Current-voltage Techniques Research Articles

Low bias charge transport in DNA.

The low-bias current-voltage technique was utilized to study charge transport in single-stranded DNA (ssDNA), assessing the method's effectiveness for future studies aimed at estimating the degree of mutation or DNA damage. In the paper, we showed that charge carrier transfer processes in ssDNA can be precisely monitored using low-bias currents. We used negative differential resistance and the Fowler-Nordheim model to differentiate the charge transport mechanisms observed in a device composed of gold electrode-thiol-ssDNA junctions. It was possible to distinguish the processes at the two junctions (Au/thiol and thiol/DNA) due to their distinct current-voltage characteristics. We observed positive charge carrier tunneling, which we attribute to oxidation and reduction processes in the nucleobases of the ssDNA. Our results suggest that even minor changes in DNA chains can be accurately detected using the described methodology.

Suppression of irradiation effect on electrical properties of silicon diodes by iron in p-silicon

Radiation-hardness of silicon (Si) has been the subject of interest due to the damage of the material-based detectors during and after operation. In this work, the effects of 4 MeV proton-irradiation on the electrical properties of devices fabricated on undoped and Fe-doped p-Si were investigated using current-voltage (I-V) and capacitance-voltage (C-V) techniques. A decrease in current and capacitance is less pronounced and the conduction mechanism remains unchanged on Fe-doped p-Si diode after proton-irradiation. This insignificant change of electrical parameters of the Fe-doped diode after proton-irradiation indicates the suppression of the radiation effect by Fe in Si. The electrical properties of the diode are less dependent on incident radiation, because of the possible prevention of further dislodgement of atoms by incident radiation. As a result, the material becomes resistant to radiation damage, making the electrical properties of the diode independent of incident radiation due to Fe atoms in Si. As a result of the ohmic behaviour displayed by the Fe-doped Si diode, it is possible that in Si, Fe is responsible for generation-recombination (g-r) centres, which are defect levels positioned at the middle of the energy gap of Si. The possibility of these defects being responsible for the suppression of the radiation effect is explained in this work, making Fe a promising dopant to improve the radiation-hardness of Si.

Structural and electronic characterization of silicon based MIS contact by xanthene dye molecules (Erythrosine B)

The effect of erythrosine B (ERY) organic material as an interface layer on the electronic characteristics of the Al/p-Si junction is examined in the present work. AFM, NMR, UV–Vis and FTIR measurements have been conducted on the ERY dye molecule. The ERY film on the surface of the substrate is coated with nanoparticles, according to the surface analysis performed using the AFM technique. The basic diode parameters of Al/p-Si and Al/ERY/p-Si junctions were measured by utilizing current-voltage (I–V) and capacitance-voltage (C-V) techniques. The junctions with and without organic interfacial layers were found to have ideality factors of 1.931 and 1.925, respectively. For MS and MIS contacts, the estimated values of barrier height were 0.592 eV and 0.937 eV, respectively. Additionally, the series resistances for the MS and MIS structures by utilizing Norde function, were determined to be 0.14 kΩ and 322.85 kΩ, respectively. In addition, the reverse bias 1/C2-V characteristics were used to analyze the barrier height values and compare the findings to those from I-V method. The experimental findings demonstrated that the Al/ERY/p-Si MIS diode has a barrier height that is remarkably greater than that of the reference Al/p-Si junction. Placement of the ERY dye interlayer between a metal and a semiconductor could enhance and regulate the performance and characteristic of these types of junctions.

