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Tuning the Spectrum Properties of Fullerene C60: Using a Strong External Electric Field
摘要： The electric ?eld can change the absorption of fullerene C60 to different wavelengths of light by affecting the vibrational modes and electronic transitions. The IR spectrum of fullerene C60 under the strong electric ?eld is studied on B3LYP/6-31G* basis set using density function theory. With the external electric ?eld decreasing, silent modes Hg(1), Ag(1), Gu(2), Hg(5), Ag(2), Hu(7) become active. Meanwhile, UV–Vis spectrum, the excitation energy, excitation wavelength and oscillator strength of ?rst fourteen excited states of fullerene C60 under the ?eld are also studied in B3LYP/6-31G* basis set using time-dependent density functional theory. With the electric ?eld increasing, the absorption peak of fullerene C60 occurs then shifts towards the long-wave region. The excitation energy decrease and the excitation wavelength increase correspondingly, and external electric ?eld makes fullerene C60 absorb energy from 1.01 to 2.31 eV in theory. The energy gap decreases drastically from 2.74 to 1.38 eV, which contributed to tune the energy gap of fullerene C60 by the effect of the electric ?eld in a wide range. It is possible to use electric ?eld to tune fullerene C60 into new energy storage material.
关键词： External electric ?eld,Excited state,Cluster,IR spectrum,Fullerene C60
更新于2025-09-23 15:23:52
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Simulation of Silicon Heterojunction Solar Cells for High Efficiency with Lithium Fluoride Electron Carrier Selective Layer
摘要： In this work, to ameliorate the quantum e?ciency (QE), we made a valuable development by using wide band gap material, such as lithium ?uoride (LiFx), as an emitter that also helped us to achieve outstanding e?ciency with silicon heterojunction (SHJ) solar cells. Lithium ?uoride holds a capacity to achieve signi?cant power conversion e?ciency because of its dramatic improvement in electron extraction and injection, which was investigated using the AFORS-HET simulation. We used AFORS-HET to assess the restriction of numerous parameters which also provided an appropriate way to determine the role of diverse parameters in silicon solar cells. We manifested and preferred lithium ?uoride as an interfacial layer to diminish the series resistance as well as shunt leakage and it was also bene?cial for the optical properties of a cell. Due to the wide band gap and better surface passivation, the LiFx encouraged us to utilize it as the interfacial as well as the emitter layer. In addition, we used the built-in electric and band o?set to explore the consequence of work function in the LiFx as a carrier selective contact layer. We were able to achieve a maximum power conversion e?ciency (PEC) of 23.74%, ?ll factor (FF) of 82.12%, Jsc of 38.73 mA cm?2, and Voc of 741 mV by optimizing the work function and thickness of LiFx layer.
关键词： electric ?eld,silicon heterojunction solar cell,lithium ?uoride,electron selectivity contact layer,work function
更新于2025-09-23 15:21:01
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Thermal properties and remnant state variables of ferroelectric ceramics switched by both electric field and compressive stress at room temperature
摘要： A commercial poled ferroelectric cube specimen is subject to electric ?eld and compressive stress of various magnitudes at the reference temperature 20 °C. After reaching speci?c states of remnant polarization and remnant strains, temperature of the specimen increases under no external load, measuring changes in polarization and strains. Assuming constant values of thermal properties in the temperature range of interest, we estimated pyroelectric and thermal expansion coe?cients for all tested levels of electric and stress ?elds and plotted them versus remnant state variables at 20, 50, 80, and 110 °C. The distributions of thermal properties ?t well into quadratic curves independent of electric and stress ?elds at each of the four temperatures. One could predict successfully the quadratic ?tting curves at high temperatures by using the equations of quadratic ?tting curves at reference temperature. Remnant state variables also seem to have close correlation among themselves, independent of the levels of applied electric ?eld or stress. ? 2018 The Japan Society of Applied Physics
关键词： thermal properties,compressive stress,electric ?eld,ferroelectric ceramics,remnant state variables
更新于2025-09-23 15:21:01
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Optical Recording of Action Potential Initiation and Propagation in Mouse Skeletal Muscle Fibers
