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Effect of Substrate Temperature on Properties of Nickel Oxide (NiO) Thin Films by Spray Pyrolysis
摘要： NiO thin films were deposited on a glass substrate and investigated for the physical properties optimized through substrate temperature (350–390°C) using a spray pyrolysis technique. The effect of substrate temperature on deposited NiO thin film was studied by thermogravimetric analysis and differential thermal analysis, X-diffraction (XRD), field electron scanning electron microscopy, optical absorption and electrical measurement techniques. XRD analysis indicates that NiO thin films are of a polycrystalline cubic structure. Optical properties are calculated with help of transmittance and absorbance data in the wavelength range between 200 nm and 900 nm. The optical band gap energy values increased from 3.1 eV to 4.0 eV with substrate temperature. Further, the extinction coefficient, refractive index, and real and imaginary parts of dielectric constant and optical conductivities of NiO thin films were calculated. The electrical resistivity measurement shows conductivity of the NiO thin film increased with increase in substrate temperature.
关键词： composition,spray,semiconducting behavior,electrical properties,NiO
更新于2025-10-22 19:40:53
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Temperature-Dependent Electrical Characteristics of β-Ga <sub/>2</sub> O <sub/>3</sub> Diodes with W Schottky Contacts up to 500°C
摘要： The development of thermally stable contacts capable of high temperature operation are necessary for Ga2O3 high power rectifiers. We have measured the electrical characteristics of sputter-deposited W Schottky contacts with Au overlayers for reducing sheet resistance on n-type Ga2O3 before and after device operation up to 500°C. Assuming thermionic emission is dominant, the extracted barrier height decreases with measurement temperature from 0.97 eV (25°C) to 0.39 eV (500°C) while showing little change from its initial value of 0.97 eV after cooling down from each respective operation temperature. The room temperature value is comparable to that obtained by determining the energy difference between binding energy of the Ga 3d core level and the valence band of the Ga2O3 when W is present, 0.80 ± 0.2 eV in this case. The Richardson constant was 54.05 A.cm?2.K?2 for W and the effective Schottky barrier height at zero bias (eφb0) was 0.92 eV from temperature-dependent current-voltage characteristics. The temperature coefficient for reverse breakdown voltage was 0.16 V/K for W/Au and 0.12 V/K for Ni/Au. The W-based contacts are more thermally stable than conventional Ni-based Schottkies on Ga2O3 but do show evidence of Ga migration through the contact after 500°C device operation.
关键词： electrical characteristics,thermal stability,high temperature operation,Ga2O3,Schottky contacts
更新于2025-09-23 15:23:52
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Synthesis, Conductivity and Impedance Studies on across adjacent ring formed new metallo phthalocyanines
摘要： The synthesis and characterization of Co(II), Zn(II) and Ni(II) phthalocyanines (Pcs) 4, 5 and 6, respectively containing two Bis[2-(4-hydroxyphenyl)-2-propyl]benzene across adjacent ring formed at the peripheral positions are described. The Pcs were synthesized by cyclotetramerization of the previously prepared precursor 4,4’-bis[1,3-propylbenzene-2-p-phenoxy]phthalonitrile (3) with the presence of metal salt in boiling dry DMF under a dry nitrogen atmosphere. Elemental analysis, UV-Vis, FT-IR, MALDI-TOF mass and 1H-NMR spectrometry techniques were used for characterization of 4. DC and ac conductivity and impedance spectra (IS) measurements were performed on the films 5, and 6 between the temperatures 293 - 523 K and frequencies 40-100 kHz. The dc conductivity values were calculated as 2.11x10-10 S/cm, 3.48x10-10 S/cm, and 1.90x10-10 S/cm for the films of 4, 5, and 6 at room temperature. Activation energy values of the films were also calculated. ac conductivity results suggest that dominant charge transport mechanisms can be explained by hopping model depending on temperature and frequency range. From impedance spectra, Cole-Cole plots, the relaxation time in Debye dispersion relation is considered as a distribution of relaxation time values, rather than as a single relaxation time. To elucidate the structural, spectroscopic and bonding properties of the obtained compounds, DFT/TD-DFT calculations were performed.