Carmoisine azo dye-modified Al/p-Si junction

This study investigates the impact of a Carmoisine azo dye layer on electronic transport at the p-silicon/Al interface. The morphology of the Carmoisine azo layer is characterized using atomic force microscopy (AFM). Various spectroscopic measurements, including nuclear magnetic resonance (NMR), ultraviolet–visible (UV–Vis), and Fourier transform infrared (FTIR) spectroscopy, are employed to analyze the Carmoisine dye molecule. The direct and indirect band gap values of the Carmoisine dye molecule, prepared in methanol solvent, are determined to be Eg,1 = 2.15 eV and 2.06 eV (D band) and Eg,2 = 3.54 eV and 3.35 eV (C band), respectively. Results indicate that the Carmoisine film on a glass slide consists of non-homogeneous microstructures, with a surface roughness of 16.76 nm. A spin coater is used to form an Al/Carmoisine/p-Si device, which is a cost-effective and readily scalable approach for creating semiconductor films. The basic contact parameters of the Al/p-Si and Al/Carmoisine/p-Si contacts are measured using current-voltage (IV) and capacitance-voltage (CV) techniques. The Al/Carmoisine/p-Si device exhibits good rectifying behaviour, with an ideality factor value of 1.547, indicating that the Carmoisine azo dye used as the interface material enhances the junction's performance and reduces the ideality factor. Barrier height (BH) parameters are calculated to be 0.770 eV, 0.733 eV, and 0.799 eV using the lnI-V, Cheung, and Norde techniques, respectively. The interfacial dipole created by passivation of the film causes the Carmoisine interlayer to raise the BH, resulting in an improved interface region for Al/p-Si structures. The extracted interfacial level concentration (Nss) of the Al/Carmoisine/p-Si junction is lower than that of the Al/p-Si contact, indicating that the Carmoisine dye molecule reduces the Nss value. Furthermore, the reverse bias 1/C2-V characteristic is employed to analyze the barrier height values and compare the findings to those from the IV method. The results show that the thin Carmoisine azo dye layer decreases leakage current and defect-trapped charge density, enhancing the reliability and performance of the devices. This study contributes a new organic electronic material, Carmoisine dye, to the literature on semiconductor devices.

Examination of Structural and Electrical Properties of CuO‐Doped CdO Nanocomposites Produced by the Hydrothermal Method

AbstractIn this study, pure CdO and CdO‐CuO nanopowders with different dopant concentrations are synthesized by the hydrothermal method. Structural properties of the nanopowders are characterized by X‐ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR), morphological properties and elemental analyses are characterized by Field Emission Scanning Electron Microscopy (FESEM), optical properties are characterized by UV–vis spectroscopy, and electrical properties are characterized by the current–voltage technique. XRD data show that nanopowders are polycrystalline and crystallinity decreases with the doping concentration. In the analysis of FESEM images, it can be concluded that the morphology of the particles is shaped as needle‐like, spherical‐like, and randomly oriented nanorods forms from the cube form. Also, by joining those nanorods, spherical‐like microstructures occur, and while the dopant concentration increases, echinus‐like forms are obtained. The energy bandgap of the nanopowders decreases with an increased dopant concentration of CuO. It is observed that the dopant concentration of CuO also changes the electrical properties.

Half and full solar cell efficiency binning by deep learning on electroluminescence images

AbstractEnd‐of‐line characterization of solar cells is necessary to filter out defective cells and bin cells to avoid power mismatch loss in photovoltaic modules. Current–voltage testers, used by almost any photovoltaic company and research laboratory, are costly to maintain and to adapt to recent and predicted morphological changes in solar cells: larger and thinner wafers, half or shingled cells, a wide range of busbar layouts, and more. In this study, we challenge this fundamental technique and propose to bin solar cells and detect defective cells based on a deep learning analysis of their electroluminescence images. The use of electroluminescence imaging addresses the above‐mentioned limitations of the current–voltage technique, as well as allowing faster measurements as it avoids any capacitance effects. By introducing LumiNet, a convolutional neural network end‐to‐end framework, solar cell efficiency bins can be accurately predicted from electroluminescence imaging with a mean error similar to that obtained by current–voltage measurements. The proposed framework is validated on several state‐of‐the‐art mono‐crystalline silicon solar cell structures. We show that photovoltaic modules fabricated using the proposed method would have similar mismatch loss as the traditional current–voltage binning. We then demonstrate the method on half‐cut silicon solar cells. Predicting the half‐cut cell efficiencies, from the deep learning framework, enables manufacturers to assess post‐cutting damages and reassess their binning strategy before module assembly. Furthermore, the deep learning framework is shown to work well even on datasets that have not been previously seen. The trained deep learning LumiNet models' structure and weight are shared with the community to accelerate the adaptation of deep learning for luminescence image analysis in the photovoltaic industry.

