Electrical Properties Of Films Research Articles

Effect of Cu Doping on Structural, Optical, and Electrical Properties of Sn2S3 Thin Films Prepared by Spray Pyrolysis

Effect of Cu Doping on Structural, Optical, and Electrical Properties of Sn2S3 Thin Films Prepared by Spray Pyrolysis

Structural, optical, electrical and gas sensor properties of Fe-doped CdO thin films synthesized by spray pyrolsis

In this study, the structural, optical, electrical and gas sensor properties of Fe-doped CdO thin films synthesized using the spray pyrolysis method were investigated as a function of Fe doping. The characterizations of the thin films were made by using X-ray diffraction (XRD), X-ray photoelectron (XPS), ultraviolet–visible (UV-VIS), field emission-scanning electron microscope (FE-SEM), atomic force microscope (AFM) and Hall measurements. In addition, the response values of the films for H2 gas were determined by a current-sensitive gas sensor measurement system. XRD analyzes revealed that the produced films were in polycrystalline cubic structure and their unit cell volumes were reduced by Fe doping. The mean particle size and mean dislocation density of Fe doped samples were obtained as 11.99 nm and 6.98 × 1015 (line/m2), respectively. XPS results showed that the experimentally obtained doping ratios of the produced films were very close to the planned doping ratios and the formation of CdxFe(1-x)-O2 and CdxFe(1-x)-O3 on the surfaces of the samples decreased with the increment of Fe doping. UV-VIS measurements demostrated that the band gap is generally reduced due to doping, in line with the Moss-Burstein effect. According to Hall results, the mobility of the samples increases with increasing doping. SEM and AFM analyzes revealed that Fe doping to CdO causes nanoroads formation on thin film surfaces, and nanoroads disappear in 4 % and 5 % doped films. In addition to the specified characterizations, how these changes in the surface morphology of the films with Fe doping affect the H2 gas responses of the samples is also explained in the study.

Study on the preparation of InN films under different substrates and nitrogen-argon flow ratios and the effect of operating temperature on carrier transport in p-NiO/n-InN heterojunctions

In this paper, the properties of indium nitride (InN) semiconductor films deposited by magnetron sputtering were studied. The effects of different substrates (Al2O3, ITO and Si) and different nitrogen-argon flow ratios on the crystal quality of InN films were compared. The crystal structure, surface morphology, optical and electrical properties of InN films were systematically studied. The results showed that the crystallization quality of InN thin film was the best when the flow ratio of nitrogen to argon was 30/0 on Al2O3 substrate. Then the p-NiO/n-InN/AlN heterojunction device was prepared on Al2O3 by using AlN as buffer layer, and the electrical properties of the devices at different operating temperatures were analyzed. Finally, high rectification characteristics and good temperature stability were obtained. This study provides a reference for the preparation of InN films on different substrates and the application of InN-based devices.

Effect of Nickel doping on the Structural, Optical, and electrical properties of titanium dioxide thin films for the application of sensing devices

Thin films of pristine titanium dioxide (TiO2) and doped with different concentrations (0–8) at.% of nickel (Ni) were synthesized onto transparent glass substrates using the spray pyrolysis deposition technique. Field emission scanning electron microscopy revealed the porous and agglomerated surface morphology of the films. X-ray diffractometer demonstrated the anatase crystal structure with a nominal increment of (101) peak. The shifting of peak position revealed the expansion of the unit cell volume from 134.64 to 137.54 (Å)3 whereas crystallite size increased from 34 to 63 nm. Using the Fizeau fringes technique, the thickness of the films was determined between 165 and 190 nm. UV–Vis measurements were employed to examine the optical characteristics of the films. The red shift was observed for 2 at.% Ni content (3.38 eV) while the blue shift was observed for (4–8) at.% Ni content. The wavelength-dependent refractive index and dielectric constant showed anomalous dispersion in the absorption band, representing the transparency of the films. The 4-point probe measurement showed a decreasing trend of resistivity with increasing temperature, whereas the resistivity increased with Ni content. Activation energy indicated a higher amount of adsorbed oxygen in the films due to the high amount of Ni content.