关键词： Density functional theory,Conductivity,Electrical characterization,Impedance spectra,Metallophthalocyanine,Hopping
更新于2025-09-23 15:23:52
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Variation in Structural, Electrical and Optical Properties of Selenium Nanowires After Irradiation with Ni6+ Ions
摘要： The effect of Ni ion irradiation on selenium nanowires of 80 nm diameter is studied in the present work. Se nanowires were prepared by using electrodeposition technique in polycarbonate membrane. Changes in the structural, optical and electrical properties are studied using XRD, UV/Vis spectroscopy and current–voltage characteristics, of the pristine and irradiated samples. X-ray diffraction study confirms the variation in peak intensity without any shifting in peak position. Variation in texture coefficient and grain size was clearly observed which is a consequence of changing plane orientation, irradiation induced grain growth and grain fragmentation. A decrease in the optical band gap takes place due to interstitial energy band states in the vicinity of conduction and valence band. IVC also shows variation in the conductivity which is due to the generation of current carriers with the passage of energetic ions.
关键词： Ion irradiation,Optical analysis,Selenium nanowires,Impedance,Electrical properties,Structural analysis
更新于2025-09-23 15:23:52
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Elaboration of a Conductive Textile by Coating for Clothes Equipped with Fourth-Generation Photovoltaic Cells
摘要： Conducting polymer coated in textiles possess a wide range of electrical properties. The surface resistivity is influenced by concentrations of the reactants, thickness of the coating, nature of the substrate surface, extent of penetration of the polymer into the textile structure and the strength of the binding of the coating to the textile surface. Low resistivity in fabric results from highly doped thicker coatings that penetrate well into the textile structure thus enabling good electrical contact between fibers. In this study, we had chosen copper as conductor polymer for coating. The electrical conductivity is influenced by the thickness of coating paste, the nature of the substrate surface. The thickness of the paste and the concentration of the copper were studied in this paper. Furthermore, the electrical surface resistance decreased from 68 MΩ to 8 MΩ with decreasing in coating thickness. However, the thickness of coated fabric is very important factor to determine conductivity and application of textile. In addition, we had noticed that the airflow is affected by the coating thickness which the penetration of the airflow differs from the lower thickness to the higher one. This study confirm that we can use coating woven fabric to develop a textile substrate responding to characteristics such as electrical resistance, drapability, air permeability and tensile strength, which are particularly important to be used as a support for flexible photovoltaic cells in clothes.
关键词： Conductor textile,Technical textile,Coating,Electrical resistance
更新于2025-09-23 15:23:52
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Fe doping effect of vanadium oxide films for enhanced switching electrochromic performances
摘要： In the present study, Fe-doped V2O5 films showing impressive electrochromic (EC) performance were developed using the sol-gel spin-coating method. To confirm the optimized Fe-doping effect on the V2O5 films for the EC performance, we adjusted the Fe atomic percentages to 0.0, 0.5, 1.0, and 1.5 at%, respectively. With the effect of Fe doping on the V2O5 films, the obtained films resulted in the formation of the oxygen vacancies. As the result, when the optimum Fe atomic percentage was 1.0 at%, the enhanced switching speeds (3.7 s for the bleaching speed and 2.0 s for the coloration speed) and enhanced coloration efficiency value (47.3 cm2/C) compared to the other films were implemented. This can be attributed to the improved electrical conductivity and Li+ diffusion coefficient that led to efficient generation of the EC reaction activity and narrowing the optical bandgap at the coloration state to increase transmittance modulation. Therefore, this unique film can be a promising EC material to improve the performance for the EC devices.
关键词： Films,Optical properties,Transition metal oxides,Electrical properties,Electrochromic performances
更新于2025-09-23 15:23:52
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IRT image segmentation and enhancement using FCM-MALO approach
摘要： Infrared Thermography (IRT) is a method that has modernized the way for monitoring the thermal conditions, finding some potential faults or defects that could be available in electrical systems. In the proposed work, IRT electrical images are taken for diagnosing the faults by the image pre-processing and segmentation process. Initially, the IRT images are changed over into a grayscale image, trailed by image pre-processing is performed where histogram equalization is applied. With the intention of segmenting the faulty portion (high temperature zone) from the electrical equipment, Fuzzy C Means (FCM) strategy is introduced. For optimizing the centroid of FCM algorithm Modified Ant Lion Optimization (MALO) is proposed. From the segmented images, small size portions are removed by using Region Props function. This operation can remove the isolated pixels from the image and extract image components for better representation of images. The optimum results show that the proposed work accomplishes maximum segmentation accuracy compared to existing segmentation algorithms.