Graphene oxide synthesized from zinc-carbon battery waste using a new oxidation process assisted sonication: Electrochemical properties

The purpose of this paper is to fabricate graphene oxide (GO) from carbon rods of spent (ZnC) batteries using a new optimized approach in electrochemical applications. The proposed method-based sonication for the recycling of carbon rods was adopted as a fast and economical process via a less aggressive pathway. The energy reaction time and explosion problems were avoided by the proposed protocol. The waste graphite powder (carbon rods) and the powder produced by the developed method-based sonication (SGO) were characterized by UV–Visible, XRD, FTIR and SEM. The electrochemical performance of the prepared SGO was evaluated by cyclic voltammetry (CV) and current-voltage (I–V) techniques. The results revealed that SGO has a higher electrocatalytic property compared to the graphene oxide by the standard Hummers method (HGO).

Characterization of magnetic Czochralski silicon devices with aluminium oxide field insulator: effect of oxygen precursor on electrical properties and radiation hardness

Aluminium oxide (Al2O3) has been proposed as an alternative to thermal silicon dioxide (SiO2) as field insulator and surface passivation for silicon detectors, where it could substitute p-stop/p-spray insulation implants between pixels due to its negative oxide charge, and enable capacitive coupling of segments by means of its higher dielectric constant.Al2O3 is commonly grown by atomic layer deposition (ALD), which allows the deposition of thin layers with excellent precision.In this work, we report the electrical characterization of single pad detectors (diodes) and MOS capacitors fabricated on magnetic Czochralski silicon substrates and using Al2O3 as field insulator. Devices are studied by capacitance-voltage, current-voltage, and transient current technique measurements. We evaluate the influence of the oxygen precursors in the ALD process, as well as the effect of gamma irradiation, on the properties of these devices. We observe that leakage currents in diodes before the onset of breakdown are low for all studied ALD processes. Charge collection as measured by transient current technique (TCT) is also independent of the choice of oxygen precursor. The Al2O3 films deposited with O3 possess a higher negative oxide charge than films deposited by H2O, However, in diodes a higher oxide charge is linked to earlier breakdown, as has been predicted by simulation studies. A combination of H2and O3 precursors results in a good compromise between the beneficial properties provided by the respective individual precursors.

Electrical properties of 3 MeV proton irradiated silicon Schottky diodes

This work presents the effects of proton irradiations on the electrical properties of n-silicon-based Schottky diodes. A change in electrical properties of the diodes due to 3 MeV proton irradiation to the fluence of 1017 ion cm−2 was investigated by current-voltage (I-V) and capacitance-voltage (C-V) techniques. A drastic decrease in forward current by a factor of 103 indicates a reduction of free injected effective carrier density in the space charge region. This reduction in the density is observed by a decrease in rectification ratio after proton irradiation. The results in general indicate that proton induced defects are responsible for the recombination/compensation of charge carriers resulting in an increase in the resistivity of the material. An increase in the resistivity is confirmed by high series resistance and low doping density evaluated on the irradiated diode. A change in dominated diode conduction mechanism due to irradiation presented here is of technological importance. Furthermore, the results presented here would, certainly, contribute to an ongoing study on the induced damage by radiation in silicon.

Impact of Lanthanum-Doping on the Physical and Electrical Properties of Cobalt Ferrites

Cobalt ferrites have attracted extraordinary attention due to their high coercivity, chemical stability, and mechanical hardness. Lanthanum doped-cobalt ferrites having chemical formula CoLaxFe2-xO4 with composition x = (0.00, 0.015, 0.045, 0.060) were synthesized by chemical co-precipitation method. The prepared samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and current-voltage (I-V) technique. The structure of the crystal was analyzed by X-ray diffraction. The crystallite size of nanoparticles was examined in the range of 21–25 nm, and a fluctuating trend was found with the inclusion of La3+ cations. The X-ray diffraction patterns verify the contraction of lattice constant and unit cell volume with the substitution of La3+ cations except for the concentration of x = 0.060. Lattice constant was in the range of 8.34 A–8.41 A while unit volume cell was in the range of 580 A3–596 A3. The resistivity of all samples was calculated by the application of two probes I-V technique. The maximum resistivity of the order of 81.129 × 105 Ω cm was found for the concentration of x = 0.060 at 723 K which makes it useful for high-frequency gimmicks applications. The resistivity and drift mobility were found inversely related to each other. The inverse relation low-frequency absorption band and high-frequency absorption bands were analyzed by Fourier-transform infrared spectroscopy technique.

