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Showing papers on "Equivalent series resistance published in 2007"


Journal ArticleDOI
01 Nov 2007-Carbon
TL;DR: In this article, the performance of carbon onions, nanodiamonds, carbon black and multiwalled nanotubes as electrodes in electrical double layer capacitors with organic electrolyte is described.

662 citations


Journal ArticleDOI
TL;DR: In this article, the series resistance of a monocrystalline industrial screen printed silicon solar cell was measured using luminescence images taken by a thermoelectrically cooled silicon charge coupled device camera.
Abstract: The fast determination of the spatially resolved series resistance of silicon solar cells from luminescence images is demonstrated. Strong lateral variation of the series resistance determined from luminescence images taken on an industrial screen printed silicon solar cell is confirmed qualitatively by a Corescan measurement and quantitatively by comparison with the total series resistance obtained from the terminal characteristics of the cell. Compared to existing techniques that measure the spatially resolved series resistance, luminescence imaging has the advantage that it is nondestructive and orders of magnitude faster. © 2007 American Institute of Physics. DOI: 10.1063/1.2709630 The series resistance of silicon solar cells often exhibits strong lateral variations, particularly in industrial screen printed cells. Experimental techniques to quantify such variations include Corescan, 1 Cello, 2 and imaging techniques based on dark and illuminated infrared lock-in thermography LIT. 3,4 These techniques require data acquisition times between minutes and several hours per solar cell. Electroluminescence EL and photoluminescence PL imaging are very fast characterization tools for silicon solar cells and silicon wafers, with data acquisition times of a few seconds or less per sample. 5,6 Using EL images and PL images taken with external control of the voltage to measure lateral variations of the series resistance in silicon solar cells was proposed in Ref. 7. Some preliminary qualitative results were also reported. 7,8 Here, we demonstrate a quantitative determination of the series resistance and its lateral variation in a monocrystalline industrial screen printed silicon solar cell by luminescence imaging. Photoluminescence images are taken using an 815 nm/25 W laser that is expanded to illuminate the cell area of 12.512.5 cm 2 homogeneously with up to 0.67 Sun equivalent illumination intensity. A thermoelectrically cooled silicon charge coupled device camera is used to capture luminescence images. For the PL images with simultaneous current extraction, two arrays of ten spring loaded contact pins are used to contact the busbars of the cell homogeneously. A commercially available instrument is used for Corescan measurements; illuminated IV curves are measured with a calibrated industrial cell tester. In a simplified case, a solar cell is described as a twodimensional network of parallel nodes, with each node consisting of a series connection of a local resistor Rs,i and a diode. The value of R s,i is given as

248 citations


Journal ArticleDOI
TL;DR: In this paper, the response of single-photon detectors during a photodetection event was modeled, taking into account only the thermal and electrical properties of a superconducting NbN nanowire on a sapphire substrate.
Abstract: We modeled the response of superconducting nanowire single-photon detectors during a photodetection event, taking into consideration only the thermal and electrical properties of a superconducting NbN nanowire on a sapphire substrate. Our calculations suggest that heating which occurs after the formation of a photo-induced resistive barrier is responsible for the generation of a measurable voltage pulse. We compared this numerical result with experimental data of a voltage pulse from a slow device, i.e. large kinetic inductance, and obtained a good fit. Using this electro-thermal model, we estimated the temperature rise and the resistance buildup in the nanowire, and the return current at which the nanowire becomes superconducting again. We also show that the reset time of these photodetectors can be decreased by the addition of a series resistance and provide supporting experimental data. Finally we present preliminary results on a detector latching behavior that can also be explained using the electro-thermal model.

246 citations


Journal ArticleDOI
TL;DR: In this paper, the authors presented a new technique for the evaluation of the parameters of illuminated solar cell with a single diode lumped circuit model and considering the series and shunt resistances.

