- 标题
- 摘要
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- 实验方案
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Modeling and Simulation of Comprehensive Diode Behavior under Electrostatic Discharge Stresses
摘要： Diodes are effective devices for Electrostatic Discharge (ESD) protection. To accurately predict ESD robustness through circuit simulation of protection architectures in integrated circuits that use diodes, an enhanced model is proposed. This model is constructed with several compact model elements to simulate all physical device behaviors under high current transient ESD conditions, namely voltage overshoot, on-resistance variation, and thermal failure. The proposed model implements a thermal monitor, which can not only correlate current – voltage characteristics with the self-heating effect, but accurately predicts thermal failure under different pulse width conditions. The simulation results of this comprehensive diode model benchmarked against measurements are also reported.
关键词： junction thermal failure,Electrostatic discharge (ESD),thermal network,transmission line pulse (TLP),on-resistance variation,overshoot
更新于2025-09-23 15:21:21
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Van der Waals junction field effect transistors with both n- and p-channel transition metal dichalcogenides
摘要： Two-dimensional (2D) transition metal dichalcogenides (TMDs)-based van der Waals (vdW) PN junctions have been used for heterojunction diodes, which basically utilize out-of-plane current across the junction interface. In fact, the same vdW PN junction structure can be utilized for another important device application, junction field effect transistors (JFETs), where in-plane current is possible along with 2D–2D heterojunction interface. Moreover, the 2D TMD-based JFET can use both p- and n-channel for low voltage operation, which might be its unique feature. Here we report vdW JFETs as an in-plane current device with heterojunction between semiconducting p- and n-TMDs. Since this vdW JFET would have low-density traps at the vdW interface unlike 2D TMD-based metal insulator semiconductor field effect transistors (MISFETs), little hysteresis of 0.0–0.1 V and best subthreshold swing of ~100 mV/dec were achieved. Easy saturation was observed either from n-channel or p-channel JFET as another advantage over 2D MISFETs, exhibiting early pinch-off at ~1 V. Operational gate voltage for threshold was near 0 V and our highest mobility reaches to ~>500 cm2/V·s for n-channel JFET with MoS2 channel. For 1 V JFET operation, our best ON/OFF current ratio was observed to be ~104.
关键词： n-channel,field effect transistors,van der Waals junction,transition metal dichalcogenides,p-channel
更新于2025-09-23 15:21:21
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[IEEE 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Brasov, Romania (2019.11.3-2019.11.6)] 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Stable Operation of an Automotive Photovoltaic System under Moving Shadows
摘要： This paper presents a simple mathematical expression to model the effect of statistical dopant fluctuations on threshold voltage (Vth) of junction field-effect transistors (JFETs). The random discrete doping (RDD) in the active device area is used to derive an analytical model to compute the standard deviation, σ Vth,RDD of the Vth-distribution for any arbitrary channel doping profiles. The model shows that the Vth-variability in JFETs depends on the active device area, channel doping concentration, and the depth of the channel depletion region of the gate/channel pn-junction. The model is applied to compute σ Vth,RDD for symmetric and asymmetric source/drain double-gate n-channel JFETs. The simulation results show that the model can be used for predicting Vth-variability in JFETs.
关键词： statistical dopant fluctuations,random discrete doping,process variability in JFETs,modeling threshold voltage variability,JFET threshold voltage variability,Junction field-effect transistor (JFET)
更新于2025-09-23 15:21:01
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Performance modeling and analysis of high-concentration multi-junction photovoltaics using advanced hybrid cooling systems
摘要： This paper presents the performance modeling and analysis of the high-concentration multi-junction photovoltaic cells, using either constant-width one-section or two-stepwise microchannels-jet impingement hybrid cooling system. The performance simulation and analysis of the cells are conducted using a three dimensional-Computational Fluid Dynamics program for various operating parameters, including water flow rate (100–1300 mL/min.), inlet water temperature (10–80 °C), and heat flux (10–90 W/cm2 corresponding to concentration ratios of 250–2250). The thermal and electrical characteristics of the cells are correlated in dimensionless form as functions of the direct normal irradiance and the operating and geometrical parameters of the hybrid cooling systems. The developed high-quality explicit performance model correlations assist in the design, performance prediction, and selection of operation strategy of photovoltaic cells. The results indicated that the generated and net output power is directly proportional to the applied heat flux (concentration ratio) and inversely proportional to the inlet water temperature. Temperature uniformity of the photovoltaic base enhances with the water flow rate, deteriorates with heat flux, and less affected by the inlet temperature, particularly for the two-sections cooling system. The pumping power increases with water flow rate and decreases as both inlet temperature or heat flux increases. Heat transfer characteristics enhance significantly with water flow rate, moderately with inlet water temperature and slightly with heat flux.