摘要： Skeletal muscle ?bers have been used to examine a variety of cellular functions and pathologies. Among other parameters, skeletal muscle action potential (AP) propagation has been measured to assess the integrity and function of skeletal muscle. In this work, we utilize 1-(3-sulfonatopropyl)-4[b[2-(Di-n-octylamino)-6-naphtyl]vinyl]pyridinium betaine, a potentiometric dye, and mag-?uo-4, a low-af?nity intracellular Ca2tindicator, to noninvasively and reliably measure AP conduction velocity in skeletal muscle. We used remote extracellular bipolar electrodes to generate an alternating polarity electric ?eld that initiates an AP at either end of the ?ber. Using enzymatically dissociated ?exor digitorum brevis (FDB) ?bers and high-speed line scans, we determine the conduction velocity to be (cid:2)0.4 m/s. We applied these methodologies to FDB ?bers under elevated extracellular potassium conditions and con?rmed that the conduction velocity is signi?cantly reduced in elevated [Kt]o. Because our recorded velocities for FDB ?bers were much slower than previously reported for other muscle groups, we compared the conduction velocity in FDB ?bers to that of extensor digitorum longus (EDL) ?bers and measured a signi?cantly faster velocity in EDL ?bers than FDB ?bers. As a basis for this difference in conduction velocity, we found a similarly higher level of expression of Nat channels in EDL than in FDB ?bers. In addition to measuring the conduction velocity, we can also measure the passive electrotonic potentials elicited by pulses by applying tetrodotoxin and have constructed a circuit model of a skeletal muscle ?ber to predict passive polarization of the ?ber by the ?eld stimuli. Our predictions from the model ?ber closely resemble the recordings acquired from in vitro assays. With these techniques, we can examine how various pathologies and mutations affect skeletal muscle AP propagation. Our work demonstrates the utility of using 1-(3-sulfonatopropyl)-4[b[2-(Di-n-octylamino)-6-naphtyl]vinyl]pyridinium betaine or mag-?uo-4 to noninvasively measure AP initiation and conduction.
关键词： potentiometric dye,action potential,Nat channels,skeletal muscle,Ca2t indicator,conduction velocity,electric ?eld stimulation
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE High Power Diode Lasers and Systems Conference (HPD) - Coventry, United Kingdom (2019.10.9-2019.10.10)] 2019 IEEE High Power Diode Lasers and Systems Conference (HPD) - Applications of thermoreflectance imaging to high-power diode laser diagnostics
摘要： A time-domain electric ?eld volume integral equation (TD-EFVIE) solver is proposed for characterizing transient electromagnetic wave interactions on high-contrast dielectric scatterers. The TD-EFVIE is discretized using the Schaubert–Wilton–Glisson (SWG) and approximate prolate spherical wave (APSW) functions in space and time, respectively. The resulting system of equations cannot be solved by a straightforward application of the marching on-in-time (MOT) scheme since the two-sided APSW interpolation functions require the knowledge of unknown “future” ?eld samples during time marching. Causality of the MOT scheme is restored using an extrapolation technique that predicts the future samples from known “past” ones. Unlike the extrapolation techniques developed for MOT schemes that are used in solving time-domain surface integral equations, this scheme trains the extrapolation coef?cients using samples of exponentials with exponents on the complex frequency plane. This increases the stability of the MOT-TD-EFVIE solver signi?cantly, since the temporal behavior of decaying and oscillating electromagnetic modes induced inside the scatterers is very accurately taken into account by this new extrapolation scheme. Numerical results demonstrate that the proposed MOT solver maintains its stability even when applied to analyzing wave interactions on high-contrast scatterers.
关键词： extrapolation,electric ?eld volume integral equation (EFVIE),transient analysis,time-domain analysis,Band-limited interpolation,marching on-in-time (MOT) method
更新于2025-09-23 15:19:57
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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) - Effects of Price Developments on Photovoltaic Panel to Inverter Power Ratios
摘要： A time-domain electric ?eld volume integral equation (TD-EFVIE) solver is proposed for characterizing transient electromagnetic wave interactions on high-contrast dielectric scatterers. The TD-EFVIE is discretized using the Schaubert–Wilton–Glisson (SWG) and approximate prolate spherical wave (APSW) functions in space and time, respectively. The resulting system of equations cannot be solved by a straightforward application of the marching on-in-time (MOT) scheme since the two-sided APSW interpolation functions require the knowledge of unknown “future” ?eld samples during time marching. Causality of the MOT scheme is restored using an extrapolation technique that predicts the future samples from known “past” ones. Unlike the extrapolation techniques developed for MOT schemes that are used in solving time-domain surface integral equations, this scheme trains the extrapolation coef?cients using samples of exponentials with exponents on the complex frequency plane. This increases the stability of the MOT-TD-EFVIE solver signi?cantly, since the temporal behavior of decaying and oscillating electromagnetic modes induced inside the scatterers is very accurately taken into account by this new extrapolation scheme. Numerical results demonstrate that the proposed MOT solver maintains its stability even when applied to analyzing wave interactions on high-contrast scatterers.