Study on the structural, optical and electrical properties of N-doped Ga2O3 films synthesized by sol-gel method

Ga2O3 exhibits great potential for applications in solar-blind ultraviolet photo detector, high-power electronic devices and solid-state light-emitting due to its ultra-wide band gap and high Baliga figure of merit. Here, Ga2(NxO1-x)3 films with varied nitrogen contents were prepared by the sol-gel technique. XRD analysis reveals that nitrogen doping contributes for growth of greater crystalline and SEM-EDS measurements confirm that the monoclinic crystal structure of Ga2(NxO1-x)3 is maintained to doping level of 3.26wt%; FTIR information indicates that nitrogen prefers to substitute for the O1 and O2 site of Ga2O3; XPS offers evidence that nitrogen tends to occupy oxygen vacancies and generate more gallium vacancies; UV-VIS shows that impurity defects appear above valence band, and the absorption position undergoes a red shift with nitrogen above 1.32wt%; PL shows Ga2(NxO1-x)3 films can emit light of various colors under excitation at 325nm, and the acceptor level is at 1.63eV∼2eV above the valence band; The conductivity of Ga2(NxO1-x)3 films is changed from n-type to p-type when nitrogen-doping is 0.96 wt% and the I–V curve composed of Ga2(NxO1-x)3 and Ga2O3 shows PDCR = 43 under the 254nm light. Therefore, the development of nitrogen-doped β-Ga2O3 has potential opportunities for applications in photoelectric devices.

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).

Magnetic and anomalous Hall effect investigations of co-sputtered Co2MnGa Heusler alloy thin films

The cobalt-based full Heusler alloy Co2MnGa (CMG) is well known for exhibiting an exotic phenomenon such as magnetic Weyl semimetallic nature with a high Curie temperature of ∼700 K and a giant anomalous Hall effect. Here, we report a detailed study of structural, electrical, and magnetic properties of Co2MnGa thin films (thickness in the 40–10 nm range) grown on Si(100) by the direct-current magnetron co-sputtering technique using Co and MnGa targets. Structural analysis of the samples revealed the polycrystalline nature of these films with B2 type structural ordering. The damping parameter decreases with the increase in film thickness and reaches the minimum value of 6.1 × 10−3 for a 40 nm thin CMG film. These CMG films are magnetically isotropic and soft ferromagnetic in nature. A remarkably high value of anomalous Hall conductivity (AHC) of 1920 S/cm (2 K) is found for the 40 nm thin film, which is comparable to earlier reported values on highly ordered CMG films. Nearly 73% of this AHC value originates from the intrinsic contribution. The AHC and longitudinal conductivity both increase with the film thickness. Different scaling mechanisms are used to compute the intrinsic and extrinsic contributions playing a role in AHC. The analysis of advanced scaling [by Tian et al., Phys. Rev. Lett. 103, 1–4 (2009)] performed on these CMG films suggests the consistency in the enhanced intrinsic AHC value irrespective of the thickness and a decrease in skew scattering contribution with thickness. These results will enhance the understanding about the magnetic and transport properties of Co2MnGa thin films of different thicknesses and suggest it to be a promising material for topospintronic applications.

Comprehensive investigation of sputtering deposition pressure effects on a-InGaZnO Schottky diodes

The effects of Ar sputtering deposition pressure on the optical, structural, morphological, and electrical properties of amorphous InGaZnO thin films were investigated. The InGaZnO thin films, which have amorphous structures determined by grazing incidence x-ray diffraction, contained In, Ga, Zn, and O confirmed by secondary ion mass spectrometry method. Additionally, when the thicknesses of the deposited thin films are examined, it was seen that the profilometer measurement results of the crater formed by secondary ion mass spectrometer and scanning electron microscope measurement results are nearly similar, and it is approximately 100 nm. The surface roughness, obtained from Atomic Force Microscopy results, show that decreased up to a particular value with the increase of the working pressure, and then the surface roughness increased. The optical band gaps of the films were obtained in the range of 3.50 eV−3.58 eV via Tauc relation by using the Ultraviolet-Visible measurements carried out in the wavelength range of 200 nm−1100 nm. It was seen that the optical band gap was decreased with the increase in Ar pressure. The electrical properties of InGaZnO thin film-based Schottky diodes, such as the barrier height, ideality factor, saturation current, series resistance, and shunt resistance, have also been studied comprehensively. The electrical results showed that diode properties change with increasing deposition pressure.

