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VERSATILITY OF THIN FILM AND THIN FILM DEPOSITION TECHNIQUES AND PARAMETERS

VERSATILITY OF THIN FILM AND THIN FILM DEPOSITION TECHNIQUES AND PARAMETERS

ABSTRACT: This article reviews and explores the basic conceptions of an intensive of thin film and deposition techniques. A thin film is a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness. The prime requisite for getting sensible quality thin film is that the optimization of propaedeutic conditions viz. substrate temperature, spray rate, concentration of solution etc. This is often the foremost crucial parameter because it permits management over the scale of the droplets and their distribution over the preheated substrates. The consequences of precursor, dopants, substrate temperature, post tempering treatments, concentration etc., on the physico-chemical properties of those films are given likewise. The properties of the thin film will be simply tailored by adjusting or optimizing these conditions that successively are appropriate for a specific application. The key challenges of spray paralysis are control over the morphology and composition of product particles. It has been widely applied in the past few years.
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Review Paper Thin Film Coating

Review Paper Thin Film Coating

by natural or forced evaporation. A fine adjustment of the evaporation conditions (relative vapour pressure and temperature) and withdrawal speed is necessary to perfectly control the characteristics of the film which includes the thickness of te film and the inner structure. Amid all accessible methods used for this function, dip coating provides the exceptional prospect to precisely direct the vital parameters. In comparison to the other conservative thin film formation processes such as forced or air evaporation, sputtering, chemical vapour deposition (CVD), sol-gel dip coating is potentially economical and requires less equipments. Nevertheless, the most imperative benefit of sol-gel technique over usual thin film coating processes is the capability to mould the micro arrangement of the films to be formed.
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Process Optimization of Deposition Conditions for Low Temperature Thin Film Insulators used in Thin Film Transistors Displays

Process Optimization of Deposition Conditions for Low Temperature Thin Film Insulators used in Thin Film Transistors Displays

Active matrix liquid crystal displays use thin film transistors (TFTs) to address liquid crystal pixels. The first generation TFTs were relying upon hydrogenated amorphous silicon (a-Si:H) as the gate electrode with silicon nitride as the dielectric material [1]. While this was suitable for small displays, for larger ones consisting of huge number of rows and columns, that required high speed addressing circuitry, the structure had to be improved. That is because the high speed addressing schemes normally use CMOS circuits which need high mobility materials to make TFT respond fast enough to these devices [2]. However, The small electron field effect mobility of amorphous material (< 1 cm 2 V -1 s -1 ), was not adequate and as a result, transition
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Application of thin-film technology in Denmark

Application of thin-film technology in Denmark

In recent years there has been a rapid development within the area of thin film photovoltaic modules with respect to increased life time, efficiency and power. However, the market is still dominated by traditional crystalline PV modules, mainly because they have proven their performance and reliability for decades. Thin film PV comes in a variety of materials and visual expressions, and could be an interesting alternative in many applications, in particular BIPV. For this to happen, the lifetime and performance under realistic operating conditions must be well-documented.
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Predictive Calculations of Defects in Thin-Film Heterostructures.

Predictive Calculations of Defects in Thin-Film Heterostructures.

Selecting surfaces of interest is based on input from previous experimental and theoretical studies. Interesting surfaces will typically be those that are often grown or observed, or those for which attempts at growth have been made but are not yet successful. Once the set of surfaces has been decided, the supercells needed for a DFT calculation can be constructed. The goal of the surface calculations in this work are to represent the surface energy of a thin-film material. The thin-films to which these surfaces are being compared are hundreds of nanometers thick, whereas a large supercell in DFT is less than 10nm in one dimension. These calculations must be set up in a way that uses an ultra-thin film to reproduce the behavior of the surfaces of a much thicker film or bulk material. A slab morphology, where the atoms of interest are continuously periodically repeated in two dimensions, but has free surfaces in the other dimension is often used in plane-wave implementations. Due to the periodic nature of plane-wave implementations, the slab supercell is also repeated in the direction above and below the surface. Care must be taken to ensure that the slabs to not interact with their periodic images across the vacuum. Typically this can be accomplished by ensuring that the periodic images are at least 10˚ A away from each other. Polar surfaces, however, provide an additional challenge because depending on how the crystal is terminated, the two surfaces may have different terminations, leading to an electric field in the vacuum. This directional electric field exists across the periodic boundary and leads to calculated energies that change with vacuum distance. This electric field can be avoided if the slab is symmetric along the surface axis and terminated by the same species on each side. This is feasible for {111} surfaces of rocksalt oxides, and indeed this is advantageous because the calculated surface energy will correspond to the creation of two identical surfaces. Note that surface configurations for materials that do not exhibit inversion symmetry (such as the {0001} surfaces of wurtzite GaN or ZnO) require additional considerations that are not discussed here.
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Tetrathiotetracene thin film morphology and electrical properties