关键词： Pre-processing,Infrared thermography images,Fault diagnosis,Segmentation,Region props function,Electrical equipment
更新于2025-09-23 15:23:52
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Understanding structure, optical, and electrical properties of In4Sn3O12 and In4.5Sn2M0.5O12 (M?=?Nb and Ta)
摘要： The current research aims to investigate transparent conducting properties of In4Sn3O12 related compounds. Undoped and M-doped In4Sn3O12 with the formula In4+xSn3-2xMxO12 (Mx = Nb0.5 and Ta0.5) have been successfully synthesized by solid state reaction as confirmed by powder X-ray diffraction. Interestingly, only the composition with x = 0.5 could be achieved without impurity. The oxidation states of all elements were identified by X-ray photoelectron spectroscopy to be In3+, Sn4+, Nb5+, and Ta5+. The larger optical band gap energies were obtained in doped samples, which agree with the results from DFT calculations. Although the conductivity of In4Sn3O12 is relatively high, those of In4.5Sn2Nb0.5O12 and In4.5Sn2Ta0.5O12 are much lower. To investigate the conduction mechanism, the conductivity of the samples after heat treatment in N2 was studied. The improved conductivity after such annealing along with the results from X-ray photoelectron spectroscopy suggest that the major charge carriers are electrons created from oxygen vacancies in the lattice. The results from computational calculations indicate that Nb, Ta, and for comparison, Sb substitutions do not significantly change the band structure nor the carrier mobility. However, Sb could lower the oxygen vacancy formation energy which might be the reason of lower resistivity in Sb substituted In4Sn3O12. Besides the oxygen vacancy formation energy, the nature of donor states is important in determining the electrical conduction in the samples.
关键词： DFT calculation,Oxides,Electrical properties,Optical properties
更新于2025-09-23 15:23:52
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Reinforcing effect of amine-functionalized and carboxylated porous graphene on toughness, thermal stability, and electrical conductivity of epoxy-based nanocomposites
摘要： Epoxy-based nanocomposites reinforced with nonfunctionalized porous graphene (NPG), carboxylated porous graphene (CNPG), and amine-functionalized porous graphene (ANPG) were investigated with regard to mechanical properties, thermal stability, and electrical conductivity. Nanomaterials were added to the epoxy matrix in varying contents of 0.5, 1, and 2 wt %. Generally, mechanical properties were improved as a result of introducing nanomaterials into the epoxy resin. However, the amelioration of toughness was only observed in functionalized NPGs/epoxy nanocomposites. Field emission scanning electron microscopy images showed that functionalized nanomaterials induced a rougher fracture surface compared to the neat epoxy. Dynamic mechanical analysis along with differential scanning calorimetry confirmed an increment in the glass-transition temperature (Tg) of the reinforced nanocomposites. Also, they proved that functionalization made the epoxy network tougher and more flexible. The electrical conductivity and thermal stability of the epoxy resin were also improved when loaded with nanomaterials.
关键词： toughness,electrical properties,thermal properties,nanocomposites
更新于2025-09-23 15:23:52
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Spatially Uniform Shallow Trap Distribution in an Ultrathin Organic Transistor
摘要： In organic electronic materials, charge carrier transport is often limited by disorder-induced trap states very close in energy to the ideal band transport states. We directly view the location and impact of these 'shallow' traps on an ultrathin transistor active layer using Kelvin Probe Force Microscopy. As the transistor turns on, dramatic fluctuations in the surface potential of the active channel suddenly arise due to charge trapping and release processes. Importantly, the spatial distribution of rapid fluctuations in surface potential is uniform throughout the active channel. These facts strongly constrain the microscopic origin of shallow charge traps, and associated efforts to optimize the mobility and noise performance baseline in device applications.
关键词： disorder,charge traps,electrical noise,organic electronics
更新于2025-09-23 15:23:52