Electrical Properties Of Thin Films Research Articles

Investigation of the structural, morphological, optical, and electrical properties of thin films: application of effective medium theories to CdO/Co3O4 composites

Investigation of the structural, morphological, optical, and electrical properties of thin films: application of effective medium theories to CdO/Co3O4 composites

Enhanced Thermal Stability of Conductive Mercury Telluride Colloidal Quantum Dot Thin Films Using Atomic Layer Deposition.

Colloidal quantum dots (CQDs) are valuable for their potential applications in optoelectronic devices. However, they are susceptible to thermal degradation during processing and while in use. Mitigating thermally induced sintering, which leads to absorption spectrum broadening and undesirable changes to thin film electrical properties, is necessary for the reliable design and manufacture of CQD-based optoelectronics. Here, low-temperature metal-oxide atomic layer deposition (ALD) was investigated as a method for mitigating sintering while preserving the optoelectronic properties of mercury telluride (HgTe) CQD films. ALD-coated films are subjected to temperatures up to 160 °C for up to 5 h and alumina (Al2O3) is found to be most effective at preserving the optical properties, demonstrating the feasibility of metal-oxide in-filling to protect against sintering. HgTe CQD film electrical properties were investigated before and after alumina ALD in-filling, which was found to increase the p-type doping and hole mobility of the films. The magnitude of these effects depended on the conditions used to prepare the HgTe CQDs. With further investigation into the interaction effects of CQD and ALD process factors, these results may be used to guide the design of CQD-ALD materials for their practical integration into useful optoelectronic devices.

Preparation of Sn-Doped Ga2O3 Thin Films and MSM Ultraviolet Detectors Using Magnetron Co-Sputtering.

Sn-doped Ga2O3 thin films and metal-semiconductor-metal (MSM) ultraviolet detectors were prepared using the co-sputtering method to enhance their photoelectric performance. The results revealed that Sn doping can effectively change the optical and electrical properties of thin films, greatly improving the photoelectric responsiveness of the devices. Through microstructure testing results, all of the thin film structures were determined to be monoclinic beta phase gallium oxide. At a DC power of 30 W, the thickness of the Sn-doped thin film was 430 nm, the surface roughness of the thin film was 4.94 nm, and the carrier concentration, resistivity, and mobility reached 9.72 × 1018 cm-3, 1.60 × 10-4 Ω·cm, and 45.05 cm3/Vs, respectively. The optical results show that Sn doping clearly decreases the transmission of thin films and that the bandgap can decrease to 3.91 eV. Under 30 W DC power, the photo dark current ratio of the detector can reach 101, time responses of tr = 31 s and tf = 22.83 s were obtained, and the spectral responsivity reached 19.25 A/W.

Effect of particle size on optical and electrical properties of thin films – a simulation approach

This paper presents a simulated investigation of the relationship between surface roughness and particle size as well as the resulting impact of the both on the thin film’s physical and optical properties. Non-porous thin films are created through computer simulation for a range of particle sizes following the random deposition with a surface relaxation approach. For the deposited thin films different fundamental parameters like transmittance, reflectance, absorption coefficients, frequency dependent dielectric constants, loss angle, refractive indices, optical band gap have all been calculated and in this process of calculation the fundamental values of two different materials; zinc oxide (ZnO and cadmium selenide (CdSe) are taken. It has been seen that when the particle sizes are comparable the calculated values of optical band gap of both ZnO and CdSe matches well with the experimental values of the same reported by others. This is probably the first effort to develop a direct relation between the particle size with different fundamental optical properties of different materials through simple simulation which agrees well with the experimental result. This would definitely help the experimental researchers in the field of material science to design their experiments as per the desired requirements.

