Linear scanning voltammetric measurement was conducted in the above three-electrode cell, and scanning potential was set from 0 to -1 V (vs. SCE) at 0.005 V/s. The photocurrent density was recorded with 0.1 M acetate buffer solution (50 mL) containing 10 mM pyridine. The calibrated irradiation intensity on the thin film electrode is 100 mW/cm 2 .
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Batteries can be applied to microelectronic and portable devices as power sources [1-3]. Also, many endeavors have been made to develop batteries for high power and energy for electric vehicles [4,5]. Although lithium-ion batteries, among all other batteries, are the most promising type owing to their large energy storage density, commercial lithium-ion batteries contain a flammable liquid electro- lyte, which has induced safety concerns. In order to miti- gate the safety issue, an all-solid-state battery is a viable candidate as it is composed of thin film electrodes and a solid electrolyte. Moreover, the thin film electrode usually is composed of an active material without a binder. Owing to these advantages, many studies have been conducted to fabricate all-solid-state batteries through various methods, such as pulsed laser deposition [6-13], electrostatic spray deposition [14-16], and sputtering deposition [17-26]. Although these methods are very efficient for the prepara- tion of thin film electrodes, they have several disadvan- tages, such as their complex fabrication processes, difficulty in controlling the composition of the thin film, and their low deposition rate.
color changed provides a preliminary indication of the formation of cobalt sulfide thin film as reported from previous literature . Figure 2 shows the morphological structure the growth of cobalt sulfide mesoporous nanoflakes. The similar structure was reported by the previous literature [11, 13]. At the first 5 minutes time deposition, mesoporous nanoflakes is starting to grow but in small amount and not fully covered on FTO surface as shown by Figure 2(a). Whereas, Figure 2(b) indicates the growth of cobalt sulfide nanoflakes and covered the FTO surface. In Figure 2(c), the growth of cobalt sulfide is found to be increased and more compact in comparison to the 10 minutes time electrodeposition. The average thicknesses of flakes also found to be increased from 5 to 15 minutes of deposition time; which are 16 nm, 17 nm and 18 nm. The distribution of cobalt and sulfur elements in the deposited cobalt sulfide thin film is illustrated in SEM images of Figure 2(d). The weight percentage (wt.%) of Co and S were quantified by using energy dispersive X-ray spectroscopy (EDAX). It was found that, when the time deposition increased, the wt. % of Co and S also increased as listed in the Table 2. From the calculated empirical formula, the deposited cobalt sulfide was found to have higher cobalt elements contents. This fact is most probably due to the uncompleted formation of cobalt sulfide deposited.
Abstract Dye-sensitized solar cells (DSSCs) were fabri- cated by using well-crystallized ZnO nanocombs directly grown onto the fluorine-doped tin oxide (FTO) via non- catalytic thermal evaporation process. The thin films of as- grown ZnO nanocombs were used as photoanode materials to fabricate the DSSCs, which exhibited an overall light to electricity conversion efficiency of 0.68% with a fill factor of 34%, short-circuit current of 3.14 mA/cm 2 , and open- circuit voltage of 0.671 V. To the best of our knowledge, this is first report in which thin film of ZnO nanocombs was used as photoanode materials to fabricate the DSSCs. Keywords ZnO Nanocombs
In this paper we report alumina based capacitive humidity sensor having ex- ceptional sensing performance in wide range RH segment (10% - 90%). The developed sensor has an improvement of accuracy, reliability, and economic efficiency; apart from fast response and recovery time ( ∼ s), negligible baseline drift and high selectivity for moisture. The sensing mechanism was discussed based on their microstructures, such as surface area and mesopore volume. In general, at low humidity, surface area and water adsorption play the domi- nant role, while at high humidity, mesopore volume and capillary condensa- tion become important. Standard characterization techniques such as AFM, FESEM, BET, XRD and impedance spectroscopy were employed for mi- cro-structural and electrical characterization of RH sensor. The nano porous alumina film undergoes a huge change in dielectric upon adsorption of moisture, ensuing large change in capacitance. Additionally, a prototype RH meter has been developed with digital readout for humidity. The interface circuit was based on capacitor-to-duty cycle (CDC) converter. The proposed digital circuit has the advantage of performing adaptive measurements as a function of resolution and bandwidth. The prototype instrument can be used for sub ppm level moisture detection where stability and response are com- pletely unaffected even in highly toxic ambience viz. 4% ammonia and 4% chlorine.
