Dependence Of Electrical Properties Research Articles

Exploration of Chemical Composition of In–Ga–Zn–O System via PEALD Technique for Optimal Physical and Electrical Properties

AbstractIn–Ga–Zn–O (IGZO) material has been researched due to its favorable electrical characteristics for application in thin‐film transistor (TFT) applications such as low off current and relatively high mobility. However, most recently, as the developing and expanding application fields, conventional IGZO is a challenging aspect because higher mobility and excellent step‐coverage are required to be applied to high‐resolution displays and 3D NAND. In this regard, atomic layer deposition (ALD) is suggested as a novel deposition method for tackling issues. Here, this work systematically synthesizes IGZO films with various compositions by the supercycle technique of plasma‐enhanced ALD (PEALD) to determine the optimum metal cation composition range of the IGZO system for high‐mobility TFTs. The trends in the metal composition dependent electrical properties of ALD processed IGZO films are comparable to the previously reported results, while the structural properties are exclusive. Since both microstructure and carrier concentration affect to device characteristics complexly, the optimal In–Ga–Zn region is newly demonstrated via PEALD (XIn: 0.56–0.63, XGa: 0.13–0.17, XZn: 0.17–0.34). In this region, the device exhibits a remarkably high µFE of 41.4–43.7 cm2 V−1 s−1, a low subthreshold swing (SS) of 0.24–0.25 V decade−1, an initial threshold voltage (Vth) of −0.9 to −1.0 V, and a slight Vth shift (0.01 V) under the positive bias temperature stability (PBTS).

Composition dependent structural, electrical, and optical properties of p-type InSb thin film for homojunction device application

A key component of IR detectors and sources is the indium antimonide, having a narrow direct band gap of 0.17eV. The present paper deals with the fabrication, structural, electrical, and optical properties of p-type indium antimonide thin films of about 300 nm thickness by thermal evaporation technique on ultrasonically cleaned glass substrates with different compositions having formula InxSb1-x. Hall measurement indicates that the asfabricated films were p-type, having a carrier concentration of 0.435 x1018to 1.590 x1018 cm-3 and mobility of 3.29 – 6.62 cm2 /V-s for the film thickness of 300 nm. The activation energy (Ea) was determined and found to be in the range of 0.710 – 0.518 eV from the measurement of electrical resistivity of thin films in the temperature ranges of 313 K - 363 K. X-ray diffraction studies revealed the diffraction peaks (111), (220), and (311) confirm the bulk and thin film formation of InSb polycrystalline materials. The grain size (D), dislocation density(δ), and Strain (ε) have been calculated using XRD data. The lattice parameter (a=b=c) was found to be 6.7074Å from the X-ray diffraction method (XRD). The surface morphology study of thin film through scanning electron microscope reveals the formation of nano-grains with grain size ranging between 7.63 nm to 26.32 nm and surface area of 672-1343 nm2 .

STUDY OF STRUCTURAL AND TRANSPORT PROPERTIES OF CuFe2O4 SYNTHESISED VIA LOW COST SOLID STATE REACTION ROUTE

ABSTRACT The ceramic compound CuFe2O4 was synthesised via conventional high-temperature solid-state reaction route. The structural study of the compound was done using X-ray diffraction technique. The preliminary structural study was performed using POWD software and a tetragonal structure was suggested. The Rietveld refinement of XRD (X-ray Diffraction) data was carried out using FullProf software and the refined lattice parameters were obtained as a = 5.80030 Å and c = 8.69400 Å with high tetragonality ratio. The crystallite size and lattice strain were calculated using Williamson–Hall (W-H) plot. The temperature and frequency dependent electrical properties of this compound are analysed using complex impedance technique. The impedance and modulus study of the compound showed the contribution of intra-grain effect to the overall electrical response. The studied ceramic possessed a non-Debye-type relaxation mechanism. The bulk resistance decreased with the increase in temperature, thus showing negative temperature coefficient of resistance behaviour. Modulus and conductivity study showed the evidence of conduction via hopping mechanism inside the material. Frequency-dependent AC conductivity followed Jonscher’s universal power law. The Arrhenius equation was fitted with the temperature-dependent AC conductivity at different frequencies, and activation energies were determined to understand the charge species involved in the conduction mechanism.

