnSe bulk semiconductor structures initiated by high-voltage pulses with steep (dU/dt > 10 kV/ns) ramp are reported. The measured switching time is ～100 ps. The switching is sustainable and repetitive and has negligible jitter. Comparison of the experimental and numerical results suggests that after switching, the whole volume of the structure is uniformly ?lled with nonequilibrium electron–hole plasma.
关键词： semiconductor lasers,Power electronics,pulse-power system switches
更新于2025-09-23 15:21:21
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[IEEE 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Greifswald, Germany (2018.9.23-2018.9.28)] 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Research on Hybrid Reactive Power Compensation Switch Based on Vacuum Switch
摘要： In the field of low and medium voltage reactive power compensation, the switching of capacitor groups based on phase-controlled switching technology is a better way than others. However, the accuracy and reliability of contacts switching point are the key factors affecting the work efficiency. It is technically difficult to meet all the requirements. In recent years, ABB has proposed a phase-choosing model based on the hybrid device composed of semiconductor and mechanical switches, which has a certain effect on suppressing the transient effect of reactive power compensation. Based on the ABB model, this paper presents an optimization model of Y- connection hybrid switching system of vacuum switch and power electronic device, and studies the switching strategy of the model. The simulation and the tests show its effectiveness in suppressing transient problems. Compared with the traditional phase-controlled switch technology, the new scheme will help the switch work in a wide phase range for avoiding transient effect. It is demanded that the new method has more tolerance to the dispersion of the operating mechanism, and more benefit to the realization of the flexible phase -choosing technology.
关键词： semiconductor,hybrid switch,reactive power compensation,DSP
更新于2025-09-23 15:21:21
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Influence of adsorbates on the performance of a field emitter array in a high voltage triode setup
摘要： The influence of residual gas pressure on the characteristics of black-Silicon field emitter arrays in a high voltage triode setup is investigated. I-V-characteristics at different pressure levels show a decrease of emission current with rising pressure. This can be explained by an increase of the work function and charging of the emitter surface due to adsorbates. The initial characteristics can be restored by heating the FEA up to 110 °C during electron emission. This regeneration procedure enables an extension of the lifetime from about 20 h to 440 h at a residual gas pressure of 10-5 mbar.
关键词： silicon tips,emission current stability,semiconductor field emission,field emitter array
更新于2025-09-23 15:21:21
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Heterogeneous photocatalyzed C-C cross-coupling reactions under visible-light and near-infrared light irradiation
摘要： With the development of photocatalytic technology and organic synthesis chemistry, the photocatalyzed cross-coupling reaction provides one of the most attractive methodologies for the C-C bond formation and has been booming in recent years. The advantages of the heterogeneous photocatalyzed C-C cross-coupling reaction lie in its environment friendly, easily separated and conveniently recovered catalysts. In this review, we summarized and highlighted recent achievements of heterogeneous photocatalyzed C-C cross-coupling reactions through four aspects: visible light induced C-C cross-coupling reactions catalyzed by Pd supported semiconductor photocatalysts; visible light induced C-C cross-coupling reactions catalyzed by Pd based plasmonic photocatalysts; visible light induced C-C cross-coupling reactions catalyzed by palladium-free photocatalysts; near-infrared light induced C-C cross-coupling reactions.
关键词： Photocatalysis,semiconductor,C-C cross-coupling,localized surface plasmon resonance,Pd
更新于2025-09-23 15:21:21
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Parallel domain decomposition methods for a quantum-corrected drift–diffusion model for MOSFET devices
摘要： In this paper, we describe parallel domain decomposition methods based on the restricted additive Schwarz (RAS) method for a quantum-corrected drift-diffusion (QCDD) model for MOSFET devices. We have developed hybrid Message Passing Interface (MPI)/OpenMP parallelization algorithms of the QCDD system. For internode parallelization, two extensions of the RAS method are newly developed for the QCDD model. For intranode parallelization, we combine the conjugate gradient (CG) and BiCGSTAB procedures with a splitting-up operator method to realize parallelization of the incomplete factorization. The parallel numerical results for a three-dimensional Si bulk n-MOSFET on a multi-core NEC SX-ACE parallel computer are demonstrated. The intranode parallel numerical results are further evaluated on a many-core Cray XC40 parallel computer.
关键词： Restricted additive Schwarz method,Domain decomposition method,Numerical methods,Device simulation,Semiconductor,quantum-corrected drift–diffusion model
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Influence of Dissipations in the Semiconductor Layers on the Properties of Hybrid Surface Waves at the Interface Between Porous Nanocomposite and Hypercrystal
摘要： Dispersion properties of surface electromagnetic waves at the plane interface of nanocomposite made of semiconductor inclusions and a hypercrystal under different electron collision frequency and electron concentration are studied. Effective medium theory was applied in order to describe the contacting materials. The nanocomposite as well as the hypercrystal includes semiconductor layers made of n-InSb. Temperature models for concentration of charge carriers as well as mobility of charge carriers are applied to describe the physical properties of n-InSb material. On raising the temperature, the layers of n-InSb and, consequently, contacting composites, transform from a weakly dissipative materials to highly dissipative in the terahertz and optical frequencies. It is shown, that influence of dissipations in the semiconductor material results in the arising of additional surface waves branches, standard surface plasmon polaritons and Dyakonov surface waves, changes in frequency domains, angular existence domains, and penetration depth. Moreover, Dyakonov surface wave’s branches can exist in the ranges where they are prohibited in the case of lossless materials.