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new fabrication method based on solvent drying with a halide-free lead precursor controlling the crystallization atmosphere. Here, the reaction of the precursors yields liquid organic by- products at RT which enable large crystal growth with perfectly oriented crystal planes parallel to the substrate as shown by GIWAXS measurements. Our results show that large crystal sizes can only be achieved for smooth ITO substrates, whereas perovskite films on FTO result in crystals limited to hundreds of nanometers due to the enhanced surface roughness which limits horizontal growth. Also, we examined the role of perovskite crystallite orientation in planar heterojunction solar cells by comparing non-oriented VASP-derived films with our newly developed oriented CSD-derived films. We show that this perfect alignment of the cubic crystal planes parallel to the substrate of the CSD-derived film leads to a reproducible and high device performance. Additionally, we show enhanced short circuit currents approaching 7 mA cm -2 ,
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Aluminium in a Cu-Mo-Al thin film generated on an indium tin oxide (ITO) glass substrate in an aqueous solution by a rectangular pulse current technique in a range of frequency from 0.2 to 1.5 MHz was demonstrated. The aluminium concentration in the Cu-Mo-Al thin film measured with energy dispersive X-ray spectroscopy (EDX) was observed only in the vicinity of a resonant frequency. Several resonant frequencies existed at a certain interval in the range of the frequency. The resonant frequency spacing between the neighboring resonant frequencies became about 0.2 MHz. These experimental results are discussed from a viewpoint of energy level transition between the Fermi energy of electron in an electrode and a quantized rotational energy of a cluster of a trivalent aluminium ion and divalent molybdate ion. The maximum aluminium concentration in the Cu-Mo-Al thin film was about 6 wt. %. X-ray diffraction (XRD) analysis showed that (111), (200), (220), and (311) planes well consistent with those of polycrystalline copper existed parallel to the ITO glass. The Cu-Mo-Al thin film is found to be an alloy comprising Cu, Mo, and Al. In addition, surface images of the Cu-Mo-Al thin film observed with scanning electron microscope (SEM) showed an aggregation of nano cauliflowers.
47906, USA) was polished with alumina (BAS, PK-4). Then the GCE with the reference and the auxiliary elec- trode was mounted with the help of a Teflon holder in a voltammetric cell containing 1 mL of mercury (II) ni- trate solution, 1 mL of 10 −1 mol·L −1 potassium nitrate solution and 8 mL of purified water. The solution in the cell was purged with nitrogen for 240 s to eliminate the oxygen present. The mercury plating on the surface of GCE was carried over for five minutes at −0.9 V. After a visual check that the mercury film was well done on the surface of GCE, it was rinsed with pure water along with the reference and the auxiliary electrode. Finally, the electrodes were properly engaged in the Teflon holder under a new and clean voltammetric cell containing only solutions with the NaOH electrolyte or already containing hypoxanthine.