Temperature and frequency dependent dielectric and electrical properties of relaxor (Ca1/2W1/2)(Pb1/2Ni1/2)O3 electronic material

In the present study, a solid-state reaction technique is used to formulate and synthesize the (Ca0.5W0.5)(Pb0.5Ni0.5)O3, [CWPN] relaxor perovskite composite. Its structural, morphological, and electrical characteristics have all been revealed so that they may be studied for potential use in electronics and sensors. X-ray diffraction analyses have confirmed the structure to be combination of primary tetragonal along with secondary rhombohedral and orthorhombic phase. Throughout a wide temperature and frequency range (25° – 500° C and 1 kHz–1 MHz), the impedance spectroscopy, dielectric, and a.c. conductivity have all been analyzed. The sample's dielectric spectroscopy confirmed its relaxor properties. On a Nyquist plot, the sample's grain contribution is represented by a single semicircular arc. A replica of a similar circuit was constructed so that its electrical characteristics could be studied. Both the activation energy and the mobility of the charge carriers have been evaluated. Conducting systematic studies of dielectric properties at elevated temperatures is crucial for fundamental characterization and device development, as it allows for the analysis of electrical parameters associated with surfaces, grain borders, or grains.

Optical and temperature dependent electrical properties of poly (vinyl chloride)/copper alumina nanocomposites for optoelectronic devices

Abstract The practical applications of poly (vinyl chloride) have been constrained due to its poor thermal stability, low dielectric constant and inability to shield against ultraviolet (UV) radiation. In this study, we tried to improve the optical properties, thermal stability, temperature-dependent electrical conductivity and dielectric constant using copper alumina (Cu–Al2O3) nanoparticles reinforced poly (vinyl chloride) (PVC). Optical absorption measured with an ultraviolet-visible (UV-visible) spectrometer emphasises the blueshift in absorption edges and decreasing bandgap energies of PVC/Cu–Al2O3 nanocomposites compared to PVC. The presence of Cu–Al2O3 in PVC and its interaction with the polymer were confirmed by FTIR spectroscopy. Thermogravimetric analysis (TGA) demonstrates that nanocomposites have higher thermal stability than PVC, and that thermal stability increases with filler loading. Scanning electron microscopy (SEM) indicates the homogeneous dispersion of nanosized Cu–Al2O3 in the polymer matrix. The activation energy determined by the Arrhenius equation revealed that AC conductivity increases with the addition of nanoparticles up to a specific loading. The dielectric constant increases as a function of temperature and decreases with frequency. The magnitude of AC conductivity and dielectric constant were highest for 7 wt% loaded nanocomposites. The dielectric constant predicted by the Bruggeman and Maxwell-Garnet models were in good agreement with the experimental permittivity. The semiconducting nature of nanocomposites was investigated by impedance analysis. The semi-circular nature of Cole-Cole plots manifests the combination of parallel capacitance with low bulk resistance. The enhanced optical, thermal, electrical and dielectric properties of PVC/Cu–Al2O3 nanocomposites can be utilized in fabricating optoelectronic devices with excellent charge-storing ability.

Temperature-frequency dependent electrical properties of tin oxide-titania based capacitive electronic component

Temperature-frequency dependent electrical properties of tin oxide-titania based capacitive electronic component

Crystallinity Effect on Electrical Properties of PEALD-HfO2 Thin Films Prepared by Different Substrate Temperatures.

Hafnium oxide (HfO2) thin film has remarkable physical and chemical properties, which makes it useful for a variety of applications. In this work, HfO2 films were prepared on silicon through plasma enhanced atomic layer deposition (PEALD) at various substrate temperatures. The growth per cycle, structural, morphology and crystalline properties of HfO2 films were measured by spectroscopic ellipsometer, grazing-incidence X-ray diffraction (GIXRD), X-ray reflectivity (XRR), field-emission scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy. The substrate temperature dependent electrical properties of PEALD-HfO2 films were obtained by capacitance-voltage and current-voltage measurements. GIXRD patterns and XRR investigations show that increasing the substrate temperature improved the crystallinity and density of HfO2 films. The crystallinity of HfO2 films has a major effect on electrical properties of the films. HfO2 thin film deposited at 300 °C possesses the highest dielectric constant and breakdown electric field.

Study of dielectric and electrical properties in Co-(Fe–Ce-Nd) nanosized spinel ferrites

Ce–Nd doped Cobalt ferrite nanoparticles having composition CoFe2-2xCexNdxO4 (where 0.00 ≤x ≤ 0.10) were prepared by co-precipitation method. X-ray diffraction study confirms the formation of single-phase spinel ferrite. Temperature dependent dielectric and electrical properties has been studied with in the frequency range of 20Hz to 3 MHz. Dielectric constant and dielectric loss decrease as frequency increased while ac conductivity exhibit increasing trend with increasing frequency. The alternating current (AC) conductivity data were successfully modeled by using universal Jonscher's power law which implies that hopping of charge carriers is the governing mechanism in the conduction. Impedance study using Nyquist plots shows that grain boundary resistance is higher than the grain interior resistance. Diameter of Nyquist plots decreases with increasing temperature indicating the decrease in impedance and increase in conductivity. DC resistivity show decreasing trend with increasing temperature revealing semiconductor nature of synthesized nanoparticles. Current–Voltage measurements exhibit nonlinear hysteresis loop which authenticate the occurrence of resistance switching effect in synthesized composition.