224 citations


Journal ArticleDOI
TL;DR: In this article, a method based on electroluminescence imaging was proposed to determine mappings of the local series resistance of large area semiconductor devices such as solar cells.
Abstract: This letter introduces a method based on electroluminescence imaging to determine mappings of the local series resistance of large area semiconductor devices such as solar cells. The method combines the local electroluminescence emission Φi(U) and its derivative Φi′(U) with respect to the applied voltage U. The combined analysis of these two quantities yields the local series resistance Rise and proves the physical validity of the used current transport model and thus the physical relevance of the determined Rise value. The method is verified on a monocrystalline silicon solar cell with local shunts and local series resistance problems.

163 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of buffer layers on the performance of polymer photovoltaic devices based on blends of poly3-hexylthiophene and 6,6-phenyl-C-61-buytyric acid methyl ester has been investigated.
Abstract: The influence of anode buffer layers on the performance of polymer photovoltaic devices based on blends of poly3-hexylthiophene and 6,6-phenyl-C-61-buytyric acid methyl ester has been investigated. The buffer layers consist of poly3,4-ethylenedioxythiophene:polystyrenesulfonate PEDOT-PSS doped with different concentrations of mannitol. Improved power conversion efficiency, up to 5.2%, has been observed by reducing the resistance of PEDOT:PSS after doping. One extrapolation method has been developed to exclude the resistance from the connection of the electrodes from the total device resistance. The results confirm that the device improvement is due to the reduction of series resistance of the PEDOT:PSS after the mannitol doping. © 2007 American Institute of Physics. DOI: 10.1063/1.2437703 Organic photovoltaic devices PVs have attracted considerable attention due to their potential for flexible, lightweight, and low-cost applications of solar energy conversion. Recently, the power conversion efficiency PCE of photovoltaic cells around 5% has been realized. 1,2 In addition, through the optimization of the donor/acceptor energy levels, the efficiency up to 10% is expected from recent simulation

151 citations


Journal ArticleDOI
15 Oct 2007
TL;DR: In this paper, a preventive maintenance strategy for the sensorless condition monitoring of inverter dc-link aluminum electrolytic capacitors based on equivalent series resistance (ESR) and capacitance C estimation is proposed.
Abstract: A new preventive maintenance strategy for the sensorless condition monitoring of inverter dc-link aluminum electrolytic capacitors based on equivalent series resistance (ESR) and capacitance C estimation is proposed. The main concept of the proposed method is to estimate the ESR and C of the capacitor, using the inverter whenever the motor is stopped. The parameters are estimated from the dc-link voltage and stator current measurements available in the inverter with the switched dc-link voltage applied to the motor stator winding. The temperature of the capacitor can also be estimated under thermal equilibrium based on the stator resistance estimate to take the influence of temperature variation into account. An experimental study on a 250-W permanent magnet synchronous motor performed under accelerated capacitor degradation is presented to verify the proposed technique. It is shown that the proposed method provides a reliable and sensitive indication of capacitor aging without additional hardware requirements for reliable, efficient, and safe operation of the inverter and driven process.

147 citations


Journal ArticleDOI
TL;DR: In this paper, the authors proposed to add a thin sputtered Al2O3 layer to nominal electron-only, hole-only and bipolar organic diodes, which acts as a current limiting series resistance.
Abstract: Resistive switching in nonvolatile, two terminal organic memories can be due to the presence of a native oxide layer at an aluminum electrode. Reproducible solid state memories can be realized by deliberately adding a thin sputtered Al2O3 layer to nominal electron-only, hole-only, and bipolar organic diodes. Before memory operation, the devices have to be formed at an electric field of 109V∕m, corresponding to soft breakdown of Al2O3. After forming, the structures show pronounced negative differential resistance and the local maximum in the current scales with the thickness of the oxide layer. The polymer acts as a current limiting series resistance.