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Main materials in this study are 25, 26, 27, 28- tetrahydrocalixarene (C4) and 49, 50, 51, 52, 53, 54, 55, 56-octahydroxycalixarene (C8) (FIGURE 1) that purchased from Sigma-Aldrich. Each of the calixarenes was dissolved in chloroform (CHCl3) to produce 0.2 mg/ml of calixarene solution. The calixarenes and their organic solvent, CHCl3 (>99.8% purity) were used without additional purification procedure. Pieces of quartz with a dimension of 2.5 cm × 2.5 cm were selected as the substrate for calixarene LB thin film deposition. Proper cleaning method was utilized to ensure the cleanliness of the substrate. Initially, the substrates were cleaned with Decon 90 before rinsed with deionized (DI) water. Later, ultrasonication (40 kHz) of substrates with the sequences of acetone (10 minutes), DI water (2 minutes), propanol (10 minutes) and DI water (2 minutes) again before the drying process with a nitrogen gun take place. Finally, the substrates were being treated hydrophobically with 1,1,1,3,3,3-Hexamethyldisilazane (C 2 H 19 NSi 2 ) overnight to
Abstract: The present work is intended to prepare manganese doped cobalt oxide electrodes on copper and porous copper substrate by electrodeposited technique. Structural, morphological and electrochemical characterizations of the prepared samples were examined by using XRD, SEM, EDAX, FTIR and electrochemical measurements. Structural studies confirm MnCo 3 O 4 Film has face centred cubic (FCC) with polycrystalline nature. Morphological observation of the prepared films
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In this study, a sensitive, label-free amperometric immunosensor based on graphene sheets-methylene blue nanocomposite and gold nanoparticles (GS-MB/GNPs) for the direct determination of chlorpyrifos residues was exploited. To fabricate the immunosensor, GS was first dispersed with chitosan(CS) to obtain a homogeneous solution and then mixed with MB in a ratio of 2:1. The nanocomposite film of GS-MB was dropped on the surface of glassy carbon electrode (GCE) which was first modified by the electrodeposition of GNPs. The stepwise assembly process of electroactive species on electrode surface and the performance of the immunosensor was characterized by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM), respectively. The GS-MB nanocomposite possesses good electrochemical behavior and high binding affinity to the electrode. Furthermore, high surface areas of GS and vast aminos and hydroxyls of CS provide a platform for the crosslinking of antibody. Under optimal conditions, the proposed immunosensor showed a wide linear range from 1 to 500 ng/mL with a detection limit of 0.056ng/mL.The constructed immunosensor exhibited good reproducibility, high specificity, acceptable stability and regeneration performance, which provided a new promising tool for the detection of chlorpyrifos in real samples.
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The cysteic acid modified-glassy carbon electrode, the platinum wire counter electrode, and the saturated calomel reference electrode (SCE) were immersed in 20.00 mL B-R buffer solution (0.04 M, pH 1.81). A certain amount of sinomenine was added in the solution, with stirring by a magnetic stirrer. The stirring was stopped after the electrochemical accumulation for 10 s was at - 0.70 V. Then the differential pulse voltammetry (DPV) was immediately performed to scan from + 0.40 to +1.10 V after quiet time of 20 s. To establish the optimum conditions for the determination of sinomenine by means of the DPV technique, various instrumental parameter variables were studied, and the optimum conditions were as follows: scan rate, 4 mV·s -1 ; sampling width, 0.05 s; pulse amplitude, 50 mV; and
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Si thin film with a thickness of approximately 20 μm. The Si thin film can be bent to almost 180° by tweezers, showing a good flexible characteristic. Actually, the Si films are flexible and bendable when the thickness is less than approximately 50 μm. The inset of Figure 1b shows an optical image of a CNT/Si thin-film solar cell. Because of anisotropic etching, the Si thin films have pyramid-like texture on their surface (Figure 1c), which increases the roughness of the Si surface significantly. However, it is hard to observe such texture under SEM when the Si thin films are covered by CNTs (Figure 1d). It indicates that not all of the CNTs contact with the Si surface and some CNT bundles might bridge over of the pyramid-like peaks of the Si thin films.
The Zn 2+ optimum doping amount is 0.05%, because then the transfer rate of carriers of the fastest, the sepa- ration of electron hole pair efficiency is the highest, the photocatalytic activity is the strongest. When Zn 2+ dop- ing amount is less than 0.05%, the defect levels and impurity levels is separating center of electron-hole pairs; When Zn 2+ doping greater than 0.5%, the defect levels and impurity levels is recombination center of elec- tron-hole pairs. carrier recombination rate accelerated, electron-hole pairs separation efficiency decreases. 3.4. UV-Vis Spectra of Different Concentration Ion Doped TiO 2 Thin Film
strates, which have only a single light-scattering center. From Figure 5b and Table 1, it is evident that the fill factor (FF) of a-Si:H thin-film solar cells on mesoporous patterned ZnO and wet-etched AZO is increased, des- pite the rougher surface of the AZO layer. This can be attributed to the short charge transport path within the cells, in that the thickness of the layer in the direction of the local surface normal is less than in the deposition direction. This shorter charge transport path lowers the series resistance, thus increasing the FF.