Exploring the Post-Annealing Influence on Stannous Oxide Thin Films via Chemical Bath Deposition Technique: Unveiling Structural, Optical, and Electrical Dynamics

Stannous oxide (SnO2) thin films have garnered significant attention for their promising applications in various electronic and optoelectronic devices. In this study, we investigate the impact of post-annealing on the structural, optical, and electrical properties of stannous oxide thin films deposited using the chemical bath deposition (CBD) technique. The thin films were prepared on a Borosilicate glass substrate, followed by a controlled annealing process to enhance their performance. Structural analysis was conducted using techniques such as X-ray diffraction (XRD) to examine the cubic crystalline structure and the crystallite size increase induced by post-annealing. The results revealed alterations in grain size from the SEM and the purity of samples confirmed from EDX results. The optical properties of the Stannous oxide thin films were examined using UV-Vis spectroscopy. The optical absorption and bandgap characteristics were analyzed to understand how post-annealing influences the optical behavior of the thin films. Where the optical absorption was 320nm and the bandgap ranges were 3.86eV to 3.83eV. Furthermore, the electrical properties of the thin films were evaluated semiconducting nature, and conductivity increased with rising post-annealing. The findings from this study contribute to the understanding of the role of post-annealing in tailoring the properties of Stannous oxide thin films. The optimization of structural, optical, and electrical characteristics is crucial for their successful integration into electronic and optoelectronic devices.

Variation of electrical properties with temperature for polyethylene oxide doped with 0.1 wt. % iodine

The electrical properties of thin films made of polyethylene oxide (PEO) dispersed with dopants fixed amount of iodine (0.1 wt. %) were studied using the AC impedance technique. The films were prepared by electrically casting method. In this present work, the variation of AC electrical conductivity with temperatures ranging from 30 oC to 55 oC at a frequency of 200 kHz for (PEO) film doped with 0.1wt. % iodine and undoped (PEO) film were studied. Physical quantities and parameters such as AC conductivity, impedance, dielectric constant, and dielectric loss, were determined. The observed values of the impedance (Z), dielectric constant ('), dielectric loss ("), and AC-conductivity (σAC) showed temperature dependence. It was found that the dielectric constant and the dielectric loss of the prepared thin films increased with doped (0.1wt. %) iodine complexes and also increased with the increase of temperature according to the polarization processes.

Design of Electrical Sheet Resistance of Thin Film Measurement System Based on GM Cryocooler in Cryogenic Temperature

The determination of the dependencies of the electrical resistivity of the thin film to temperature is of great importance both for understanding the conduction mechanism and for numerous technical applications of these films. In this work, to characterize, the electrical properties of thin films, a GM cryocooler-based automatic board temperature range electrical properties measurement system has been constructed. The system can measure multiple samples simultaneously. The cooling process was simulated using the time-discrete differencing to validate the optimized device design parameters and minimize heat losses. Furthermore, the temperature-dependent sheet resistance results were compared with the results from the physical property measurement system.

On the physical meaning of the geometric factor and the effective thickness in the Montgomery method

The Montgomery method is extensively employed to determine the electrical resistance tensor of anisotropic samples. This technique relies on two essential parameters describing an isotropic system: the geometric factor (H1) and the effective thickness (E). The numerical values of these parameters are intricately linked to the dimensions of an isotropic block equivalent to the studied anisotropic specimen. While these parameters hold importance, the physical interpretation of these terms still lacks clarity. In this study, we utilized the finite element method to simulate electrical transport experiments across samples of various shapes. Utilizing the Electric Currents physics interface in the COMSOL program, we were able to provide a comprehensive analysis of the physical meaning of these parameters to accurately determine the electrical properties of thin films and wafers. The presented findings related to the physical interpretation of H1 and E terms make substantial contributions to the field of electrical transport experimental techniques, which are fundamental to design advanced materials for technological applications and understand their physical properties.

Optical and electrical properties of thin films of MnS/metal/MnS for photocatalysis and gas sensing applications

Thin films of manganese sulfide (MnS) with interlayers of silver and copper were prepared using the thermal evaporation technique for applications in photocatalysis and gas sensing. The structure, morphology, optical, and electrical properties of the deposited films were described by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), UV/VIS/NIR spectrophotometer, and two-probe technique. Various parameters such as crystallite size, micro-deformation, dislocation density, optical energy gap, refractive index, extinction coefficient, Urbach energy, dielectric constants, dispersion parameters, activation energy, mobility and, Seebeck coefficient were determined. According to the experimental results, XRD analysis revealed that the MnS powder has a crystalline structure with a cubic phase. While the pure MnS thin films exhibited an amorphous structure, the addition of metals (Ag and Cu) as interlayers resulted in a distinct crystallinity. The pure MnS films had a direct optical energy gap of 3.17 eV, which changed to an indirect transition with energy gaps of 2.43 eV and 2.50 eV when Ag and Cu interlayers were added, respectively. The refractive index values and dispersion of the films depended on the type of interlayer, with all films exhibiting normal dispersion. The temperature dependence of the sheet resistance indicates a semiconducting behavior of the samples, and the addition of the interlayer metal reduced the sheet resistance. Overall, the results suggest that thin films of MnS and MnS/metal/MnS hold promise for organic photocatalysis and gas sensor applications, respectively.