Electrical and optical properties of hydrogen plasma treated β-Ga2O3 thin films

The behavior of H in β-Ga2O3 is of substantial interest because it is a common residual impurity that is present in β-Ga2O3, regardless of the synthesis methods. Herein, we report the influences of H-plasma exposure on the electric and optical properties of the heteroepitaxial β-Ga2O3 thin films grown on sapphire substrates by chemical vapor deposition. The results indicate that the H incorporation leads to a significantly increased electrical conductivity, a greatly reduced defect-related photoluminescence emission, and a slightly enhanced transmittance, while it has little effect on the crystalline quality of the β-Ga2O3 films. The significant changes in the electrical and optical properties of β-Ga2O3 may originate from the formation of shallow donor states and the passivation of the defects by the incorporated H. Temperature dependent electrical properties of the H-incorporated β-Ga2O3 films are also investigated, and the dominant scattering mechanisms at various temperatures are discussed.

Optical, thermal and temperature dependent electrical properties of chlorinated natural rubber/copper alumina nanocomposites for flexible electrochemical devices

Optical, thermal and temperature dependent electrical properties of chlorinated natural rubber/copper alumina nanocomposites for flexible electrochemical devices

Emphasized temperature dependent electrical properties study of fabricated ZnO/PVA/PANI nanocomposite films

Polyvinyl alcohol-Polyaniline composite films with different amounts of zinc oxide (ZnO) (0.2%, 0.4%, 0.6% and 1%)were prepared by in situ polymerization followed by film casting and drying. The samples, ZnO and PPZ films, were characterized by various techniques. The presence of ZnO in PPZ films was confirmed by the X-Ray Diffractometer (XRD). The surface morphology of the ZnO and PPZ films were examined by the Field-Emission Scanning Electron Microscopy(FESEM). The formation of absorption bonds corresponding to the PPZ films were illustrated by the Fourier Transform Infrared Spectroscope (FTIR)analysis. The films were found to be stable up to 150 °C, which was confirmed from the Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analyzer (TGA) technique. The absorption peaks of PPZ, around visible and UV region, was studied by the UV–Vis spectra. The electrical conductivity plots obtained from the impedance analyzer, between frequency ranges of 10 Hz to 100 kHz, show that the increase in concentration and temperature of the samples resulted in the higher conductivity of the PPZ films. For 1% ZnO concentration at 150 °C, the AC conductivity of PPZ1 was found to be 20.06 S/m. Such conductivity behavior samples render the applicability of the PPZ films.

Copper-Content Dependent Structural and Electrical Properties of CZTS Films Formed by “Green” Colloidal Nanocrystals

Thin films of colloidal CZTS nanocrystals (NCs) synthesized using a “green” approach in water with a variation of the copper-to-tin ratio are investigated by Raman scattering, mid-infrared (molecular vibrations) and near-infrared (free carrier) absorption, X-ray photoemission spectroscopy (XPS), electrical conductivity, and conductive atomic force microscopy (cAFM). We determined the effect of the actual Cu content on the phonon spectra, electrical conductivity, and spectral parameters of the plasmon band. An increase in the electrical conductivity of the NC films upon annealing at 220 °C is explained by three factors: formation of a CuxS nanophase at the CZTS NC surface, partial removal of ligands, and improved structural perfection. The presence of the CuxS phase is concluded to be the determinant factor for the CZTS NC film conductivity. CuxS can be reliably detected based on the analysis of the modified Auger parameter of copper, derived from XPS data and corroborated by Raman spectroscopy data. Partial removal of the ligand is concluded from the agreement of the core-level XPS and vibrational IR spectra. The degree of lattice perfection can be conveniently assessed from the Raman data as well. Further important information derived from a combination of photoelectron and optical data is the work function, ionization potential, and electron affinity of the NC films.