关键词： transient analysis,Band-limited interpolation,time-domain analysis,extrapolation,marching on-in-time (MOT) method,electric ?eld volume integral equation (EFVIE)
更新于2025-09-23 15:19:57
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Calculation of electric field gradient in spherical quantum dots
摘要： We have calculated the ground and excited energy states of the quantum dot as a function of the depth of con?ning potential well and radius R. Based on the calculated energies and wave functions, the electric ?eld gradient induced by the non-spherical charge at the impurity is investigated as a function of dot radius and the con?ning potential. For Deuterium dot with spherical con?ning potential, the expectation value of the quadrupole moment operator is carried out. The calculations show that the con?ning potential and the impurity charge have a great in?uence on the electric ?eld gradient and the quadrupole moment. It is found that as the con?ning potential increases, the peak position of the electric ?eld gradient shifts toward smaller dot radii and its amplitude increases with the increase of con?ning potential.
关键词： quadrupole moment,electronic structure,Spherical quantum dot,electric ?eld gradient
更新于2025-09-16 10:30:52
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Design and Analysis of a Ag Rhombus Nanoparticle Film-Coupled Plasmonic Nanostructure
摘要： We design a coupled plasmonic nanostructure, which consists of a Ag rhombus nanoparticle positioned over a silver ?lm, separated by a dielectric spacer layer, and perform numerical analysis by calculating the radiation loss resistance of this nanostructure as the perfect electric conductor metal based on the theory of transmission line modes. Compared with the nanocube or triangular nanodisk ?lm-coupled plasmonic nanostructures introduced in the previous works, a stronger electric ?eld enhancement was achieved in the Ag rhombus nanoparticle ?lm-coupled nanostructure because of the fact that the sharp tip of the rhombus nanoparticle can generate ?eld enhancement at a hot spot. In order to demonstrate that the sharp tip can con?ne the electromagnetic energies strongly, we also have calculated the Purcell factor and the far-?eld directivity of the quantum emitter in the vicinity of this nanostructure.
关键词： Purcell factor,electric ?eld enhancement,plasmonic nanostructure,Ag rhombus nanoparticle,far-?eld directivity
更新于2025-09-11 14:15:04
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An Integrated Photonic Electric-Field Sensor Utilizing a 1 × 2 YBB Mach-Zehnder Interferometric Modulator with a Titanium-Diffused Lithium Niobate Waveguide and a Dipole Patch Antenna
摘要： We studied photonic electric-?eld sensors using a 1 × 2 YBB-MZI modulator composed of two complementary outputs and a 3 dB directional coupler based on the electro-optic e?ect and titanium di?used lithium–niobate optical waveguides. The measured DC switching voltage and extinction ratio at the wavelength 1.3 μm were ~16.6 V and ~14.7 dB, respectively. The minimum detectable ?elds were ~1.12 V/m and ~3.3 V/m, corresponding to the ~22 dB and ~18 dB dynamic ranges of ~10 MHz and 50 MHz, respectively, for an rf power of 20 dBm. The sensor shows an almost linear response to the applied electric-?eld strength within the range of 0.29 V/m to 29.8 V/m.
关键词： titanium di?used optical channel waveguide,lithium–niobate electro-optic e?ect,photonic electric-?eld sensor,Y-fed balanced-bridge Mach-Zehnder interferometer (YBB-MZI)
更新于2025-09-11 14:15:04
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Twin boundary dominated electric field distribution in CdZnTe detectors
摘要： The performance of CdZnTe X/γ-ray detectors is strongly affected by the electric ?eld distribution in terms of charge transport and charge collection. Factors which determine the electric ?eld distribution are not only electric contact, but also intrinsic defects, especially grown-in twin boundaries. Here, the electric ?eld distribution around twin boundaries is investigated in a CdZnTe bicrystal detector with a {111}–{111} twin plane using the Pockels electro-optic effect. The results of laser beam induced current pulses are also obtained by the transient current technique, and we discuss the in?uence of the twin boundary on the electric ?eld evolution. These studies reveal a signi?cant distortion of the electric ?eld, which is attributed to the buildup of space charges at twin boundaries. Also, the position of these space charge regions depends on the polarity of the detector bias. An energy band model based on the formation of an n–n+–n junction across the twin boundary has been established to explain the observed results.
关键词： electric ?eld distribution,Pockels effect,CdZnTe,twin boundary
更新于2025-09-11 14:15:04