Tetrathiotetracene thin film morphology and electrical properties

Large, good quality organic crystals with low impurity/defect concentrations often have higher electrical conductivity than polycrystalline films, but are challenging to grow. It is much easier to produce thin films of organic materials by thermal evaporation in vacuum techniques, but typically such films are polycrystalline. Consequently, it is necessary to investigate the impact of deposition technological parameters on the morphology and electrical properties of such films and TTT was selected for the present study. During (or after) evaporation TTT thin films can be doped with oxidants, such as iodide, dramatically increasing their conductivity. The electrical properties of such doped thin films may therefore depend on the initial TTT thin film morphology. For example, related morphology changes in polycrystalline pentacene films and their effect on electrical properties has been widely studied [10–12]. Some electrical properties of vacuum deposited TTT films have been investigated a long time ago [13–16]. For example, Inokuchi et al. reported TTT electrical resistivity reaching 1.3∙10 6 Ω∙cm for thin films and 8.5∙10 3 Ω∙cm for compressed pellets [13].
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Preparation and Electrochromic Performance of TiO2 Thin Film

Preparation and Electrochromic Performance of TiO2 Thin Film

in the sol, let stand for 15 minutes before make the sol in the glass container flow out at the speed of 3 drops/s. Then keep drying the coated conducting glass in the drying cabinet for 15 minutes, by which the 1-layered film coating work is done. Repeat the above-mentioned steps to prepare the 3-layered film samples. Finally, deal with heat treatment with the coated glass substrate at 150℃ , 200℃ , 250℃ , 300℃ and 400℃ for 2 hours. With the furnace cooling to room temperature, obtain the homogeneous and transparent TiO 2 thin film and make it into 5mm*5mm working electrode for later use.
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Multilayer thin film optical biosensors

Multilayer thin film optical biosensors

The theory described in chapter 4 largely dealt with a near ideal situation, where there is a plane uniform wave incident on a stratified system with smooth, planar boundaries. The real case is, however, very different: the incident light beam is not a plane wave, the thin film thicknesses are not uniform, the boundaries are neither smooth nor planar and the materials may scatter the incident light. Additionally, there is the binding o f the analyte, capture antibody and labelled antibody to consider because this clearly affects how much o f the fluorescent label is brought within the strong evanescent field close to the waveguide layer. This chapter extends the theory o f chapter 4 to include thin film thickness non-uniformities and the presence o f a bound protein layer and applies this to the immunosensor measurements presented in chapter 7. The modelling presented is neither mathematically complex nor comprehensive, but the results provide some insight into the various sources (eg. scattering from the thin film layers, fluorescence, etc.) that combine to produce the observed signal.
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THIN FILM DEPOSITION BY SPRAY PYROLYSIS TECHNIQUES

THIN FILM DEPOSITION BY SPRAY PYROLYSIS TECHNIQUES

A Chemical spray paralysis (CSP) is used for depositing a wide variety of thin films, which are used in devices like solar cells, sensors, solid oxide fuel cells etc. It has evolved into an important thin film deposition technique and is classified under chemical methods of deposition. This method offers a number of advantages over other deposition processes, the main ones being scalability of the process, cost- effectiveness with regard to equipment costs and energy needs, easiness of doping, operation at moderate temperatures (100-500˚C) which opens the possibility of wide variety of substrates, control of thickness, variation of film composition along the thickness and possibility of multilayer deposition. CSP technique involves spraying a solution, usually aqueous, containing soluble salts of the constituents of the desired compound onto a heated substrate. Typical CSP equipment consists of an atomizer, a substrate heater, temperature controller and a solution container. Additional features like solution flow rate control, improvement of atomization by electrostatic spray or ultrasonic nebulization can be incorporated into this basic system to improve the quality of the films. To achieve uniform large area deposition, moving arrangements are used where either nozzle or substrate or both are moved. There are too many processes that occur sequentially or simultaneously during the film formation by CSP. These include atomization of precursor solution, droplet transport, evaporation, spreading on the substrate, drying and decomposition. Understanding these processes will help to improve film quality. Deposition process in CSP has three main steps: atomization of precursor solutions, transportation of the resultant aerosol and decomposition of the precursor on the substrate.
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Planar Defects in Metallic Thin Film Heterostructures.

Planar Defects in Metallic Thin Film Heterostructures.