Pengaruh Konsentrasi Perkursor terhadap Sifat Listrik dari Lapisan Tipis

A thin layer is a layer made from organic or non-organic materials which are semiconductors, conductors and insulators. This research aims to determine the effect of precursor concentration on the electrical properties of thin films. Variations in precursor concentration used were 0.025 M, 0.05 M, and 0.075 M. CuSnO3 thin films were characterized by UV-DRS, XRD, FPP, and SEM. The method used in this research is sol-gel. The sol-gel process is used because of its ability to control the surface properties of oxide composites. The results of the band-gap test the variation in precursor concentration obtained by the band-gap value becomes smaller with increasing concentration. The lowest band-gap value in variations in adding an MEA volume of 2 ml, the optimum band-gap value is 2.1706 eV. The results of the FPP test on a thin layer of CuSnO3 precursor concentration of 0.05 M with an optimum MEA of 2 ml obtained a resistivity value of 0.0005671 Ωm with a conductivity value of 173.5809 Ω^(-1) m^(-1).

A systematic study to investigate the effects of x-ray exposure on electrical properties of silicon dioxide thin films using x-ray photoelectron spectroscopy.

X-ray photoelectron spectroscopy (XPS) is generally used for chemical analysis of surfaces and interfaces. This method involves the analysis of changes in binding energies and peak shapes of elements under consideration. It is also possible to use XPS to study the effect of x-ray radiation on the electrical properties of thin films. We measured the Si 2p peak using x-ray powers of 300 and 150W on ∼135nm silicon dioxide (SiO2) thin films grown on both n- and p-type substrates while applying DC or AC external biases. Using the shifts in the binding energy of the Si 2p peak, we calculated the resistances and the capacitances of the SiO2 thin film. The way that the binding energies of the Si 2p peak and the capacitance of the thin film change as a function of the type of Si substrate and the power of the x-ray are explained using band bending.

PVA-Starch-Based Biodegradable Polymer Electrolytes for Electrochemical Devices

Photovoltaic and electrochemical devices have been vital for the past two decades. These devices are capable of solving the coming energy crisis. One of the essential components of these devices is electrolytes. These electrolytes have been replaced in the past few decades by solid polymer electrolytes. The specialty of these solid polymer electrolytes is that they can be grown in a thin film and are also leak-proof. We have used biodegradable polymers like PVA, starch, and some novel salts. These polymer-based thin films were fabricated using standard solution-cast techniques with different wt% of slats in a PVA-Starch-based polymer system. The impedance spectroscopy was performed to analyze the electrical properties of thin films. The highest conductivity of the system was obtained at 20wy% of salt. The conductivity values increase from 1.46 × 10−6 S/cm to 2.69 × 10−6 S/cm. Furthermore, the concentration and mobility of charge carriers were calculated to explain the change in the conductivity pattern. This calculation was done with the Trukhan model. It is observed that the conductivity pattern follows the mobility of charge carriers.

Oxygen Plasma Treatment to Enable Indium Oxide MESFET Devices

AbstractMetal‐semiconductor field‐effect transistor (MESFET) devices based on pulsed laser deposition (PLD) grown In2O3 thin films with on–off ratios exceeding 6 orders of magnitude and low sub‐threshold swing values close to the thermodynamic limit are reported. Oxygen plasma treatment and compensation doping with Mg are utilized to suppress the accumulation of electrons at the surface of In2O3, which is a major obstacle for its use as an active material in electronic devices. The influence of both methods is investigated on the electrical properties of thin films as determined by Hall effect measurements on samples of varying film thickness. Using the performance of vertical Schottky barrier diodes as a benchmark, fundamental plasma parameters such as input power and background gas pressure are optimized.