functionalities, in accordance with previous reports [30-32]. The functionalisation of the PyC films was confirmed electrochemically, using the Fe 3+/2+ probe. The kinetics of this redox process are known to be strongly influenced by the presence of surface oxides . The upper inset of Fig. 3 shows voltammograms recorded at PyC electrodes before and after etching. The as-grown films show no response to this probe, whereas etched films give rise to ideal voltammograms, indicative of rapid electron transfer. This effect is attributed to the large oxide coverage generated by etching. Also contained in Fig. 3 is a Raman spectrum recorded for an as-grown film. As with other graphitic materials, the primary features are the D and G peaks at 1350 and 1580 cm -1 , respectively. The former is related to defects and disorder, and its prominence is indicative of the nano-crystalline nature of these electrodes. Etching had no effect on the Raman spectrum, despite the considerable change found using XPS. We attribute this to the large penetration (100 nm) of the Raman laser. For such thin films, Raman can be thought of as a bulk technique, whereas XPS only penetrates to 1 nm.
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The requirement of micro miniaturization made the use of thin and thick films virtually imperative. The development of computer technology led to a requirement for very high density storage techniques and it is this which has stimulated most of the research on magnetic properties of thin films. Thin film materials have already been used in semiconductor devices, wireless communication, telecommunications, integrated circuits, rectifiers, transistors, solar cells, LEDs, photoconductors, light crystal displays, magneto-optic memories, audio and video systems, compact discs, electro-optic coatings, memories, multilayer capacitors, flat panel displays, smart windows, computer chips Microelectronics- Electrical conductor, Electrical barriers, diffusion barriers, MEMS, organic electronics, displays, quantum dots Electronic gadgets- CD, DVD, computers, hard drives, GMR, read heads, head lamp reflectors, Semiconductors, Semiconductors chips, transport conducting layers, solar cells, diode advanced solar panels, Sensors- gas sensors, magnetic sensors, magnetic memory, accelometers, as well as other emerging cutting edge technologies, etc.
Micro lithium ion batteries, consisting of thin film electrodes and electrolytes have been of great interest due to their potential applications as power sources for microelectronic devices . As the development of microelectronic devices, the need to develop the micro batteries with high power and high energy density increases. Thin film cathodes of conventional active materials, such as LiCoO 2 , have been reported to use well in thin film batteries [11–13]. However, the thin film cathodes
Thin film diamond electrodes are also used as an inert and chemically and electrochemically stable substrate for the deposition of metal or metal oxide clusters with the aim to utilize the much higher catalytic activity of very small particles (nanoparticles) compared to the conventional bulk material . For some applications these nanoparticles have to be immobilised on a conducting substrate. And this substrate has be not electrochemically active at potentials at which the corresponding electrochemical processes proceed. Because of its unique electrochemical properties in aqueous electrolytes such as the large potential window and low capacitive background currents doped-diamond is especially well suited to serve as such a substrate.
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The present investigation was intended to check the control of polarization by various weak light sources to develop multistate NV-FeRAM logic elements. In this regards, we have characterized two basic configurations of out of plane capacitor-type device. First, we probed a conventional single capacitor (SC) with semi-transparent top Au electrode and conducting LNO bottom electrode. In this particular configuration, the device provides nearly 12% enhancements in polarization under illumination of a weak light source. To improve the effect of light on polarization, we further studied an alternative device structure where two single capacitors situated nearby were connected through bottom electrode in series. It was expected that the second configuration should provide significant enhancement in polarization under illumination of a weak light source since this particular configuration take advantage of the surface polarization as well as out of plane polarization and its maximum interaction with light (surface area). As expected nearly 100% enhancement in polarization was observed for DC configuration for a weak light source. The DC configuration will also provide an extra degree of freedom for miniaturization of an optically active device for future microelectronics.
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