However, there have been no experimental reports regarding the grain size effect on the formation of twins during the synthesis of NC metal films. In this paper, we have investigated the grain size effect on twin density in NC copper films synthesized by pulsed laser deposition, where grain size ranged from ~2 nm to ~10 nm. The characteristics and number density of twins were studied as a function of grain size, using transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The internal strain inside the NC Cu thin film was calculated from X-ray θ - 2θ scan diffraction pattern using the Williamson and Hall analysis [21]. Our analysis indicates that the observed twin density dependence on grain size is consistent with deformation twins instead of pure growth twins. The rationale for this phenomenon is discussed in terms of internal strains present in as- deposited films.
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Studies in shallow and thin-film flows

Studies in shallow and thin-film flows

direction is much smaller than the characteristic length scale (L) in the stream wise direction. The flow takes place predominantly in the direction of the longer dimension. Thin-film or shallow flow are the same type of flows and they represent similar flow characteristics. In the present study we have mainly dealt with shallow flow. The influence of inertia, surface tension are examined in this study as from the existing literature (O’Brien & Schwartz 2002, Myers 1998, O’Brien & Van Den Brule 1989), it is found that surface tension is important in small scale and thin-film flow and for capillary waves. Surface tension is also important in porous media and oil medium due to the small capillary number values (http://en.wikipedia.org/wiki/Capillary_number) in these mediums. Several studies (O’Brien & Schwartz 2002, Myers 1998, O’Brien & Van Den Brule 1989) have demonstrated that surface tension is important in thin-film and shallow flow and it cannot be neglected in thin-film and shallow flow. Now we will concentrate our study on shallow flow to determine the bottom stress in a shallow tailings pond.
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Pulsed Laser Deposition of Thin Film Heterostructures

Pulsed Laser Deposition of Thin Film Heterostructures

operating at 266nm, with a pulse widths between 14-15ns, at a repetition rate of 10 hertz (Hz) was used for PLD; these parameter were used for all the TD thin films produced, the only adjusted parameter was the fluence. As mentioned before in chapter 4 section 3, as a result of working parameters and the focusing lens the projected laser spot on the target was a line. To change this to a more desired circular laser spot a new focusing lens was used to produce the TD thin films, note that the only TD thin film produced using the old focusing lens configuration was TD250/PTO275 as a result the deposition rate was lower than the other films of comparable thickness. The previous lens was replaced by a fused silica plano-convex lens made by CVI Melles Griot and the procedure to determine the laser fluence was the same as described in chapter 4 section 3.
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Existence of Solutions to a Viscous Thin Film Equation

Existence of Solutions to a Viscous Thin Film Equation

can be taken as a thin film equation or a Cahn-Hilliard equation with a dege- nerate mobility. The entropy functional method is introduced to overcome the difficulties that arise from the degenerate mobility m u ( ) and the viscos- ity term. The existence of nonnegative weak solution is obtained.

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Effects of Radiation on Ferroelectric Thin Film Materials.

Effects of Radiation on Ferroelectric Thin Film Materials.

As mentioned previously, EBSD is usually performed on bulk materials due to the high penetration volume. In order to understand the strain distribution in thin film samples by analyzing the shifts of Kikuchi bands relative to a reference pattern, TKD is applied instead. In the strain analysis of this work, the real reference method was used. In order to collect high quality patterns, an exposure time of 164 ms with 4 frames was used (a total of 656 ms) at each scan point. A 1 ×1 binning mode coupling with low gain mode was used to ensure the maximum resolution of the patterns. The best Kikuchi patterns were achieved using a 30 kV voltage and 16 nA current with a scan step size of ~13 nm. Cubic PZT was used to index the acquired patterns. OpenXY was used to calculate the relative strain distribution in undoped and Mn-doped PZT films. The phase information of cubic PZT and the experiment setup parameters used in OpenXY are summarized in Table 4-1. For each grain, a reference pattern was chosen at the point where the pattern quality is the maximum. The change of the pattern quality can be related to the elastic strain gradient. 39 Previous research reported that a minimum
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Ruthenium Oxide: Thin Film and Electrochemical Properties

Ruthenium Oxide: Thin Film and Electrochemical Properties

in 0.1 M KOH electrolyte. Figure7. shows the C-V of ruthenium oxide thin film electrodes annealed at 900°C temperature. The capacitive behaviour of the oxide is enhanced by rectangular shape of the plot. [21] The electrode potential scanned between -600 mV to 800 mV in both anodic and cathodic directions for a thin film electrode annealed at 900°C showed the typical pseudocapacitive behaviour.