Epitaxial Growth of Cobalt Oxide Thin Films on Sapphire Substrates Using Atmospheric Pressure Mist Chemical Vapor Deposition

This study demonstrated the epitaxial growth of single-phase (111) CoO and (111) Co3O4 thin films on a-plane sapphire substrates using an atmospheric pressure mist chemical vapor deposition (mist-CVD) process. The phase structure of the grown cobalt oxide films was manipulated by controlling the growth temperature and process ambient, confirmed through X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Furthermore, the electrical properties of Co3O4 films were significantly improved after thermal annealing in oxygen ambient, exhibiting a stable p-type conductivity with an electrical resistivity of 8.35 Ohm cm and a carrier concentration of 4.19 × 1016 cm−3. While annealing CoO in oxygen atmosphere, the Co3O4 films were found to be most readily formed on the CoO surface due to the oxidation reaction. The orientation of the atomic arrangement of formed Co3O4 was epitaxially constrained by the underlying CoO epitaxial layer. The oxidation of CoO to Co3O4 was largely driven by outward diffusion of cobalt cations, resulting in the formation of pores in the interior of formed Co3O4 films.

Effect of Ruthenium doping in tailoring structure, optical and electrical properties of Sb2S3 thin film synthesized via electrodeposition technique

Effect of Ruthenium doping in tailoring structure, optical and electrical properties of Sb2S3 thin film synthesized via electrodeposition technique

Plasma power effect on crystallinity and density of AlN films deposited by plasma enhanced atomic layer deposition

Aluminum nitride (AlN) film is a promising material which is used in various fields. In this study, AlN films with different plasma powers were grown by remote plasma atomic layer deposition. Saturation experiments have been applied in the plasma power between 1000 and 3000 W. The influence of plasma power on preferential orientation, chemical, optical, and electrical properties of AlN films are investigated. AlN films displayed multiphase hexagonal wurtzite crystal structure with (002) preferential orientation for higher plasma power, while the predominant orientation shifted toward (100) at lower plasma power. The optical emission spectroscopy analyses show that NH and NH2 radicals conduce to the deposition of AlN films and H radicals selectively dissociate Al–OH bonds which were on AlN film surface and etch deposition films. Atomic force microscopy measurements show that the 1500 W prepared AlN film with smallest surface roughness may be related to the relatively smaller concomitant crystal grains of (100) and (002). X-ray photoelectron spectroscopy investigation presents that oxygen content decreases as the plasma power increases. The obtained maximum value of dielectric constant and breakdown electrical field of AlN film deposited at 3000 W is 8.23 and 5.42 MV/cm, respectively.

Effect of oxygen and nitrogen sensitization on structural, optical and electrical properties of PbSe thin films

An effective two-step sensitization technique was implemented in PbSe thin films, leading to a remarkable improvement in the optoelectronic performance of PbSe photodetectors. The phase composition, surface and cross-sectional morphology, temperature-dependent carrier concentration and mobility as well as the detectability of PbSe films after sensitization were systematically investigated using characteristic techniques. The optimal PbSe film oxygen sensitized at 450 °C exhibited a room-temperature photodetection with a carrier concentration of 5.31 × 1016 cm−3, carrier mobility of 16.52 cm2/V−1s−1, and detectivity of 2.25 × 109 Jones. High-temperature argon heat treatment and oxygen sensitization of PbSe films are expected to suppress recombination losses and significantly improve the optoelectronic properties of sensitized PbSe films due to enhanced carrier separation and transport. The enhanced photoresponse mechanism of the PbSe films through two-step sensitization method was also discussed. These results suggest that the proposed method can be applied to high-performance lead selenide photodetectors.