Observation of mixed types of energy gaps in some II–VI semiconductors nanostructured films: towards enhanced solar cell performance

All solid-state quantum dots embedded multi-junction solar cell with the device structure of (Glass/ITO/ZnTe/ZnS/CdS/Au) is achieved to boost the photo-conversion efficiency by incorporating inner layer of ZnS and by effectively utilizing the entire solar spectrum. Electron beam evaporation was used to deposit the three semiconductor materials ZnTe, ZnS and CdS thin films. The optical properties and energy bandgap of each of the three materials were determined using ellipsometric measurements. The device performance was investigated using current voltage (J–V) techniques at room temperature and under AM1.5 illumination conditions. In this study, we showed that the optical energy gaps of some nanoscale binary semiconductor compounds from II–VI family exhibit both direct and indirect types of optical energy bandgap and there is a giant increase in their direct values.

Evaluation of structural, optical, dielectric, electrical, and magnetic properties of Ce3+ doped Cu0.5Cd0.25Co0.25Fe2-xO4 spinel nano-ferrites

Rare earth cerium (Ce3+) doped Cu0.5Cd0.25Co0.25CexFe2-x O4 (x = 0, 0.0125, 0.025, 0.0375, 0.05) spinel ferrites nanoparticles were synthesized via co-precipitation technique. XRD, FT-IR, UV-VIS, VSM, LCR and current-voltage measurement techniques were utilized to investigate the structural parameters, metal stretching vibrations, indirect energy band gap, magnetic parameters and electrical behavior of synthesized ferrite powders respectively. The XRD patterns confirmed the remarkable reduction in crystallites size, cell volume and lattice constant while both densities (ρx,ρbulk) tends to increase with rise in Ce3+contents(x). The indirect energy band gaps (Eg) and the DC electrical resistivities were found in decreasing order from 3.48 to 2.50 eV and 9.902×107 to 0.142×107(ohm-cm) respectively at room temperature (303 K) with Ce3+ doping concentration. LCR meter inveterate that the dielectric constant had declining, and ac conductivity had growing trend at fix value of cerium concentration with rise of frequency from 8 Hz to 8 MHz. The soft magnetic properties can be significantly improved by the small amount of Ce3+ ion doping (x = 0.0375) with an increase of the saturation magnetization (Ms), and retentivity (Mr).

Micro-Tubular Solid Oxide Fuel Cell Polarization and Impedance Variation With Thin Porous Samarium-Doped Ceria and Gadolinium-Doped Ceria Buffer Layer Thickness

Abstract Porous buffer layers for anode-supported solid oxide fuel cells (SOFCs) have been investigated for many years with different thicknesses of the buffer layer in each study. In this work, micro-tubular SOFCs having samarium-doped ceria (SDC) and gadolinium-doped ceria (GDC) buffer layers are compared using the current–voltage technique, electrochemical impedance spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The thickness of the porous SDC and GDC buffer layer is investigated systematically with the thickness varying between 0.3 and 2.0 μm. The power density varies between 212 and 1004 mW/cm2 for samples having different SDC buffer layer thickness. Comparable changes occur for the SOFCs with a GDC buffer layer, but less variation in polarization losses resulted. Variation in electrochemical performance varies due to changes in ohmic resistance, cathode activation polarization, and interfacial reactions between the cathode and electrolyte materials.