Precursor molarity dependent growth rate, microstructural, optical and electrical properties of spray pyrolytically deposited transparent conducting ZnO thin films

The spray pyrolysis method is employed to deposit ZnO films at different precursor molarity (SC). The X-ray diffraction study reveals the polycrystalline film growth along [0 0 2], c-axis direction. The SC dependent variations of microstructural parameters are considered to propose the film’s growth mechanism. The growth rate increases with SC due to the rising number of Zn species till SC ​= ​0.5 ​M, above which it slightly decreases due to oxygen insufficiency. The rise in SC causes film thickness and crystallite size to increase, whereas bandgap energy decreases from 3.35eV to 3.22eV. At optimized SC ​= ​0.3 ​M, the film shows 96.3% transmittance with maximum electrical conductivity (93.9 ​Ω-1-cm−1), carrier concentration (4.94 ​× ​1019/cm3) and mobility (11.9 ​cm−2V−1s−1). The maximum figure of merit (1.76 ​× ​10−3 ​Ω−1) with the least sheet resistance (388 ​Ω/□) is recorded for films deposited at SC ​= ​0.3 ​M.

Resistive switching effect in RE-Doped cobalt ferrite nanoparticles

Spinel ferrite along with numerous important properties, also exhibit resistive switching effect. Cerium (Ce) doped Co-ferrite nanoparticles having composition CoFe2-xCexO4 (where x = 0.0, 0.05, 0.15, 0.20) were synthesized by co-precipitation synthesis route. X-ray Diffraction analysis confirmed the formation of cubic spinel phase with minor amount of impurities. Frequency dependent dielectric and electrical properties were studied at room temperature within frequency range of 20 Hz to 3 MHz. Dielectric constant, dielectric losses and AC conductivity decreases with cerium substitutions which is usual trend observed in ferrite materials. Modified Debye function was employed to fit Dielectric constant (ε′)- frequency (f) data. Jonscher's power law was employed to study AC conductivity. DC resistivity decreased with increasing temperature. DC resistivity and drift mobility decreased with cerium substitution while activation energy increased. Current–Voltage (I–V) curves of the synthesized composition were studied at room temperature. Current–Voltage (I–V) curves showed nonlinear hysteresis loop like behavior. Current follow different values for forward and reversed applied DC voltage which confirmed that resistive switching effect exit in studied samples. Sample with Ce composition x = 0.25 exhibit larger hysteresis loop than that of other compositions. This shows that sample for Ce composition x = 0.25, can be employed for nonvolatile Resistive Random-Access Memory (ReRAM) applications. Resistive switching effect was explained by utilizing Space-charge-limited current (SCLC) conduction model and by formation of a Schottky barrier at the metal-semiconductor interface.

Water-assisted crystallization of amorphous indium zinc oxide films

Transparent conductive materials based on indium oxide remain yet irreplaceable in various optoelectronic applications. Amorphous oxides appear especially attractive for technology as they are isotropic, demonstrate relatively high electron mobility and can be processed at low temperatures. Among them is indium zinc oxide (IZO) with a large zinc content that is crucial for keeping the amorphous state but redundant for the doping. In this work we investigated water-free and water containing IZO films obtained by radio frequency sputtering. The correlation between temperature driven changes of the chemical state, the optical and electrical properties as well as the progression of crystallization was in focus. Such characterization methods as: scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, temperature dependent Hall-effect measurements and others were applied. Temperature dependent electrical properties of amorphous IZO and IZO:H2O films were found to evolve similarly. Based on our experience in In2O3:H2O (In2O3:H or IOH) we proposed an explanation for the changes observed. Water admixture was found to decrease crystallization temperature of IZO significantly from ∼ 550 °C to ∼ 280 °C. Herewith, the presence and concentration of water and/or hydroxyls was found to determine Zn distribution in the film. In particular, Zn enrichment was detected at the film’s surface respective to the high water and/or hydroxyl amount. Raman spectra revealed a two-dimensional crystallization of w-ZnO which precedes regardless water presence an extensive In2O3 crystallization. An abrupt loss of electron mobility as a result of crystallization was attributed to the formation of ZnO interlayer on grain boundaries.

Bioinspired elastomer composites with programmed mechanical and electrical anisotropies

Concepts that draw inspiration from soft biological tissues have enabled significant advances in creating artificial materials for a range of applications, such as dry adhesives, tissue engineering, biointegrated electronics, artificial muscles, and soft robots. Many biological tissues, represented by muscles, exhibit directionally dependent mechanical and electrical properties. However, equipping synthetic materials with tissue-like mechanical and electrical anisotropies remains challenging. Here, we present the bioinspired concepts, design principles, numerical modeling, and experimental demonstrations of soft elastomer composites with programmed mechanical and electrical anisotropies, as well as their integrations with active functionalities. Mechanically assembled, 3D structures of polyimide serve as skeletons to offer anisotropic, nonlinear mechanical properties, and crumpled conductive surfaces provide anisotropic electrical properties, which can be used to construct bioelectronic devices. Finite element analyses quantitatively capture the key aspects that govern mechanical anisotropies of elastomer composites, providing a powerful design tool. Incorporation of 3D skeletons of thermally responsive polycaprolactone into elastomer composites allows development of an active artificial material that can mimic adaptive mechanical behaviors of skeleton muscles at relaxation and contraction states. Furthermore, the fabrication process of anisotropic elastomer composites is compatible with dielectric elastomer actuators, indicating potential applications in humanoid artificial muscles and soft robots.