132 citations


Journal ArticleDOI
Abstract: This paper examines the impact of an important geometrical parameter of FinFET devices, namely the fin width. From static and low-frequency measurements on n-FinFETs ( I – V , C – V and 1/ f noise), transistor Figures of Merit in the near-threshold region (like threshold voltage, subthreshold slope, and drain induced barrier lowering); linear region (mobility, series resistance, 1/ f noise) and saturation region (normalized transconductance, early voltage) are analyzed as a function of fin width. In the near-threshold region, fin width is seen to strongly impact the coupling between the back and front gates, while in the above threshold region, the most important impact of fin width is on the parasitic source/drain resistance, which affects different strong inversion parameters to different extents. With the help of analytical expressions, the impact of series resistance on these device parameters is studied, and the contribution from series resistance is de-embedded, enabling extraction of intrinsic device parameters. Significant differences are observed between the intrinsic and extrinsic parameters, especially for short and narrow devices, which also underlines the need for accounting for series resistance effects at every stage of FinFET characterization.

89 citations


Journal ArticleDOI
TL;DR: In this article, the performance of the GaN IMPATT diodes in the terahertz regime was investigated using a modified double iterative simulation technique and the effect of photo-illumination on the devices was investigated.
Abstract: The prospects of wurtzite phase single-drift-region (SDR), flat and single-low-high-low (SLHL) type GaN IMPATT devices as terahertz sources are studied through a simulation experiment. The study indicates that GaN IMPATT diodes are capable of generating high RF power (at least 2.5 W) at around 1.45 THz with high efficiency (17–20%). The superior electronic properties of GaN make this a promising candidate for IMPATT operation in the THz regime, unapproachable by conventional Si, GaAs and InP based IMPATT diodes. The effect of parasitic series resistance on the THz performance of the device is further simulated. It is interesting to note that the presence of a charge bump in a flatly doped SDR structure reduces the value of parasitic series resistance by 22%. The effects of photo- illumination on the devices are also investigated using a modified double iterative simulation technique. Under photo-illumination (i) the negative conductance and (ii) the negative resistance of the devices (both flat and SLHL) decrease, while the frequency of operation and the device quality factor shift upwards. However, the upward shift in operating frequency is found to be more (~16 GHz) in the case of the SLHL SDR IMPATT device. The study indicates that GaN IMPATT is a promising opto-sensitive high power THz source.

88 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe the design and testing of organic electrolyte systems that extend the low temperature operational limit of double-layer capacitors beyond that of typical commercially available components.

Journal ArticleDOI
Petru Andrei1, L. L. Fields1, Jim P. Zheng1, Yi Cheng1, Peng Xiong1 
TL;DR: In this paper, the saturation of the output curves (drain current versus drain-to-source voltage) in air is not due to channel pinch-off, but rather to saturation of reversed-biased current of the Schottky-like contact.
Abstract: Individual tin dioxide nanobelts were used to fabricate field-effect transistor (FET) devices. The output characteristics of these devices have been measured under various ambient conditions, and modeled with a modified drift-diffusion model in which quantum mechanical effects are taken into consideration using the density-gradient model. It is shown that the saturation of the output curves (drain current versus drain-to-source voltage) in air is not due to channel pinch-off, but rather to the saturation of the reversed-biased current of the Schottky-like contact. In this case the source and drain contacts behave like rectifying diodes and can be modeled as two Schottky diodes connected back-to-back with a series resistance from the nanobelt separating the diodes. In the presence of hydrogen the rectifying behavior of the two contacts disappears and the current through the device is limited by the resistance of the nanobelt that can be modulated efficiently by using a gate electrode.