Comparison of Maximum Power Point Tracking Techniques on Photovoltaic Panels

In this study, a simulation is performed in Matlab/Simulink to evaluate the energy production performance of the perturb & observe, incremental conductance, short circuit current and open circuit voltage techniques. In order to evaluate the performance of the techniques, they are tested under constant temperature and irradiation conditions, as well as variable temperature and irradiation conditions. In the study, 1Soltech 1STH-215-P model photovoltaic panel is used. The maximum power point tracking is applied with a DC-DC boost converter, and the energy is stored in the battery. Maximum power point tracking algorithms are applied with m-file code using Matlab Function block in Simulink. The m-file codes, the extracted power waveforms and the amount of produced energy are presented in the study. It is observed that the energy performance of the short circuit current and open circuit voltage techniques varies depending on the measurement period, especially in variable weather conditions, while the perturb & observe and the incremental conductance algorithms are the ones that produce the most energy. While the open circuit voltage technique produces more energy than the short circuit current at constant temperature and variable irradiation, the short circuit current algorithm at constant irradiation and variable temperature produces more energy. While two sensors are used for current and voltage measurement in perturb & observe and incremental conductance techniques, the use of a single sensor in short circuit current and open circuit voltage techniques and the simplicity of the algorithms are seen as the advantageous aspects of these techniques.

Synthesis, characterization, and physicochemical studies of the synthesized dimethoxy-Nʹ-(phenylsulfonyl)-benzenesulfonohydrazide derivatives and used as a probe for calcium ion capturing: Natural sample analysis

Two new molecules (2,5-dimethoxy-N′-(phenylsulfonyl)-benzenesulfonohydrazide, DMPSBSH and 2,5-dimethoxy-N′-(phenylsulfonyl)-4-methylbenzenesulfonohydrazide, DMPSMBSH) were synthesized by using a simple condensation method from 2,5-dimethoxy-benzene-1-sulfonyl chloride (DMBSC) and benzenesulphonylhydrazine (BSH) and 4-methyl-benzenesulfonylhydrazine (4-MBSH) respectively in a good yield which were crystallized in MeOH and then re-crystallized from acetone and EtOAc (50:50). Synthesized molecules were characterized by means of spectroscopic techniques for example 1H NMR, 13C NMR, FTIR, and UV–Vis. A probe was furnished by deposition of little layer of DMPSBSH and DMPSMBSH onto a flat GCE with conducting polymer matrix, Nafion (Nf). This furnished probe was used for the impending detection of calcium ion (Ca2+) by using a dependable current-voltage technique. Analytical parameters (Sensitivity, LOD, and LOQ) of the proposed probe (DMPSMBSH/GCE/Nf) towards Ca2+ were calculated from the calibration curve as 2531.65 pAμM−1cm−2, ≈98.25 pM, and 327.5 mM respectively. This imminent DMPSMBSH/GCE/Nf probe applied to the selective determination of Ca2+ in spiked natural samples and found good results.

A Hybrid Photodiode for Solar Tracking Systems

In this work, ruthenium doped ZnO based Al/ZnO:Ru/p-Si/Al diodes were fabricated to explain photoresponse behavior of metal oxide based Schototky diodes. The particle size of the doped zinc oxide film about 168–362 nm with surface roughness 27.735 nm were measured respectively. The electrical properties of the Al/ZnO:Ru/p-Si/Al diode were measured using current voltage (I-V) and capacitance voltage (C-V) techniques. The electronic parameters of the diode were found to change with solar illuminations. The photo switching-off-on behaviour of the diode was analyzed by photoresponse characteristics. The photoresponse parameters of Al/ZnO:Ru/p-Si/Al are changed with Ru content. Finally, some perspectives for future investigation metal oxide based Schottky diodes are discussed as well. The ZnO based Schottky diodes can be used as photosensor in solar tracking and optic communication applications.

