into the solution and color of the solution drastically changes from colorless to yellow, which indicating the formation of silver seed. The solution was left undisturbed at temperature 28 ºC for another 1 hour. After 1 hour, the ITO substrate containing silver seeds was taken out from the seed solution and rinsed with DIW. The remained water on the sample surface was removed by touching the edges of the sample on the tissue paper. After that, the sample was dried in oven at temperature 50 ºC for 1 hour. Before further use in growth process, the sample was placed in petri dish and sealed with parafilm. The schematic of silver seeding process is shown in Fig. 1.
This study focuses on the arrangement of organic thin films by layering with material which well known capable in generating photovoltaic energy. Chlorophyll that doped on the conjugated thiourea (TU) compound will be coated on ITO substrate to increase the ability of light absorption. TU based-compound on D-π-A system should give significance result in the conductivity properties and then act as potential photovoltaic cell molecule. Moreover, TU with its resonance structure has been widely studied with more than 700 structures and its complexes with wide range of transition metals exhibit interesting properties in various applications [18 - 22]. Thus, this study deals with synthesis, characterization and its potential to act as organic photovoltaic cell of the candidate compound namely, N-octyloxyphenyl-N’-(4-chlorobenzoyl)thiourea (3) as shown in Figure 1.
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Here, we measured the resistivity of ITO and FTO substrates after annealing treatment at different tempera- tures (T =20°C, 100°C, 200°C, 300°C, 400°C, and 500°C) for 30 min. The curve is shown in Figure 3. For the ITO substrate, resistivity has a little change while annealing temperature is below 200°C and increases while annealing temperature is more than 300°C obviously. For the FTO substrate, resistivity has little change while annealing temperature is below 500°C. The inset in Figure 3 is the corresponding square resistance. For the ITO substrate, square resistance is 7.96 Ω/□ when annealing temperature is at 20°C and 40.65 Ω/□ at 500°C. It is about five times over. For the FTO substrate, square resistance is 13.48 Ω/□ when annealing temperature is at 20°C and 13.61 Ω/□ at 500°C which are of almost equal values. Because the oxygen holes as conductive carriers in the ITO decrease after 300°C annealing, the resistivity and sheet
grains has been successfully deposited onto ITO substrate at room temperature from non-aqueous bismuth nitrate and sodium thiosulphate solution using a simple, inexpensive, reproducible, and environmentally friendly chemical route method. Film was characterized for structural, surface morphological, optical properties by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectrometer, respectively. In last section, Bi 2 S 3 film on ITO substrate was utilized
substrates from solution containing tungstate ions at three different pH values were observed and recorded by FESEM. Fig. 2a shows SEM image of ITO substrate used in this study in which the morphology appears to have irregularities of small grains and fibril like shape structure with various sizes, ranging from 10 nm to 100 nm. The substrate appears very uniform and highly transparent to the naked eye.
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Vayssieres reported on a method for fabrication of ZnO rods and nanowires in aqueous phase . This route allows for the formation of well-crystallized rod- shaped structures of better uniformity with respect to the samples produced via sol-gel methods [17-19]. Vays- sieres’ original route was based on the thermal decompo- sition of zinc nitrate hexahydrate and methenamine solu- tions. This approach allowed the formation of well- aligned hexagonal ZnO rods, 100 - 200 nm wide and up to 10 µm long [14,20]. However, the study was limited to ZnO rods deposited onto a base film of ITO, without providing further details about the synthesis and charac- terization of the produced materials. Recently, a modi- fication of Vayssieres’ method has been successfully applied by the authors for the preparation of a biosensor for urea . Consequently, the present work is focused on the systematic study of the growth of ZnO NR and its dependence on the type of substrate and the sputtering conditions to deposit the ZnO base layer. The approach is relatively simple and easy-to-scale up and considers the use of a reflux system at 95˚C. Two types of substrate were evaluated: Si(100) and indium tin oxide (ITO), to determine whether their structural features affect the mor- phology of the rods obtained. However, lattice mismat- ches between the ZnO thin film deposited and the sub- strates could have a marked effect on the crystallinity of the rods produced. The mismatch is larger for ZnO base film on Si substrate than for ZnO base film on ITO sub- strate. An estimated lattice-mismatch difference of 40% between Wurtzite ZnO and cubic Si(100) is much harder to cope with than that for zinc oxide on ITO substrate which should exhibit a better crystal quality due to a small estimated lattice-mismatch of about 3% .