Journal ArticleDOI
Ansgar Mette1, D. Pysch1, Gernot Emanuel1, D. Erath1, Ralf Preu1, Stefan W. Glunz1 
TL;DR: In this article, the authors presented the results of a detailed series resistance characterization of silicon solar cells with screen-printed front contacts using hotmelt silver paste, and applied the hot-melt technology energy conversion efficiencies up to 18·0% on monocrystalline wafers.
Abstract: This work presents the results of a detailed series resistance characterization of silicon solar cells with screen-printed front contacts using hotmelt silver paste. Applying the hotmelt technology energy conversion efficiencies up to 18·0% on monocrystalline wafers with a size of 12·5 cm × 12·5 cm have been achieved, an increase of 0·3% absolute compared to cells with conventional screen-printed contacts. This is mainly due to the reduction in the finger resistance to values as low as 14 Ω/m, which reduces the series resistance of the solar cell significantly. To retrieve the lumped series resistance as accurately as possible under the operating condition, different determination methods have been analyzed. Methods under consideration were fitting of the two-diode equation function to a dark IV-curve, integration of the area A under an IV-curve, comparison of a jsc–Voc with a one-sun IV-curve, comparison of the jsc and Voc points of a shaded curve with the one-sun IV-curve as well as comparison of a dark IV-curve with a one-sun IV-curve, and comparison of IV-curves measured at different light intensities. The performed investigations have shown that the latter four methods all resulted in reliable series resistance values. Copyright © 2007 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: In this paper, the experimental method to measure the current spreading length in GaN-based light emitting diodes (LEDs) based on a one-dimensional current-distribution model neglecting vertical series resistance of the LEDs is presented.
Abstract: The authors report on the experimental method to measure the current spreading length in GaN-based light emitting diodes (LEDs) based on a one-dimensional current-distribution model neglecting vertical series resistance of the LEDs. It is clearly shown that the measured current spreading length is in good agreement with the calculated results, exhibiting a strong dependence on the injected current density (or forward bias voltage). LEDs fabricated with hybrid p-type reflectors by using the proposed design rule and measured current spreading lengths show enhancement of the output power by 10% as compared to LEDs made with standard reflectors.

Patent
16 Nov 2007
TL;DR: In this article, a resistance change type memory (100) is used to transits between a plurality of resistance states with an electric pulse of the same polarity, where the node potential does not exceed a second voltage level even if the electric pulse application device (50) outputs a first electric pulse.
Abstract: A resistance change type memory (100) uses a resistance change type element (22) which transits between a plurality of resistance states with an electric pulse of the same polarity The resistance change type memory includes a series resistance setting device (10) which can set a resistance value of a series current path and a parallel resistance setting device (30) which can set a resistance value of a parallel current path as follows That is, after the resistance change type element (22) has changed to a high resistance state, the node potential does not exceed a second voltage level even if an electric pulse application device (50) outputs a first electric pulse and after the resistance change type element (22) has changed to a low resistance state, the node potential does not exceed a first second voltage level even if the electric pulse application device (50) outputs a second electric pulse

Journal ArticleDOI
TL;DR: Pentacene based junctions with Al on both p-Si(1 0 0) and indium tin oxide (ITO) substrates have been analyzed using impedance spectroscopy (100 Hz-20 MHz) and dc-current versus voltage measurements.
Abstract: Pentacene based junctions with Al on both p-Si(1 0 0) and indium tin oxide (ITO) substrates have been analysed using impedance spectroscopy (100 Hz–20 MHz) and dc-current versus voltage measurements. Conduction mechanisms match well with the space charge limited current model with exponential trap charge distributions. Impedance studies reveal the Schottky behaviour for both the devices. The differences between p-Si/pentacene/Al and ITO/pentacene/Al devices have been explained by modelling equivalent circuits, with one and two RC elements, respectively. The switch-over field from ohmic conduction to space charge limited conduction, charge concentration as a function of voltage and bias dependent series resistance have been estimated for both the cases.

01 Jan 2007
TL;DR: The tantalum capacitors have been on the market for more than half a century as mentioned in this paper and they still continue to grow, especially, relatively new types of Ta capacitors likeTa capacitors with conductive polymer cathode.
Abstract: Despite constant competition from aluminum and ceramic capacitors, tantalum (Ta) capacitors have been on the market for more than half a century. They still continue to grow, especially, relatively new types of Ta capacitors like Ta capacitors with conductive polymer cathode. The major parameters, which keep Ta capacitors on the market and make them attractive for use in electronic devices, are high volumetric efficiency (CV/cc), low Equivalent Series Resistance (ESR) and Equivalent Series Inductance (ESL), highly stable characteristics with respect to voltage and temperature, and high stability over long periods of time (i.e., high reliability).

