Analogy between electrical and structural properties of electron-beam-deposited SnO 2

A new transition metal-tellurite glass family: Electrical and structural properties

The thickness dependent electrical, structural, and optical properties of ZnO films grown by atomic layer deposition (ALD) at various growth temperatures were investigated. In order to deposit ZnO films, diethylzinc and deionized water were used as metal precursor and reactant, respectively. ALD process window was found at the growth temperature range from <TEX>$150^{\circ}C$</TEX> to <TEX>$250^{\circ}C$</TEX> with a growth rate of about <TEX>$1.7{\AA}/cycle$</TEX>. The electrical properties were studied by using van der Pauw method with Hall effect measurement. The structural and optical properties of ZnO films were analyzed by using X-ray diffraction, field emission scanning electron microscopy, and UV-visible spectrometry as a function of thickness values of ZnO films, which were selected by the lowest electrical resistivity. Finally, the figure of merit of ZnO films could be estimated as a function of the film thickness. As a result, this investigation of thickness dependent electrical, structural, and optical properties of ZnO films can provide proper information when applying to optoelectronic devices, such as organic light-emitting diodes and solar cells.

Ferrites with compositional expression as X. Fe2O4 where X is any dopant (mono, divalent and trivalent ion) are a class of materials which are semiconductors in nature and can also be easily magnetized, acquiring excellent electrical and magnetic properties. Ferrites comprise iron oxide (Fe2O3) in combination with chemically balanced dopants and possess high chemical stability, high Curie temperature, tunable shape and particle size. Ferrites are mainly categorized into soft, hard and mixed ferrites, and due to their superior properties, they can be used as inductors, transformers, electronic absorbers, sensors, etc. The application can also be extended to biomedical, waste water management and in catalysis, etc. Applications are mainly dependent on properties which are tailored to match the operational aspects of ferrites, and this further depends on the dopants used while synthesis. The dopants are selected based on the valency, ionic size, crystal structure, melting point, and magnetic moment and upon doping optimize magnetic and electrical properties. Along with the nature of dopants, the structural properties such as density, Curie temperature and porosity can be modified by selecting different synthesis routes and sintering techniques/conditions.

Photoelectrochemical properties of hematite thin films grown by MW-CBD

The combined effects of the deposition temperature and a hydrogen post-annealing treatment on the structural, electrical, and optical properties of Ga-doped ZnO (GZO) films were investigated as a potential substitute for indium tin oxide transparent conductive oxide (TCO). On the as-deposited films, increasing the deposition temperature initially improved the electrical properties, but a deposition temperature in excess of 423 K resulted in the deterioration of the electrical properties due to the development of ZnGa2O4 and Ga2O3 phases originating from the excessive amount of the Ga dopant. While a post-annealing treatment of the GZO films in hydrogen leveled off the overall properties, improvement in the electrical property was observed only in films initially deposited at room temperature. This is attributed to the excessively high concentration of the dopant Ga released from ZnGa2O4 and Ga2O3 during the post-annealing treatment. It is therefore suggested that in the preparation of TCOs based on GZO films, the concentration of the dopant Ga should be carefully controlled to obtain the optimal properties by suppressing the formation of ZnGa2O4 and Ga2O3 that occurs due to the presence of excess Ga.

Effect of crystalline structure on optical and electrical properties of IWOH films fabricated by low-damage reactive plasma deposition at room temperature

【Sb-doped $SnO_2$ (ATO) thin films were prepared using electrospinning. To investigate the optimum properties of the electrospun ATO thin films, the deposition numbers of the ATO nanofibers(NFs) were controlled to levels of 1, 2, 4, and 6. Together with the different levels of deposition number, the structural, chemical, morphological, electrical, and optical properties of the nanofibers were investigated. As the deposition number of the ATO NFs increased, the thickness of the ATO thin films increased and the film surfaces were gradually densified, which affected the electrical properties of the ATO thin films. 6 levels of the ATO thin film exhibited superior electrical properties due to the improved carrier concentration and Hall mobility resulting from the increased thickness and surface densification. Also, the thickness of the samples had an effect on the optical properties of the ATO thin films. The ATO thin films with 6 deposited levels displayed the lowest transmittance and highest haze. Therefore, the figure of merit(FOM) considering the electrical and optical properties showed the best value for ATO thin films with 4 deposited levels.】