Influence of Aluminium on the Structure and Electrical Properties of Amorphous Diamond-Like Silicon-Carbon Films

Influence of Aluminium on the Structure and Electrical Properties of Amorphous Diamond-Like Silicon-Carbon Films

Reduced leakage current in atomic-layer-deposited HfO2 thin films deposited at low temperature by in-situ defect passivation

HfO2 films grown via atomic layer deposition (ALD) at low temperature generally exhibit high impurity content, reduced density, and increased oxygen defects, resulting in degraded electrical properties. To overcome this issue, this study applied an in-situ defect passivation technique at low temperature, modifying the ALD oxygen source feeding step to suit heat-sensitive substrates. The electrical properties of the ALD HfO2 film grown at 80 °C are improved when the oxygen source feeding step is repeated twice, and especially the leakage current density is significantly decreased, which is approximately 1/7 smaller at an electric field of 1 MV/cm compared to the film grown via the conventional ALD process at 80 °C. This improvement in the electrical properties can be attributed to decreased carbon impurities and oxygen defects and increased film density. A simple modification of the oxygen source feeding step during the ALD process can effectively reduce defects within the ALD HfO2 films at the atomic layer level, even when grown at low deposition temperatures.

Zirconium doped zinc oxide thin films grown by spray pyrolysis technique for TCO applications

Zirconium (Zr) doped Zinc Oxide (ZnO) thin films were grown on pre-cleaned glass substrates by spray pyrolysis technique. The dopant was added in different concentrations to study its influence on the structural, optical, morphological, and electrical properties of ZnO thin films. X- Ray Diffractogram (XRD) data was used to study the structural properties of all the thin films. It was found that the crystallite size varied between 25 and 45 nm for dopant at different concentrations. Additionally, it was discovered that ZnO possessed a hexagonal wurtzite structure with (002) as its preferred orientation regardless of the doping doses. The optical properties for all the thin films were obtained by analysing the absorption spectra. The transmittance of all the thin films ranged between 65 % and 86 % in the visible range with 4 at % Zr doped ZnO having highest transmittance. Scanning Electron Microscopy (SEM) results showed the agglomeration of particles at higher concentrations of the dopant. Electrical studies showed that the resistivity of the doped samples decreased as compared to the pristine sample. Sample with 6 % of doping had the highest carrier concentration and hence, showed the least resistivity of 67 Ω cm.

Influence of the Gas Preheating Temperature on the Microstructure and Electrical Resistivity of Copper Thin Films Prepared via Vacuum Cold Spraying

Vacuum cold spraying (VCS) has emerged as an environmentally sustainable method for fabricating ceramic and metal films. A high particle impact velocity is a critical factor in the deposition of metal particles during the VCS process, which can be significantly enhanced through gas preheating. This study employs Computational Fluid Dynamics (CFD) simulations to investigate the substantial impact of gas preheating temperature on particle impact velocity and temperature. Elevating the gas temperature leads to higher particle impact velocity, resulting in severe deformation and the formation of dense copper films. The experimental results indicate improvements in both film compactness and electrical properties with gas preheating. Remarkably, the electrical resistivity of the copper film deposited at a gas preheating temperature of 350 °C was measured at 4.4 × 10−8 Ω·m. This study also examines the evolution of cone-shaped pits on the surface of copper films prepared on rough substrates. VCS demonstrates a self-adaptive repair mechanism when depositing metal films onto rough ceramic substrates, making it a promising method for ceramic surface metallization.

Ca-Doped Copper (I) Oxide Deposited via the Spray Coating Technique for Heterojunction Solar Cell Application

In this report, the morphological, optical, electrical, and photovoltaic properties of copper oxide and calcium-doped copper oxide thin films produced via the spray coating method were studied. The thermal post treatment at 300 °C in an inert atmosphere allowed us to obtain a single phase of Cu2O with 21 Ωcm of resistivity (ρ). In this study, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, and 10 wt% Ca admixtures with copper oxide were investigated. The determined optimal calcium dopant concentration was 4 wt%. XRD analysis was used to reveal the chemical composition of the produced layers. It was found that a calcium dopant does not change the layer composition but improves its electrical parameters. Based on UV-Vis spectra, the band gap energy and Urbach energy were calculated. The morphology of produced thin films was described as smooth and nanocrystalline, corresponding to a grain size calculated based on the Scherrer equation. Finally, it was shown that the developed protocol of low-resistivity copper oxide deposition via the spray coating technique can be successfully implemented in heterojunction solar cell production. The I–V parameters of Ag/n-type CzSi/REF:CuOx and 4Ca:CuOx/Carbon were collected, and the achieved efficiency was 2.38%.