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Electrochemical deposition is a low-cost method that can be used to grow high-quality metal, alloy and semiconductor films [15-20]. Many researchers have also tried to use electrodeposition methods to deposit Te-Bi nanowire thermoelectric material on anodic aluminum oxide (AAO) [21, 22]. Li and Miyazaki et al [23, 24] used Au and Pt as the substrate, but the cost of thermoelectric material made with Au and Pt was rather high. In our work we used indium tin oxide (ITO) as the substrate. This material has high light transmission and low resistance and several electrochemical deposition methods were explored for making Bi 2 Te 3 thermoelectric film on ITO substrate.
collection and transport of electrons thereby reducing electron recombination and extending the electron life time in MWCNT composite film . This is because at lower concentrations the MWCNT (upto 0.3 %) enhances the transport of electrons from the films to ITO substrates. At the same time, for the higher concentrations of MWCNT in the composite, it shields the penetration of light source on the anode surface, respectively. Furthermore, Figure. 5a shows the energy level diagram of individual components in the ZnO/MWCNT nanocomposite cells and Figure. 5b explains the efficient electron transport pathway through MWCNT, which enhance the transport of electrons from the film to ITO substrate, respectively.
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Fig.4 shows the top view SEM image of the ZnO film deposited on ITO substrate under the optimal process conditions as above. In the image, it can be seen that the uniform and dense film is constituted of nanorods, which are right hexagonal prisms. These prisms have similar shape and size, and the size is about 1300×130 nm in length and diameter. The slim prisms prove the ZnO nanorods’ growth of c axis (002) preferred orientations. The ZnO film’s XRD pattern is showed in Fig. 3 (80
The cyclic voltammogram was obtained from the electrolyte bath containing the 50 mM ruthenium nitrosyl complexed with ammonia onto ITO substrate at room temperature. Fig. 1 shows the typical CV in the range of 0 to -1.00 V/Ag/AgCl with the scan rate 20 mV/s onto the ITO substrate. From figure the reduction and oxidation peaks are seen in forward and reverse CV scans, respectively. The hydroxide ions in the solution, produced due to the addition of ammonia and nitrate in the solution, are attracted towards cathode at higher potential and RuO 2 .xH 2 O get reduced. Thus the
The substrate was PET sheet, which was degreased ultrasonically in a dilute detergent solution, rinsed in demonized water, and blown dry in N2 gas before they were used.PET substrates were coated by 25 nm of ITO thin film by DC sputtering method. A description of the screen printing process, depicted in Figure 2. The screen is placed a few millimeters above the surface of the PET substrate. Upon loading the silicon pasted solution onto the screen, a rub ‘‘squeegee’’ is then swept with a velocity of several centimeters per second across the surface of the screen, momentarily contacting it to the substrate. At this point, solution flows from the screen to the surface of the PET substrate. As the squeegee then passes over a region, the screen separates from the substrate, leaving behind solution that dries to yield a continuous film. For this study, a screen with area of 40 x40 cm 2 and a mesh count of 181/cm was used.
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Figure 1(a) shows the XRD patterns of the ZnO thin films on the quartz substrates. The 5-nm- thick ZnO film is regarded as an amorphous phase, as shown in Fig. 1(b). With a further increase in the film thickness, intensities of crystalline peaks corresponding to the hexagonal wurtzite phase of ZnO (JCPDS Card No.36-1451) gradually increase, and then, the 20-nm-thick ZnO film is randomly oriented. The size of the nanocrystals was approximately 20 nm, as shown in Fig. 1(c). In the visible region, the transmission of the ZnO films (~ 92%) was almost the same as that of the quartz substrate, regardless of the film thickness. The interface layer located between the transparent conducting electrode and the TiO 2 photoelectrode in the DSSCs needs to be highly transparent in the wavelength
produce the ZnO films on any conductive substrate . The method generates hydroxide ions at the surface of an electrode through the cathodic reduction of the oxygen precursor. The main oxygen source for this reaction is dissolved molecular oxygen or nitrate ions . The structures of the prepared ZnO films can be tailored by controlling the deposition parameters, such as the precursor concentrations, applied voltages, the temperature of the solution and the substrates used [14, 15].