In this work, the structural, electrical, and optical properties of bilayer SiX (X= N, P, As, and Sb) are studied using density functional theory. Five different stacking orders are considered for every compound and their structural properties are presented. The band structure of these materials demonstrates that they are indirect semiconductors. The out-of-plane strain has been applied to tune the bandgap and its electrical properties. The bandgap increases with tensile strain, whereas, compressive strain leads to semiconductor-to-metal transition. The sensitivity of the bandgap to the pressure is investigated and bilayer SiSb demonstrates the highest bandgap sensitivity to the pressure. These structures exhibit Mexican hat-like valence band dispersion that can be approved by a singularity in the density of states (DOS). The Mexican-hat coefficient can be tuned by out-of-plane strain. Optical absorption of these compounds shows that the second and lower valence bands due to the high DOS display a higher contribution to optical transitions.

Unveiling structural and optical properties of Sn-doped β-Ga2O3: A correlation of experimental and theoretical observations

Polymeric foams are one of the new candidates for use in the dielectric layer of coaxial cables to improve their piezoelectric and electrical properties. These properties are affected by the structural properties, which depend on material and processing parameters. In this research study, first, the effect of cell size, cell density, and expansion ratio was theoretically studied on the piezoelectric and electrical properties. Then the effect of talc content, processing temperature, and cooling method was investigated on the structural, piezoelectric, and electrical properties of the produced coaxial cables. The examinations revealed that the increase in cell size, cell density, and expansion ratio increases the piezoelectric coefficient and velocity of propagation and decreases attenuation. According to the analysis of variance results, the talc content parameter was the most effective parameter on cell size, cell density, and piezoelectric coefficient with the contribution of 72%, 83%, and 69%, respectively. Also, the processing temperature parameter was the most effective parameter on the expansion ratio and electrical properties with the contribution of 42%, and 41%, respectively. Finally, the produced sample with talc content of 2 wt%, processing temperature of 125°C, and cooling method by water was introduced as the optimum sample by the multi‐objective optimization. Highlights Production of foamed dielectric layers in extrusion process of coaxial cables. Effect of cell structure on piezoelectric and electrical properties. Effect of process on structural, piezoelectric and electrical properties. Optimization of structural, piezoelectric, and electrical properties. Optimum conditions: 2 wt% of talc, temperature of 125°C, and water cooling.

Effect of substrate temperature and annealing treatment on the electrical and optical properties of silver-based multilayer coating electrodes

Perovskite oxide Y3+-doped BaCeO3 (BaCe1-x Y x O3- d: BCY) is a promising material as an electrolyte of solid oxide fuel cells (SOFCs) that operate in the intermediate- temperature (IMT) region. The electrical conductivity of the bulk crystal exhibits a high proton conductivity of ~7.0×10-2 S·cm-1 at 800 ºC and ~1.0×10-2 S·cm-1at 400 ºC in a wet atmosphere. The proton adsorption and conduction mechanisms have been extensively studied by theoretical and experimental approaches. In order to realize hydrogen separation membranes for hydrogen production in the high-temperature region, Matsumoto and co-workers have developed a Ru5+-doped BCY (BCRY) ceramic that exhibits the electron-proton mixed conduction in moist reducing atmosphere at approximately 800 ºC. When the Ru5+ concentration is in the range of 5~10 mol%, BCRY ceramics exhibit the mixed conduction of 3.0~6.0×10-3 S·cm-1. Although such a mixed conductor can be used as an anode electrode of SOFCs, BCRY thin films have not been realized thus far. Therefore, understanding of the detailed electrical and structural properties of BCRY thin films is most important for the material design of SOFC electrodes. In this study, we present the structural and electrical properties at the surface and bulk regions of BCRY thin films and discuss the role of Ru5+substitution in terms of electron structure. The BCRY thin film was deposited on Al2O3 and Nb-doped SrTiO3 (Nb-STO) substrates by RF magnetron sputtering. The flow rate of Ar gas, the deposition pressure, and substrate temperature were set at 20 sccm, 5.0×10-3 Torr and 600 ºC, respectively. The film thicknesses were changed between ~100 and ~477 nm. The structural property of the BCRY thin films were characterized as a function of film thickness by powder X-ray diffraction (XRD) analysis. The electrical conductivity was measured by the AC impedance method in dry atmosphere in a temperature region from 200 to 600 ºC. The measurement frequency region was from 0.1 Hz to 32 MHz. In order to probe conducting carriers, the conductivity was measured by changing oxygen gas partial pressure (P O2). The electronic structure was characterized by photoemission spectroscopy (PES) and X-ray absorption spectroscopy (XAS). The energy resolutions of PES and XAS were 100 and 60 meV, respectively, at h n= 700 eV. The a- and c-axes-oriented BaCe0.85Ru0.05Y0.10O3- d thin films have been deposited by RF magnetron sputtering. The thin films have mixed valence states of Ce4+ and Ce3+. The activation energy for the conductivity of film thicker than 200 nm at the surface region and bulk region are 0.26 eV and 0.60 eV, respectively. The thin films exhibit ion conduction at the bulk region and electron-ion mixed conduction at the surface region. Proton conductions are also observed in the surface state and bulk state. The Fermi levels (E F) locate at the middle position in the band gap region, although E F of the BaCe0.90Y0.10O3- d thin films locates on the valence band side. These results indicate that the Ru5+ions and protons act as donor ions in BCRY thin films.