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Thin Film Composite and/or Thin Film Nanocomposite Hollow Fiber Membrane for Water Treatment, Pervaporation and Gas/Vapor Separation

Thin Film Composite and/or Thin Film Nanocomposite Hollow Fiber Membrane for Water Treatment, Pervaporation and Gas/Vapor Separation

Sukitpaneenit and Chung [42] fabricated novel membranes with a thin selective polyamide layer, which was formed by interfacial polymerization onto a porous polyethersulfone (PES) hollow fiber support (free of macrovoids). The PES support was fabricated via dual-layer co-extrusion technology. A thin film of polyamide layer on the inner surface of PES hollow fiber was formed by an interfacial polymerization (IP) between the MPD monomer in the aqueous phase and the TMC monomer in the organic phase. The surface of the TFC was modified by coating with either polydopamine or silicone rubber. The polydopamine or silicone rubber coated membranes exhibited water separation factors of up to 51 and 60, with substantial high fluxes of 6.6 and 7.5 kg m −2 h −1 , respectively, when used in pervaporation
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Thin Film Shape Sensing: The Development of an Integrated Flexible Thin Film Temperature-Compensated Strain Sensing Array

Thin Film Shape Sensing: The Development of an Integrated Flexible Thin Film Temperature-Compensated Strain Sensing Array

RT, and 9-13 Ohms at 113°C. Included in the table is the TCR as-measured. Note that Pt sensors have very small scatter in resistance and TCR values, and TCR values are an order of magnitude higher for Pt than for NiCr, as expected. The Pt TCR values of ~0.0024 /°C are lower than that of bulk Pt (0.00385), presumably due to the thin-film microstructure and effects of impurities. Some scatter in the NiCr resistance and TCR values is observed, revealing the sensitivity of NiCr to impurities during deposition, and air exposure. The TCR of NiCr is known to be a function of Ni/Cr ratio, and amount of Oxygen impurity. High-temperature post-process anneals are known to stabilize NiCr against atmospheric reaction. Nevertheless, the effect of choosing sensor pairs materials of varying properties is demonstrated.
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Orthogonal Thin Film Photovoltaics on Vertical Nanostructures

Orthogonal Thin Film Photovoltaics on Vertical Nanostructures

Decoupling paths of carrier collection and illumination within photovoltaic devices is one promising approach for improving their efficiency by simultaneously increasing light absorption and carrier collection efficiency. Orthogonal photovoltaic devices are core-shell type structures consisting of thin film photovoltaic stack on vertical nanopillar scaffolds. These types of devices allow charge collection to take place in the radial direction, perpendicular to the path of light in the vertical direction. This approach addresses the inherently high recombination rate of disordered thin films, by allowing semiconductor films with minimal thicknesses to be used in photovoltaic devices, without performance degradation associated with incomplete light absorption. This work considers effects which influence the performance of orthogonal photovoltaic devices. Illumination non-uniformity as light travels across the depth of the pillars, electric field enhancement due to the nanoscale size and shape of the pillars, and series resistance due to the additional surface structure created through the use of pillars are considered. All of these effects influence the operation of orthogonal solar cells and should be considered in the design of vertically nanostructured orthogonal photovoltaics.
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Thin Film Solar Charge Controller: A Research Paper for Commercialization of Thin Film Solar Cell

Thin Film Solar Charge Controller: A Research Paper for Commercialization of Thin Film Solar Cell

Thin-film solar cell manufacturers begin building their solar cells by depositing several layers of a light-absorbing material, a semiconductor onto a substrate -- coated glass, metal or plastic. The materials used as semiconductors don't have to be thick because they absorb energy from the sun very efficiently. As a result, thin-film solar cells are lightweight, durable and easy to use. There are three main types of thin-film solar cells, depending on the type of semiconductor used: amorphous silicon (a-Si), cadmium telluride (CdTe) and copper indium gallium desalinide (CIGS). Amorphous silicon is basically a trimmed-down version of the traditional silicon-wafer cell. As such, a-Si is well understood and is commonly used in solar-powered electronics. It does, however, have some drawbacks.
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EFFECT OF INTERMOLECULAR FORCES ON THIN FILM INSTABILITY

EFFECT OF INTERMOLECULAR FORCES ON THIN FILM INSTABILITY

Abstract: We consider the effect of van der Waals intermolecular forces on instability problems occurring in thin liquid film pattern formation induced by an electric field. The physical setup is a layer of thin liquid film sandwiched between two electrodes and separated by an air gap from the top mask electrode. We formulate the nonlinear parabolic fourth order thin film equation by deriving van der Waals forces, electric induced forces and incorporate the surface tension in the model. In the long wavelength limit, we find that perturbations at the interface undergo regulated dynamics and the initial film thickness plays a critical role in the pattern formation process.
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