Journal ArticleDOI
TL;DR: In this article, the authors applied simulations to study current spreading and heat transfer in blue III-nitride light-emitting diodes with the focus on self-heating and its effect on the device characteristics.
Abstract: We have applied simulations to study current the spreading and heat transfer in blue III-nitride light-emitting diodes (LEDs) with the focus on self-heating and its effect on the device characteristics. A conventional planar design of an LED die is considered for the heat sink through a sapphire substrate. The computations predict a great current crowding at the contact electrode edges, resulting in a non-uniform temperature distribution over the die. The thermal effect on the current-voltage characteristic, output optical power, and series resistance of the diode is analyzed and the theoretical predictions are compared with available observations. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Proceedings ArticleDOI
04 Jun 2007
TL;DR: In this article, the authors propose a methodology to estimate junction temperature of high power LEDs by discarding the influence of the intrinsic series resistance of the LED electric model in 1-V curve, avoiding, as a consequence measurement errors.
Abstract: The understanding of the thermal properties of a high power LEDs is essential in order to achieve the highest optical performance of the device without sacrificing its reliability. In addition to that, the good thermal management is also a key factor to avoid thermal induced variation of the photometric / colorimetric properties of power LEDs, such as variation of relative light output or the spectrum. This paper proposes a methodology to estimate junction temperature of high power LEDs. This method allows discarding the influence of the intrinsic series resistance of the LED electric model in 1-V curve, avoiding, as a consequence measurement errors.

Journal ArticleDOI
TL;DR: In this article, the gamma irradiation effects on interface state density and series resistance determined from capacitance-voltage (C-V) and conductance voltage (GV) characteristics in Au/SnO2/n-Si (MOS) structures prepared at various SnO2 layer thicknesses by spray deposition technique.
Abstract: We report the first investigation of the gamma irradiation effects on interface state density and series resistance determined from capacitance–voltage (C–V) and conductance–voltage (G–V) characteristics in Au/SnO2/n-Si (MOS) structures prepared at various SnO2 layer thicknesses by spray deposition technique. It was fabricated three samples depending on deposition time. The samples were irradiated using a 60Co γ-ray source irradiation with the total dose range was 0–500 kGy at room temperature. The C–V and G–V measurements of the samples were performed at high frequency (500 kHz) at room temperature before and after irradiation. The measurement capacitance and conductance are corrected for series resistance. The thicknesses of SnO2 films obtained from the measurement of the oxide capacitance in the accumulation region for MOS Schottky diodes were 19, 52, 191 A, for D1, D2 and D3 samples, respectively. It has been seen that the value of the series resistance Rs of samples D1 (50 Ω), D2 (66 Ω) and D3 (157 Ω) increases with increasing the oxide layer thickness and increases from 50 Ω to 62.7 Ω with increasing irradiation dose. The single frequency method of Hill-Coleman was used to determine the interface state density (Dit).

Journal ArticleDOI
TL;DR: In this paper, a new method of extracting the MOSFET series resistance is proposed, which requires only simple dc measurements on a single test device, without requiring quantities such as gate-oxide thickness, physical gate length, or effective channel length.
Abstract: A new method of extracting the MOSFET series resistance is proposed. This method requires only simple dc measurements on a single test device. Experimental demonstration is presented, without requiring quantities such as gate-oxide thickness, physical gate length, or effective channel length. The merit of the method stems from the specifically arranged bias conditions in which the channel carrier mobility remains constant for high vertical electric fields. It is this unique property which makes the proposed method suitable for short-channel devices.