Fluorine-doped tin oxide (SFO) thin films were found to be less reflective and had a lower observed plasma frequency than the ITO thin films studied. The optical properties of these metal oxide thin films determined from reflectance FTIR spectroscopy offer a direct probe, specifically the plasma frequency and reflectivity, to monitor surface events such as adlayer formation (binding of molecules to the surface) or chemical modification of these metal oxide films. These properties could be monitored in situ to yield kinetic information on the binding of molecules to surface bound material or directly to these thin film metal oxide surfaces. The multiplex advantage of FTIR spectroscopy allows the simultaneous determination of the reflectance over a broad spectral range at a fixed or variable angle of incidence instead of monitoring only the reflectance at a single wavelength, while incrementally varying the incident angle typically done with surface plasmon resonance (SPR) protocols using metal surfaces.39 The sensitivity of ITO thin films is such that surface adlayer formation on ITO can easily be observed in the change in reflectivity and the plasma frequency of ITO, while the two different sampling geometries offer flexibility in monitoring the observed plasma frequency and reflectivity of these metal oxide thin films during surface modifications or annealing procedures.
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The materials used in fabricating solar cell consists of ITO glass which act as a substrate on which was Deposited (MEH-PPV) polymer with concentration of 0.2 mg/mL another layer from copper oxide with concentration of 0.3 mg/mL was deposited on the polymer , aluminium was putted on copper oxide to represent the anode while ITO cathode , six cell with different concentrations (0.3,0.29,0.28,0.27,0.26 and 0.25) mg/mL of copper oxide was fabricated by adding certain value of ethanol ,also for doping the polymer was added the chloroform. The devices were characterized by ultra violet visible spectroscopy. Also our apparatus include voltmeter, ammeter, rheostat and light source lamp. Cell was offered to light and the different readings of voltmeter and ammeter were taken by using rheostat.
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Firstly, 3D ITO nanowire networks applied to deep micro V-shaped micro-holes. he Q-switched nanosecond laser (λ = 355 nm, pulse duration: 40 ns, pulse repetition rate: 1 KHz, power: 0.08 W) was used to etch the sample. And then, the PS spheres were coated on the micro-hole arrayed silicon surface by self-assembly. Lastly, the ITO nanowire networks were fabricated by electron beam evaporation for 2000s. he micro-holes and the whole sur- faces were covered by ITO nanowire networks (Fig. 3a). Due to the luidity of the PS in a molten state, it’s possible to carry the grown nanowires to cover the entire micro-hole wall. In order to investigate whether the ITO nanow- ires can extend to the bottom, the hole should be cut-through. Figure 3b shows a cross-section image of the hole with ITO nanowire networks, conirming that the hole has been covered by nanowires completely. he ITO nano- wires could be grown at the bottom of the V-pit with the spacing of only 1 µm (insert image in Fig. 3b). To the best of our knowledge, this is only the method available so far that a conductive ilm can be laid completely under such a deep and small spacing. his network both has good photo-permeability and electrical conductivity. he transmittance of ITO nanowire networks is above 80% in the visible band, according to the sample which were prepared by the same process on a glass substrate (Supplementary Fig. S1). he transmittance of ITO-nanowire ilm is lower than that of ITO ilm, which indicated that ITO nanowires cause light scattering. he sheet resistance is ~150 Ω/sq measured using four-probe method on the surface of micro-hole array Si.
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Typical XRD measurements of ITO films deposited by RF magnetron sputtering at RT are represented in Figure 1a. The low-intensity diffraction peak analogous to an incipi- ent crystallization of the ITO in the (222)-oriented body- centered cubic (bcc) structure has been identified. While other diffraction peaks such as (400), (440), (611), and (622) showing crystallites with other orientation. The re- flection from the (2 2 2) crystalline plane resulted in a characteristic peak at 2 θ = 30.81°, which was close to the peak (2 θ = 30.581°) of the reference ITO [11,16,17]. The structural and morphological characteristics of the ITO film showed polycrystalline ITO growth on Si p-type (100) at RT .