关键词： Photovoltaic performance modeling,High-concentration multi-junction photovoltaic,Operating parameters,Microchannels heat sink,Electrical power correlations
更新于2025-09-23 15:21:01
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Systematic Modulation of Charge Transport in Molecular Device through Facile Control of Molecule-Electrode Coupling using Double Self-assembled Monolayers Nanowire Junction
摘要： We report a novel solid-state molecular device structure based on double self-assembled monolayers (D-SAMs) incorporated into the suspended nanowire architecture to form “Au | SAM-1 || SAM-2 | Au” junction. Using commercially available thiol molecules that are devoid of synthetical difficulty, we constructed Au | S-(CH2)6-Ferrocene || SAM-2 | Au junction, with various length and chemical structure of SAM-2 to tune the coupling between ferrocene conductive molecular orbital and electrode of the junction. Combining low noise and wide temperature range measurement, we demonstrated systematically modulated conduction depending on the length and chemical nature of SAM-2. Meanwhile, transport mechanism transition from tunneling to hopping, and the intermediate state accompanied by the current fluctuation due to the coexistence of the hopping and tunneling transport channels, were observed. Considering the versatility of this solid-state D-SAMs in modulating the electrode-molecule interface and electroactive groups, this strategy thus provides a novel facile strategy for tailorable nanoscale charge transport study and functional molecular devices.
关键词： charge transport,molecular device,nanowire junction,self-assembled monolayers,ferrocene
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Micro-Prism Spectrum Splitting Optics for Lateral-Arrayed Multi Junction Micro CPV
摘要： A micro-prism-array based low-profile spectrum splitting optics assembly is demonstrated. The precisely-controlled physical profile via low-cost plastic molding contributes to high optical transmission. The conjugate prism design and material matching design allow efficient spectrum splitting while introducing minimal beam deflection. This optics provides a cost-effective module assembly enabling high performance, lateral-arrayed multi-junction micro CPV modules.
关键词： multi-junction cells,spectrum splitting,lateral structure,optics,micro-CPV
更新于2025-09-23 15:21:01
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Klein collimation by rippled graphene superlattice
摘要： The hybridization of σ and π orbitals of carbon atoms in graphene depends on the surface curvature. Considering a single junction between flat and rippled graphene subsystems, it is found an accumulation of charge in the rippled subsystem due to Klein penetration phenomenon that gives rise to n–p junction. Using this fact, we show that the momentum distribution of electrons in ballisitically propagating beam can be selective without a waveguide, or external electric, and/or magnetic fields in graphene strip under experimentally feasible one-dimensional periodic potential. Such a potential is created with the aid of superlattice that consists of periodically repeated graphene pieces with different hybridizations of carbon orbits, produced by variation of the graphene surface curvature. The charge redistribution and selected transmission of electrons, caused by the superlattice, allows to control the electron focusing in the considered system by simply changing the element properties in the superlattice.
关键词： n–p junction,collimation,graphene,ripples
更新于2025-09-23 15:21:01
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[IEEE 2019 Device Research Conference (DRC) - Ann Arbor, MI, USA (2019.6.23-2019.6.26)] 2019 Device Research Conference (DRC) - Tunable WSe <sub/>2</sub> phototransistor enabled by electrostatically doped lateral p-n homojunction
摘要： This study demonstrates an approach to tune the responsivity and detectivity of a WSe2 phototransistor by incorporating an electrostatically doped lateral p-n junction in the form of side gates to the transistor channel. The resulting decrease in dark current and enhancement in photocurrent by externally injected carriers into the conduction channel leads to improved photodetection with a fast response time (τ).
关键词： photodetection,phototransistor,lateral p-n junction,electrostatic doping,WSe2
更新于2025-09-23 15:21:01
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Colloidal Quantum-Dots/Graphene/Silicon Dual-Channel Detection of Visible Light and Short-Wave Infrared
摘要： Integration of infrared detectors with current silicon-based imagers would not only extend their spectral sensing range but also enables numerous applications including thermal imaging, machine vision, and spectrometers. Here, we report the development of a dual-channel photodetector by depositing a colloidal quantum dot (CQDs) infrared photodiode onto a graphene/p-Silicon Schottky diode to provide simultaneous visible and infrared photoresponse channels. The HgTe photodiode is patterned into a semitransparent mesh-structure so that the visible light reaches the Silicon substrate with varying fill factors. The graphene/silicon Schottky junction has a responsivity of ~0.9 A/W in the visible and the infrared CQDs photodiode has a detectivity of ~5×109 Jones at 2.4μm, for a filling factor of 0.1.
关键词： Photodetectors,Graphene/silicon Schottky junction,Visible/infrared,Colloidal quantum dots
更新于2025-09-23 15:21:01
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Counter-intuitive junction temperature behavior in AlGaN-based deep-ultraviolet light-emitting diodes
摘要： The junction temperature, one of the major parameters that strongly affect the performance of light-emitting diodes (LEDs), increases during operation because of the power dissipated as heat within an LED device. Therefore, LED devices with poor characteristics are expected to have higher junction temperatures for the same driving conditions. In this study, an observation contrary to this expectation is presented: a deep-ultraviolet LED device with superior electrical characteristics shows a higher junction temperature at the same input electrical power than a device with poor characteristics. A simple equivalent circuit comprising a diode, a series resistor, and shunt components is employed to elucidate this counter-intuitive observation by considering the possible heat sources inside the LED device. It is found that the junction temperature is mainly dominated by the power dissipated at the diode instead of the other possible heat sources including the Joule heating effect of the resistive components.
关键词： junction temperature,Joule heating,AlGaN-based deep-ultraviolet light-emitting diodes,power dissipation,equivalent circuit
更新于2025-09-23 15:21:01