Electrical, optical and structural properties of Al-doped ZnO thin films grown on GaAs(111)B substrates by pulsed laser deposition

In this work, we evaluated the structural, electrical and optical properties of carbon-doped Ge8Sb2Te11 thin films. In a previous work, GeSbTe alloys were doped with different materials in an attempt to improve the thermal stability. Ge8Sb2Te11 and carbon-doped Ge8Sb2Te11 films of 250 nm in thickness were deposited on p-type Si (100) and glass substrates by using a RF magnetron reactive co-sputtering system at room temperature. The fabricated films were annealed in a furnance in the 0 ~ 400°C temperature range. The structural properties were analyzed by using X-ray diffraction (XRD), and the result showed that the carbon-doped Ge8Sb2Te11 had a face-centeredcubic (fcc) crystalline structure and an increased crystallization temperature (Tc). An increase in the Tc leads to thermal stability in the amorphous state. The optical properties were analyzed by using an UV-Vis-IR spectrophotometer, and the result showed an increase in the optical-energy band gap (Eop) in the crystalline materials and an increase in the Eop difference (ΔEop), which is a good effect for reducing the noise in the memory device. The electrical properties were analyzed by using a 4-point probe, which showed an increase in the sheet resistance (Rs) in the amorphous state and the crystalline state, which means a reduced programming current in the memory device.

Autonomic modulation of the cardiac activity plays an important role in the pathogenesis of atrial fibrillation (AF). The aim of this study was to assess the differences in the atrial electrical and structural properties between patients with vagal and sympathetic AF. The study included 30 patients (53 ± 12 years old, male 26) with frequent attacks of symptomatic paroxysmal AF. All cases underwent 24-hour ambulatory Holter monitoring before the catheter ablation. The onset of AF accompanied with an increased HF component and decreased L/H ratio was designated as a vagal type (group 1, n = 12), whereas a decreased HF component and increased L/H ratio was classified as a sympathetic type (group 2, n = 18). Electrical and structural properties were evaluated during the ablation procedure. All patients had AF originating from PVs. There was a higher incidence of non-PV triggers in group 2 patients than that in group 1 (44% vs 8%, P = 0.04). Group 1 had a higher bipolar peak-to-peak voltage and mean DF of the global left atrium (LA), shorter total activation time, and smaller LA volume than group 2, whereas the electrical and structural properties in the right atrium were similar. After a follow-up of 15 ± 7 months, there was a lower incidence of AF recurrence in group 1 than that in group 2 (0% vs 28%, P = 0.02). There are better electrical properties and a smaller LA volume in patients with vagal-type AF. In contrast, the LA substrate is worse, and coexisting non-PV triggers and recurrence following ablation are more prevalent in patients with the sympathetic-type AF.