An investigation of the temperature- and frequency- dependent conductivity behavior and electrical properties of Ba0.97La0.02Ti0.9Nb0.08O3 compound using impedance spectroscopy

Ba0.97La0.02Ti0.9Nb0.08O3 (distinguished as BLT0.9Nb0.08) ceramic were prepared via the molten-salt reaction. The pellets were sintering at 800 °C for 24 h. The X-ray diffraction (XRD) exhibits the crystallization of our ceramic sample in the tetragonal structure with P4/mmm space group. The scanning electronic microscope (SEM) analyses shows the growth of grain size was founded 260 nm. SEM defines the formation of the high-density ceramic sample. Impedance, modulus and electrical transport properties of the ceramic have been obtained via the impedance spectroscopy at different frequencies (102–106 Hz) and temperatures (500–600 K). The Nyquist plots exhibits the existence of the effect of inter- and intra- grains in our sample. The electrical transport properties of our polycrystalline can be clarified with the help of charge transfer by hopping process. The complex electrical modulus plot is used to establish the dielectric relaxation. The frequency dependence of conductivity plot follows the universal Jonscher power law. What's more, the dielectric constant decreased with rising frequency. This is allocating to Maxwell-Wagner (M-W) interfacial polarization. All the above considered factors recommend that the ceramic material may be favor as an electronic component of several devices.

Piezoresistive Prediction of CNTs-Embedded Cement Composites via Machine Learning Approaches

Conductive cementitious composites are innovated materials that have improved electrical conductivity compared to general types of cement, and are expected to be used in a variety of future infrastructures with unique functionalities such as self-heating, electromagnetic shielding, and piezoelectricity. In the present study, machine learning methods that have been recently applied in various fields were proposed for the prediction of piezoelectric characteristics of carbon nanotubes (CNTs)-incorporated cement composites. Data on the resistivity change of CNTs/cement composites according to various water/binder ratios, loading types, and CNT content were considered as training values. These data were applied to numerous machine learning techniques including linear regression, decision tree, support vector machine, deep belief network, Gaussian process regression, genetic algorithm, bagging ensemble, random forest ensemble, boosting ensemble, long short-term memory, and gated recurrent units to estimate the time-independent and -dependent electrical properties of conductive cementitious composites. By comparing and analyzing the computed results of the proposed methods, an optimal algorithm suitable for application to CNTs-embedded cementitious composites was derived.

Investigation of the Structural and Temperature Dependent Electrical Properties of Mzno (M = CE and Sm) Schottky Diode Devices Fabricated Using the Sol-Gel Spin Coating Technique

Investigation of the Structural and Temperature Dependent Electrical Properties of Mzno (M = CE and Sm) Schottky Diode Devices Fabricated Using the Sol-Gel Spin Coating Technique

Enhancement on the electrical and optical behaviour of ZnFe2O4 nano particles via transition metal substitution

The present study aimed to investigate the behavior of nano Zinc Ferrite particles by copper substitution in various concentrations in order to fabricate novel material for future use in optoelectronic and electromagnetic shielding devices. To that end, Nano crystalline Zn-Cu ferrites (Cu(1-X)ZnXFe2O4: x = 0, x = 0.25, x = 0.5, x = 0.75 and x = 1) were prepared using combustion technique with egg white as a fuel. The prepared powder samples were investigated by various characterization methods such as X-ray diffraction analysis (XRD), High resolution scanning electron microscope analysis (HRSEM), UV–Vis- DRS spectra and electrical analysis. The physical investigations of the final product revealed that the lattice structure of Cusubstituted at Znsites developed the spinel ferrite particles with single crystalline phase at room temperature (RT), with morphological, optical and temperature dependent electric properties. Substitution of transition metals has a significant impact on the microstructure, crystal structure, electrical parameters and optical properties of zinc ferrite nanoparticles, according to the findings. Furthermore, the dielectric constant (εr) and dielectric loss (tanδ) are investigated and found to be strongly dependent on frequency and temperature. Enhancements of electrical resistivity of mixed ferrites suggest the use of these ferrites in EM shielding devices.