Previously, the powder blasting process has been fre- quently used on ceramic substrate machining. Conventional studies in powder blasting process were carried out with brittle materials such as glass and silicon wafer coated with a protective mask in order to gain desired width. On the other hand, ﬂexible substrate erosion by high-speed particle velocity was also discovered in cold gas dynamic spray coating technology. However, there has been no report on micro patterning of ﬂexible substrate using micro nozzles that were fabricated by semiconductor processing techniques. Micro nozzles, in this study, are fabricated using deep reactive ion etching (DRIE) techniques. Conventionally, micro nozzles have been fabricated using micromachining. As conventional mechanical machining, however, does not guarantee the micron-sized feature size, a number of studies have been conducted to replace conventional mechanical machining. 10,11) Figure 1 shows Scanning Electron Micros- copy (SEM) image of micro nozzle that has been fabricated using DRIE techniques for this study.
Die Diodenkennlinien eines ca. 100 nm dicken, vernetzten „Poly-TPD“-Systems sind für PDBT/PSS-Anoden mit unterschiedlichen Austrittsarbeiten in Abbildung 4.41a dargestellt. Wie man erkennen kann, verschieben sich wie bei dem molekular dotierten PC-System mit 50 Gew.-% TPD (vergl. Abbildung 4.31) die Kennlinien mit zunehmender Austrittsarbeit zu niedrigeren Feldstärken, so dass angenommen werden kann, dass durch die Vernetzung die PDBT/PSS-Schicht nicht zerstört wird und die eingestellte Austrittsarbeit stabil bleibt. Da der Beladungsgrad allerdings vor dem Herstellen der vernetzten TPD-Schicht bestimmt wird, können über die Stabilität der Austrittsarbeit der PDBT/PSS-Filme durch das Vernetzen keine absoluten Aussagen getroffen werden. Im Vergleich zum molekular dotierten System fällt a- ber auf, dass die Diodenkennlinien allesamt zu höheren Feldstärken verschoben sind. Dies gilt sowohl für die PDBT/PSS-Anoden als auch für ITO, wobei die Verschiebung bei konstanter Stromdichte mehr als das Zweifache beträgt. Betrachtet man die Stromdichte bei konstanter Feldstärke, so ergibt sich, dass diese verglichen mit dem molekular dotierten System für die gleiche Elektrode z. T. mehr als eine Größenordnung kleiner ist. Unter der Annahme, dass die resultierende Stromdichte durch den Mechanismus der feldunterstützten thermionischen E- mission beschrieben werden kann, ergeben sich für diese Beobachtung zwei mögliche Ursa- chen (vergl. Gleichung (3.19)).
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in amplitude and phase of polarized light due to their interaction with matter. Measurements with ellipsometer are non contact thereby making it a suitable tool for the investigation of nanostructures. In ellipsometry the changes in the polarization state of light after reflection on a sample or after transmission through a sample can be measured and from these different properties of materials can be established. The ellipsometer is able to measure the amplitude ratio and also the phase difference between the p-polarized and the s-polarized light. The ellipsometer offers the added advantage of obtaining phase information, thereby making it a powerful optical characterization technique  . Different nanostructures such as split ring resonators , fishnet metama- terial   etc. have been characterized using the method of ellipsometry. The method of ellipsometry has also been shown to be very useful in determining the thickness and properties of thin films  . In this work, I employ the method of spectroscopic ellipsometry to optically characterize a fabricated gold nanorod structure. The structure whose unit cell is composed of two gold nanorods of unequal lengths is simulated and the bright and dark resonances for electromagnetic wave incident normally on the structure are obtained. Using the method of ellipsometer we then optically characterized the fabricated gold nanorod on glass substrate. Our experimental results from ellipsometry are found to be in agreement with the results from simulation. Also, aside from the identifying the resonances from the ellipsometric experimental measurements, by using the me- thod of ellipsometry we have obtained the phase information of the fabricated structure.