Synthesis, characterization, and crystal structure of (E)-Nʹ-(4-Bromobenzylidene)-benzenesulfonohydrazide and its application as a sensor of chromium ion detection from environmental samples

A novel (E)-Nʹ-(4-Bromobenzyledene)-benzenesulfonohydrazide compound was prepared by using an easy condensation procedure from 4-Bromobenzaldehyde and benzenesulphonylhydrazine in a good yield which was crystallized in EtOH. 4-BBBSH was characterized by various spectroscopic techniques for example 1H NMR, 13C NMR, FTIR, and UV–Vis. Structure of the 4-BBBSH molecule was established by using a single crystal X-ray diffraction method (SCXRDM). A selective sensor was modified by deposition of a thin-layer of 4-BBBSH onto a flat GCE with conducting polymer matrix such as Nafion as chemical binder. 4-BBBSH/GCE/Nf sensor was used for the selective detection of metal ion (MI), chromium (Cr3+) by using dependable current-voltage (I–V) technique. Analytical parameters such as sensitivity, LOD, and LOQ of the proposed sensor towards Cr3+ were calculated from the calibration graph as 1898.73 pAμM−1cm−2, ≈95.5 pM, and 318.33 mM respectively. This fabricated 4-BBBSH/GCE/Nf sensor applied to the selective determination of Cr3+ in environmental samples and found satisfactory results.

Microstructural and interface properties of Au/SrTiO3 (STO)/n-GaN heterojunction with an e-beam evaporated high-k STO interlayer

This paper reviews the microstructural and electrical properties of Au/n-GaN metal/semiconductor (MS) diode with an e-beam evaporated SrTiO3(STO) as an insulating layer between the Au and n-GaN substrate. The microstructural properties of STO thin films are assessed by employing XRD and TEM approaches and the results reveal that the STO thin films are formed on n-GaN surface. Then, the Au/STO/n-GaN heterojunction (HJ) type Schottky diode is fabricated and measured its electrical characteristics by current-voltage (I–V) and capacitance-voltage (C–V) techniques. The HJ exhibits lower reverse leakage current compared to the MS diode. Higher barrier height is achieved for the HJ (0.86 eV) than the MS diode (0.67 eV) with ideality factors of 1.86 and 1.21. This implies that the barrier height is modified by the STO insulating layer. Using Z(V,T)i - Vd and ΨS-V plots, the barrier heights of MS diode and HJ are also evaluated and compared with one another. The derived interface state density (NSS) of HJ is lower than the MS diode, demonstrating that the STO layer plays a substantial role in the reduced NSS. Results suggest that the STO thin film is a promising high-k material for the development of new electronic device applications.

Temperature-Dependent Electrical Characteristics of Ni/Au Vertical Schottky Barrier Diodes on β-Ga2O3 Epilayers

Temperature dependent current transport mechanism in Ni/β-Ga2O3 Schottky Barrier Diodes was studied using current-voltage (I-V) and capacitance-voltage (C-V) characterization techniques in the range of 78–350 K. Schottky barrier height ϕb0 and ideality factor ɳ from I-V characteristics were found to be 1.27 eV and 1.12, respectively, at room temperature. Plots of barrier height and ideality factor with inverse of temperature show strong temperature dependency and a deviation from barrier height obtained from C-V characteristics. The temperature dependence of barrier height and ideality factor assigned to barrier inhomogeneity at Ni/β-Ga2O3 interface, and modulated by the potential fluctuation model. Diode turn-on voltage and turn-on resistance at 300 K were found to be 1.08 eV and 7.80 mΩ-cm2, respectively. A large rectification ratio of the order of 1012 was obtained at room temperature and also the rectification ratio of the order of 109 was consistent over the whole temperature range (78–350 K).

The Electrical Motorcycle Charger for Application in a Residence

The aim of this paper is to design the charger for an electric motorcycle and analyze the behavior of voltage and current value during charging. The AC voltage supply from a residence is converted to DC voltage to charge the energy storage system by controlling the voltage and current values suitable for the charge process in all periods. The designed charger is based on the principle of a buck converter with using constant current and constant voltage technique in order to charge a 12 V, 21 Ah lead-acid battery inside the electric motorcycle. By considering the results, the first state of battery charging is a constant current mode by using the current of 5 A with the initial voltage of 55 V. In the second mode, the battery charging is done by constant voltage of 72 V and the current is reduced until the battery is full. Moreover, the charging time is about 6-8 hours.