Structure and Properties of Thin Magnetron Films of Cadmium Arsenide on Various Substrates

Purpose of the study. Synthesis of cadmium arsenide magnetron films on various substrates and study of their structure, composition, optical and electrical properties.Methods. The deposition of thin films of cadmium arsenide was carried out by the method of non-reactive highfrequency magnetron sputtering in an argon atmosphere. The structure and composition of the films were studied using X-ray phase analysis, scanning electron microscopy, energy dispersive analysis, and small-angle X-ray diffractometry. Optical studies were performed using Raman spectroscopy. The results of a study of the electrical properties of thin films of cadmium arsenide are presented.Results. On silicon, sapphire, and strontium titanate substrates, thin films of the Dirac semimetal, cadmium arsenide, were obtained with a thickness of about 40 nm. A study of their structure and composition showed a significant effect of annealing in an argon atmosphere following deposition on the crystallinity of the film. After annealing, regardless of the crystal structure of the substrate, partial orientation of the film with the (112) texture axis. The films closest to the stoichiometric composition were obtained by deposition followed by annealing onto an oriented strontium titanate substrate, and to the crystal structure of cadmium arsenide single crystals of a film on a sapphire substrate. Annealing also leads to a smoothing of the film surface, a decrease in structural defects, and the transition of the fractal dimension of its topology to two-dimensional from close to three-dimensional immediately after deposition. The optical properties after annealing also change, which indicates their transition from a polycrystalline (amorphous) state to a single-crystal (textured).Conclusion. Experimental studies of the structure and properties performed by various methods made it possible to establish that single-crystal or textured cadmium arsenide films suitable for studying the manifestation of topological properties can be obtained by controlled annealing.

Influence of ITO Target on Structural, Optical, and Electrical Properties of Thin Films Deposited by Magnetron Sputtering

Indium tin oxide (ITO) targets possess good performances, thereby used to produce high-quality ITO films in transparent electrodes of various optoelectronic devices. The performance of the target greatly affects the performances of prepared ITO films. However, effect of the overall performance of ITO targets on ITO films performance is still not fully understood. ITO films were prepared with four targets by magnetron sputtering in the similar condition in this study. Effects of crystal structure, resistivity, and oxygen content of the targets on photoelectric performances of ITO films were all evaluated. Results showed the important effect of target properties on obtained film characteristics. ITO films prepared by low resistivity targets are more evenly distributed on the substrate surface. Meanwhile, oxygen content of obtained ITO films decreased as oxygen content of ITO targets used in sputtering process increased. This also significantly improved the photoelectric performances. ITO thin films deposited using targets with low resistivity and low oxygen content exhibited excellent photoelectric performances. In this experiment, the prepared ITO film illustrated the lowest resistivity of 1.75×10−4 Ω·cm and average transmittance of 90.5%. In sum, these findings provided a certain experimental basis for further improving the performances of ITO films.

Synergistic effect of strain and oxygen vacancy on the ferroelectric properties of hafnium oxide-based ferroelectric films

In this paper, a multiphase coexistence phase field model considering mobile oxygen vacancy is established to investigate the synergistic effect of strain and oxygen vacancy on the ferroelectric properties of hafnium oxide-based ferroelectric films. Uniform strain introduced by flat substrate and heterogeneous strain caused by miscut substrate are considered. Our study demonstrates that whether the HfO2 film is under flat substrate-induced strain or miscut substrate-induced strain, the regulation of oxygen vacancy concentration on the ferroelectric phase transition and domain switching of the film is double-sided. When the oxygen vacancy concentration is 1 × 1020 cm−3, the film under 1.2 % uniform strain reaches a maximum remanent polarization of 0.36 C/m2. The optimal concentration interval of oxygen vacancy can be widened by −1.2 % flat substrate-induced uniform strain or 6° and 8° miscut substrate-induced heterogeneous strain. These results embodied the synergistic relationship between oxygen vacancy and strain in regulating the ferroelectric properties of hafnium-oxide based films, which offers guidance for us to understand the phase transition behavior of hafnium-based ferroelectric films and to optimize the electric properties of thin films in device applications.