Effective of l-tyrosine hydrochloride on the photovoltaic performance of tin-based perovskite solar cells by suppressing tin (II) oxidation

Additive engineering has been widely concerned to improve the photovoltaic performance of tin-based perovskite solar cells (PSCs). Here, the tin-based perovskite precursor solution is modified with L-Tyrosine hydrochloride (LTHCl). The results demonstrate that the defect state density of tin-based perovskite films is reduced by improving their morphology and crystallinity. The electrical properties of tin-based perovskite film are enhanced by suppressing the Sn2+ oxidation. As a result, the open-circuit voltage of tin-based PSCs is increased from 0.53 V to 0.59 V. The best power conversion efficiency of the tin-based PSC with LTHCl is up to 8.63 %, which is higher than that of the pristine device (7.65 %). Meanwhile, the tin-based PSC with LTHCl retains 84 % of its initial efficiency after over 1140 h in a nitrogen glove box.

Annealing-free fabrication of high-quality indium tin oxide films for free-carrier-based hybrid metal–semiconductor nanophotonics

Recent discoveries have revealed that indium tin oxide (ITO), due to the presence of an epsilon-near-zero (ENZ) point and suitable carrier concentration and mobility, can be used to modulate the refractive index, confine fields in the nanoscale, enhance nonlinear effects, achieve ultrafast light switching or to construct so-called time-varying media. While this potential positions ITO as a key material for future nanophotonic devices, producing ITO films with precisely engineered properties remains a significant challenge. Especially when the device’s complex geometry or incorporated materials require the fabrication process to be conducted at substrate temperatures below 100 °C and without any post-annealing treatment. Here we present a comprehensive study on the low-temperature deposition of 70 nm thick ITO films using an e-beam PVD system. The nanolayers evaporated under different conditions were characterized by SEM and AFM microscopy, Hall effect measurement system as well as spectroscopic ellipsometry. We discuss the factors influencing the optical, electrical, and morphological properties of ITO films. We show that smooth nanolayers of similar quality to annealed samples can be obtained at 80 °C by controlling the oxygen plasma parameters, and the ENZ wavelength can be tuned throughout the NIR spectral range. Finally, we show that using the proposed methodology, we fabricated ITO films with resistivity as low as 5.2 × 10–4 Ω cm, smooth surface with RMS < 1 nm, high carrier concentration reaching 1.2 × 1021 cm−3 and high transmittance (85%) in the Vis/NIR spectrum.

Sputter epitaxy and characterization of manganese-doped indium tin oxide films with different crystallographic orientations

Epitaxial Mn-doped indium tin oxide (ITO) films were deposited on single-crystal yttria stabilized zirconia (YSZ) substrates with (111), (110), and (100) crystal plane orientations using RF magnetron sputtering. The epitaxial relationship between the Mn-doped ITO films and the YSZ substrates was studied using x-ray diffraction (XRD) patterns in the ω–2θ scan mode and XRD pole figures. The Mn-doped ITO films on the YSZ(111) and YSZ(110) substrates exhibited a higher degree of crystallinity than the film on the YSZ(100) substrate as per the x-ray rocking curves. Fluctuations in the crystalline alignment were found to significantly influence the electrical properties of Mn-doped ITO films. Ferromagnetic hysteresis loops were observed at room temperature for all the epitaxial Mn-doped ITO films, irrespective of their crystallographic orientation. The magnetic properties of the epitaxial Mn-doped ITO films suggest that a combination of delocalized charge carrier-mediated interaction and bound magnetic polaron-driven interaction is required to explain the origin of ferromagnetism in these films. The Mn-doped ITO film on the YSZ(111) substrate exhibited the most desirable characteristics in terms of crystallinity, surface smoothness, electrical conductivity, and magnetic properties.