Journal ArticleDOI
TL;DR: An electric double layer capacitor (EDLC) was fabricated with the addition of carbon nanotubes (CNTs) to the polarizable electrodes to act as a conducting material as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, the frequency dependence of capacitance and conductance of SiO2/n-Si metal-insulator-semiconductor (MOS) structures with thermal growth oxide layer has been investigated taking into account the effect of the series resistance and interface states.
Abstract: Au/SiO2/n-Si metal–insulator-semiconductor (MOS) structures with thermal growth oxide layer have been fabricated. The frequency dependence of capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics of these structures have been investigated taking into account the effect of the series resistance and interface states. The C–V and G/ω–V measurements have been carried out in the frequency range of 1 kHz–1 MHz at room temperature. The frequency dispersion in capacitance and conductance can be interpreted in terms of the interface states density (Nss) and series resistance values (Rs). The interface states can follow the ac signal and yield an excess capacitance especially at low frequencies. The values of measured C and G/ω decrease in depletion region with increasing frequencies especially in low frequencies due to a continuous density distribution of interface states. The C–V plots exhibit anomalous peaks due to the Nss and Rs effect. It has been experimentally found that the peak positions in the C–V plot shift towards positive voltages and the peak value of the capacitance decreases with increasing frequency. The effect of series resistance on the capacitance is found appreciable at high frequencies due to the interface state capacitance decreasing with increasing frequency. In addition, the high-frequency capacitance (Cm) and conductance (Gm/ω) values measured under both reverse and forward bias were corrected for the effect of series resistance to obtain the real diode capacitance. Experimental results show that the locations of interface states between Si/SiO2 and series resistance have a significant effect on electrical characteristics of MOS structures.

Journal ArticleDOI
TL;DR: In this paper, the current spreading length of GaN-based light-emitting diodes (LEDs) was measured and analyzed for practical device design based on Thompson's and Guo's models, which are categorized according to vertical series resistance.
Abstract: Based on the proposed experimental method, the current spreading length of GaN-based light-emitting diodes (LEDs) was measured and analyzed for practical device design. In this study, Thompson's and Guo's models, which are categorized according to vertical series resistance (in particular, p-type contact resistance), were used to extract device parameters. It was shown that the measured current spreading length strongly depends on the injected current density. For LEDs fabricated with low-resistance p-type contacts, this behavior could be explained in terms of the accelerated current crowding with higher current densities occurring as a result of the reduced voltage drop across the junction, which is in good agreement with Thompson's relation. However, for LEDs fabricated with high-resistance p-contacts, unlike Guo's prediction, the measured current spreading length also showed a strong dependence on the injected current density. This was attributed to thermal heating at the p-contact, resulting in the reduction of the voltage drop across the p-contact and so junction voltage, which is also in agreement with Thompson's model. Based on the measured parameters and the design rule, efficient p-type reflectors, namely, hybrid reflectors were designed. Compared with conventional ones, LEDs fabricated with the hybrid reflectors exhibited better output power at a reasonable forward voltage, indicating that the proposed method is effective in understanding the actual current spreading and hence the practical design of high-efficiency LEDs.

Patent
09 Apr 2007
TL;DR: In this article, the authors proposed a parallel combination rule to decrease the parasitic resistance of an inductor by placing several inductors in parallel, which can be used to increase the mutual inductance between these inductors to a value near that of the original inductance value.
Abstract: Placing inductors or resistors in parallel causes the combined value of inductance or resistance to decrease according to the parallel combination rule. This invention decreases the parasitic resistance of an inductor by placing several inductors in parallel. Furthermore, by careful placement of these inductors, the mutual inductance between these inductors can be used to increase the equivalent inductance value to a value near that of the original inductance value of a single inductor. Thus, it is possible to create an inductance with a much lower value of parasitic resistance. This invention allows the formation of high Q inductors and would be beneficial in any circuit design requiring inductances. Another aspect of this invention is that the coils can be partitioned to minimize eddy current losses. This invention can easily be implemented in a planar technology. Simulations of several tank circuits indicate that the power dissipation can be reduced 3 to 4 times when compared to conventional techniques.

Patent
09 Oct 2007
TL;DR: In this article, an asymmetric field effect transistor structure (200a-c) and a method of forming the structure in which both series resistance in the source region (204, 304) (Rs) and gate (210, 310) to drain ((205, 305) capacitance (Cgd) are reduced in order to provide optimal performance (i.e., to provide improved drive current with minimal circuit delay).
Abstract: Disclosed are embodiments of an asymmetric field effect transistor structure (200a-c) and a method of forming the structure in which both series resistance in the source region (204, 304) (Rs) and gate (210, 310) to drain ((205, 305) capacitance (Cgd) are reduced in order to provide optimal performance (i.e., to provide improved drive current with minimal circuit delay) Specifically, different heights (214, 215) of the source (204) and drain regions (205) and/or different distances (351, 352) between the source (304) and drain regions (305) and the gate (210, 310) are tailored to minimize series resistance in the source region (204, 305) (i.e., in order to ensure that series resistance is less than a predetermined resistance value) and in order to simultaneously to minimize gate (210, 310) to drain (205, 305) capacitance (i.e., in order to simultaneously ensure that gate ( 210, 310) to drain (205, 305) capacitance is less than a predetermined capacitance value).