Characterization of CuO doped CdO nanomaterials synthesized by sol gel spin coating and hydrothermal method

CuO-CdO nanomaterials were synthesized by sol gel spin coating and hydrothermal methods. Undoped CdO and 0.2%, 0.5%, 1%, and 2% CuO doped CdO were produced as thin films and nanopowders. The structural, optical, and electrical properties of the thin films and nanopowders produced were investigated. It was determined by X-ray diffraction (XRD) analysis that thin films and nanopowders were polycrystalline and face-centered cubic structures. From Atomic Force Microscope (AFM) images, it was observed that the structure of the thin films was homogeneous and dense rod-shaped structures, and the nanopowders were urchin-like structures consisting of spherical nanoparticles from the Field Emission Scanning Electron Microscopy (FESEM) images. It was determined that nanopowder and thin films have direct band transition from Ultraviolet–visible spectroscopy (UV–Vis) analysis. From all the results obtained, it was concluded that structural, optical, and electrical properties of thin films and nanopowders vary depending on the doping rate and method differences.

Effect of the thickness on electrical resistance of thin diamond-like carbon coatings on silicon substrate

The relationship between sp2/sp3-hybridizations ratio of atomic bonds in diamond-like carbon ( DLC --- Diamond-Like Carbon) and its electrical resistivity for coatings with a thickness in the range 22-70 nm prepared by vacuum arc deposition on silicon substrate of the KDB-8 brand has been established. It is established, that an increase in the coating thickness from 22 to 70 nm is accompanied by a decrease in the specific transverse electrical resistance of samples from 17 to 2 GΩ·m. This effect is explained by an increase in the proportion of carbon atoms with sp2-hybridization of electronic orbitals from 86 to 91%, which leads to the appearance of an additional number of π-bonds. A mathematical model, describing the spatial distribution of current when measuring transverse I-V characteristic, has been developed. The results obtained will be useful in creating resistive layers on the electrodes of gas-discharge detectors of charged particle to limit the amount of current in the event of rare spark discharges inside them caused by the registration of random highly ionizing particles. Keywords: ( DLC), electrical properties of thin films, hybridization of electronic orbitals, Raman scattering, I-V characteristic.

Li diffusion and surface segregation in K0.5Na0.5NbO3 films grown by Pulsed Laser Deposition

Potassium Sodium Niobate has recently raised particular attention in the field of piezoelectric perovskites thanks to its remarkable piezoelectric properties and high Curie temperature. Previous works have shown that slight Lithium (Li) doping can improve the piezoelectric properties and reduce leakage of stoichiometric K0.5Na0.5NbO3 (KNN). In this paper, evidence is provided that this is not the case for thin films synthesized by Pulsed Laser Deposition, at growth temperature high enough to induce the (001) orientation on a Pt(111) /TiO2/SiO2/Si template. The high mobility of alkali ions leads to Li surface segregation and high non-uniformity of Li doping over the film thickness. This is accompanied by a degradation of KNN thin film electrical properties upon Li doping, with an increase in leakage currents by up to one order of magnitude which impedes a macroscopic piezoelectric characterization. On the other hand, local piezoelectric properties investigated by Piezoresponse Force Microscopy are unchanged upon doping. The results clearly point out the critical issues regarding the growth method to obtain a uniform doping of KNN with light elements such as Li. Due to the high mobility of this species, sizable migration phenomena can be thermally activated in physical vapor deposition processes with high thermal budget, ultimately hampering the envisaged benefits of Li on piezoelectric response.

Enhancement of surface electrical performances of epoxy film by blending with fluorinated and crosslinking monomer

• Fluorinated monomers were synthesized through a facile method to prepare fluorinated epoxy films. • Effects of introducing –CF 3 groups on physicochemical characters of the films are studied. • Electrical strength of the fluorinated film was evidently enhanced. In order to introduce fluorine-containing functional groups into epoxy resins to stably enhance the surface electrical properties of thin films, the trifluoromethyl group containing diglycidyl ethers bisphenol A (F-DGEBA) monomer was prepared by a simple and environmentally friendly method. Further, the film was obtained by blending the prepared monomers with DGEBA in different proportions and curing at high temperature with methyl tetrahydrophthalic anhydride (MTHPA). The prepared films not only have improved hydrophobic properties, but also exhibit better surface electrical properties. With the increase of the content of F-DGEBA, the epoxy resin films have higher surface insulation strength and better potential decay performance, which is due to the existence of –CF 3 groups changing the distribution of deep and shallow traps. Compared with the non-fluorinated film, the flashover voltage of the fluorinated film with the best electrical properties is increased by 32.2%, and the potential decay rate is also much faster.