关键词： surface waves,nanocomposite,semiconductor,metamaterial
更新于2025-09-23 15:21:21
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Highly transparent zinc nitride thin films by RF magnetron sputtering with enhanced optoelectronic behavior
摘要： Transparent semiconducting nitrides are important materials for many modern technologies. Here, optical transparent semiconducting zinc nitride (Zn3N2) thin films have been developed by reactive RF magnetron sputtering at different nitrogen (N2) contents. The deposited films are found to be cubic with preferred orientation of (3 2 1) plane. High optical transmittance (～96%) and refractive index (1.32) at the wavelength of 500 nm and optical band gap of 3.1 eV have been observed for the films deposited at 45% nitrogen content. The investigation on other optical constants such as extinction coefficient and dielectric constant as a function of wavelength shows enhanced optical behavior. The Zn3N2 thin films show n-type conductivity with carrier concentration of ～1020–1021 cm?3, mobility in the range of 4 to 56 cm2/Vs (which is 1–2 times higher than the values of TCOs) and resistivity around 10?4 Ωcm as a function of nitrogen content. These results suggested that Zn3N2 thin films could perform as potential transparent semiconductors for thin film solar cells.
关键词： Electron mobility,Zinc nitride,Optical constants,Transparent semiconductor,Reactive RF sputtering
更新于2025-09-23 15:21:21
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Megasonic Enhanced Photo Resist Removal Using Unique Solvent Free Phase-Fluids on an Advanced Single Wafer Resist Processing System
摘要： In this work the application of a new generation of phase-fluid stripping to a variety of semiconductor photoresists was studied. The unique water based intelligent fluid formulas used in these experiments were all VLSI grade, copper compatible and non-toxic. The first phase of experiments was to establish if there was a reaction with the photoresist type and intelligent fluid? formula within a reasonable time period, with the most promising combinations carried forward to phase two for in depth study. The follow-on experimental results demonstrate the optimal process parameters through variation of process temperature settings and the additions of megasonic acoustic energy. Photoresist stripping results were quantified though visual inspection and contact angle measurement.
关键词： photoresist stripping,semiconductor,intelligent fluid,phase-fluid,megasonic
更新于2025-09-23 15:21:21
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Can one introduce long range ferromagnetism by doping transition metal in wide band gap semiconducting ZnO?
摘要： In this report, we present a systematic study of magnetic behavior of transition metal (TM = Fe or Cu) doped ZnO and co-doped (Cu, Fe) ZnO nanoparticles. All the samples show antiferromagnetic (AFM) like inverse susceptibility at low temperatures. In all the samples AFM Curie-Weiss temperature TAF M increases with increase in TM ion concentration indicating enhanced antiferromagnetic correlation upon TM doping. We observe a crossover from antiferromagnetic correlation state to ferromagnetic correlation around temperature (T) 100 - 150K. We shall try to explain all the experimental observations by invoking the role of oxygen vacancies, valency of transition metal ions, formation and interaction between bound magnetic polaron (BMP) and their melting in ZnO matrix. Even though we observe ferromagnetic correlation around room temperature in all these samples from the inverse magnetic susceptibility data, but no true long range ferromagnetic transition was observed in magnetization down to lowest measured temperature of 5K. Our study indicates the di?culties in achieving long range ferromagnetism arising due to the formation of BMPs upon lowering the temperature where these BMPs get antiferromagnetically correlated due to superexchange interaction occurring in transition metal doped wide band gap semiconducting ZnO matrix.
关键词： Dilute magnetic semiconductor,Bound magnetic polaron,Antiferromagnetism,Transition metal doping,ZnO,Ferromagnetism
更新于2025-09-23 15:21:21
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Electron–hole correlations govern Auger recombination in nanostructures
摘要： The fast nonradiative decay of multiexcitonic states via Auger recombination is a fundamental process affecting a variety of applications based on semiconductor nanostructures. From a theoretical perspective, the description of Auger recombination in confined semiconductor nanostructures is a challenging task due to the large number of valance electrons and exponentially growing number of excited excitonic and biexcitonic states that are coupled by the Coulomb interaction. These challenges have restricted the treatment of Auger recombination to simple, noninteracting electron–hole models. Herein we present a novel approach for calculating Auger recombination lifetimes in confined nanostructures having thousands to tens of thousands of electrons, explicitly including electron–hole interactions. We demonstrate that the inclusion of electron–hole correlations are imperative to capture the correct scaling of the Auger recombination lifetime with the size and shape of the nanostructure. In addition, correlation effects are required to obtain quantitatively accurate lifetimes even for systems smaller than the exciton Bohr radius. Neglecting such correlations can result in lifetimes that are 2 orders of magnitude too long. We establish the utility of the new approach for CdSe quantum dots of varying sizes and for CdSe nanorods of varying diameters and lengths. Our new approach is the first theoretical method to postdict the experimentally known “universal volume scaling law” for quantum dots and makes novel predictions for the scaling of the Auger recombination lifetimes in nanorods.
关键词： semiconductor nanocrystals,quantum dots,excitons,auger recombination,biexcitons,nanorods
更新于2025-09-23 15:21:21