Journal ArticleDOI
TL;DR: In this paper, the authors used Cheung's functions to calculate diode parameters such as ideality factor, series resistance, and barrier height of the Schottky diode and showed that the diode has a metal-SiO2 oxide layer plus organic layer-semiconductor configuration.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the current-voltage characteristics and inhomogeneous-barrier analysis of a Si/Al diode with an interfacial layer formed during surface preparation and determined the electronic parameters such as barrier height, ideality factor and series resistance of the device using Cheung's method.
Abstract: The current–voltage characteristics and inhomogeneous-barrier analysis of ddq/p-type Si/Al diode with interfacial layer have been investigated by current–voltage measurements. The device behaves like an Schottky contact at low voltages. The obtained ideality factor n value is higher than unit. The current–voltage characteristics of the diode show a nonideal behavior. This behavior arises from the series resistance and the presence of an interfacial layer formed during the surface preparation. The electronic parameters such as barrier height, ideality factor and series resistance of the device were determined using Cheung's method. The effect of the series resistance for the device was not ignored and the obtained values are lower than the equivalent values obtained previously without considering effect of the presence of interfacial layer. A decrease in φ B and an increase in the ideality factor with decreasing temperature were observed and this case was explained on the basis of a thermoionic mechanism with Gaussian distribution. The obtained standard deviation, which is a measure of the barrier homogeneity, indicates the presence of the interface inhomogeneities.

Patent
29 Aug 2007
TL;DR: In this paper, a multilayer capacitor is mounted on a surface of a substrate by using a solder, and a current path becomes two narrow paths between the first leadout portion 5 and second lead-out portion 6, and an electrode pattern 15 of the substrate 13 and can be made long in length by varying the thickness (t) of the insulating layers 11 and 12 and then increasing the height of the solder.
Abstract: PROBLEM TO BE SOLVED: To provide a multilayer capacitor which can be made high in equivalent series resistance (ESR) without varying equivalent series inductance (ESL) so much, and a capacitor mounting substrate. SOLUTION: Insulating layers 11 and 12 are formed on surfaces of terminal electrodes 7 and 8 respectively to cover exposed surface center portions of first and second lead-out portions 5 and 6 disposed one over the other in a laminating direction (x) with the terminal electrodes 7 and 8 interposed therebetween, so when a plurality of such multilayer capacitors 10 are mounted on a surface of a substrate 13 by using a solder, a current path becomes two narrow paths between the first lead-out portion 5 and second lead-out portion 6, and an electrode pattern 15 of the substrate 13 and can be made long in length by varying the thickness (t) of the insulating layers 11 and 12 and then increasing the height of the solder, and the equivalent series resistance (ESR) can be made high without varying the equivalent series inductance (ESL) so much. COPYRIGHT: (C)2009,JPO&INPIT

Journal ArticleDOI
TL;DR: In this article, the authors presented passive network properties of individual multi-walled carbon nanotubes (MWNTs) up to 110 GHz measured at room temperature and extracted frequency-dependent electric properties of the MWNTs using an equivalent R-L-C circuit model.
Abstract: Metallic carbon nanotubes (CNTs) are promising as transmission lines or interconnects in radio-frequency nanoelectric circuits. This paper presents passive network properties of individual multi-walled carbon nanotubes (MWNTs) up to 110 GHz measured at room temperature. From the S-parameter data, frequency-dependent electric properties of the MWNT were extracted using an equivalent R-L-C circuit model. The ac impedance of the MWNT decreases significantly with increasing frequency, as predicted by earlier theoretical work. In particular, the equivalent resistance decreases a few hundred times. Our findings show that MWNTs can carry high-frequency currents much better than dc.