共查询到20条相似文献,搜索用时 15 毫秒
1.
M. Abraham 《Thin solid films》1983,109(2):93-102
A method is developed for determining the refractive index of transparent films of medium thickness over a spectral region in which the dispersion cannot be neglected. The advantage of the method is that it does not require any information about the thickness or the interference order. The method is tested numerically and applied to a CdS film in the region below the fundamental absorption. 相似文献
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A contactless method based on the laser-beam-induced thermocapillary effect is proposed for measuring the thickness of a thin liquid film on a flat solid surface. The method can be also used to measure the films with inhomogeneous thicknesses formed on a nonhorizontal substrate. 相似文献
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The optical constants of thin films can be obtained from inversion of spectrophotometric measurements by using minimization gradient methods. The computational approach of these minimization methods requires closed compact formulas for reflectance and/or transmittance. For normal incidence closed compact formulations for the direct transmittance, both for thin films on transparent or absorbing substrates, and for the reflectance of thin films on transparent substrates, are available in the literature. We report here a closed compact formula to evaluate reflectance spectra of thin films on absorbing substrates, and it is shown that for vanishing substrate absorption this new, to the best of our knowledge, approach gives the same results obtained from the formulation corresponding to thin films supported by transparent substrates. 相似文献
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F. Ruffino I. Crupi E. Carria S. Kimiagar F. Simone M.G. Grimaldi 《Materials Science and Engineering: B》2013,178(9):533-541
Fabrication processes of Au nanostructures on indium-tin-oxide (ITO) surface by simple, versatile, and low-cost bottom-up methodologies are investigated in this work. A first methodology exploits the patterning effects induced by nanosecond laser irradiations on thin Au films deposited on ITO surface. We show that after the laser irradiations, the Au film break-up into nanoclusters whose mean size and surface density are tunable by the laser fluence. A second methodology exploits, instead, the patterning effects of standard furnace thermal processes on the Au film deposited on the ITO. We observe, in this case, a peculiar shape evolution from pre-formed nanoclusters during the Au deposition stage on the ITO, to holed nanostructures (i.e. nanorings), during the furnace annealing processes. The nanorings depth, height, width, and surface density are shown to be tunable by annealing temperature and time. 相似文献
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A new calculating method to deduce optical constants n, k and thickness d from the fringe pattern of the transmission spectrum is proposed. In this method the optical parameters are determined using only one curve of the transmission spectra even for thin films where nd < /4. The method is demonstrated by experimental data obtained using evaporated vacuum deposited TiO2 thin film on a glass substrate. The experimental values are in very good agreement with those calculated using the above described technique. 相似文献
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Hwang JC Choi MC Ha Y Kim CW Kim Y Kim I Ha CS 《Journal of nanoscience and nanotechnology》2011,11(1):550-554
The imide-functionalized polynorbornene films exhibited excellent optical transparency in the visible range as well as high thermal stability over 200 degrees C. The indium tin oxide (ITO) thin films were coated on the imide-functionalized polynorbornene films at various deposition temperatures by employing radio-frequency (r.f.) planar magnetron sputtering system. The resulting ITO-coated imide-functionalized polynorbornene substrates showed good electrical and optical properties, while the figure of merit examination revealed that the present substrates are comparable to conventional ITO-glass substrates. This was confirmed from the preliminary result of organic light-emitting devices fabricated using the imide-functionalized polynorbornene substrates. 相似文献
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Fumiaki Mitsugi Aya Matsuoka Yoshihiro Umeda Tomoaki Ikegami 《Thin solid films》2010,518(22):6330-6333
The gallium doped zinc oxide has been one of the candidates for the transparent conducting oxide thin film electrode. It is not suitable to use a conventional light interference method to measure the thickness of the gallium doped zinc oxide thin film because the refractive index and extinction coefficient of the thin film is unknown during the optimization of the deposition conditions. In this paper, we report on the details of the film thickness program which uses the measured optical and electric properties and relationship between the plasma frequency and the optical constant of the film. The obtained film thickness of the prepared gallium doped zinc oxide thin film using the program was comparable with thicknesses measured by a cross-sectional analysis of the atomic force microscopy and the surface profiler. Moreover, the optical constant of refractive index and extinction coefficient of the film could also be estimated. 相似文献
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A method for determining the optical properties of a film on an isotropic substrate is proposed. The method is based on the existence of two specific incidence angles in the angular interference pattern of the p-polarized light where oscillations of the reflection coefficient cease. The first of these angles, theta(B1), is the well-known Abelès angle, i.e., the ambient-film Brewster angle, and the second angle theta(B2) is the film-substrate Brewster angle. In the conventional planar geometry and in a vacuum ambient there is a rigorous constraint epsilon(1) + epsilon > epsilon(1)epsilon on the film and the substrate dielectric permittivities epsilon(1) and epsilon, respectively, for the existence of the second angle theta(B2.) The limitation may be removed in an experiment by use of a cylindrical lens as an ambient with epsilon(0) > 1, so that both angles become observable. This, contrary to general belief, allows one to adopt the conventional Abelès method not only for films with epsilon(1) close to the substrate's value epsilon but also for any value of epsilon(1). The method, when applied to a wedge-shaped film or to any film of unknown variable thickness, permits one to determine (i) the refractive index of a film on an unknown substrate, (ii) the vertical and the horizontal optical anisotropies of a film on an isotropic substrate, (iii) the weak absorption of a moderately thick film on a transparent or an absorbing isotropic substrate. 相似文献
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Ramesh M. KrishnaTimothy C. Hayes Daniel KrementzGeorge Weeks Adrián Méndez TorresKyle Brinkman Krishna C. Mandal 《Materials Letters》2012,66(1):233-235
In this work, we investigate the optical and electrical properties of various transparent conductive oxide (TCO) thin films deposited on insulating ceramics for emerging optoelectronic applications. Thin films investigated include indium tin oxide (ITO), ruthenium oxide (RuO2), and iridium oxide (IrO2) on Al2O3 ceramic substrates. The conducting films have been deposited by various techniques including RF magnetron sputtering and low-cost spray pyrolysis. The morphological characteristics of the films were carried out using high magnification optical microscopy and atomic force microscopy (AFM). Optical and electrical characterization was carried out by optical absorbance/transmittance, van der Pauw, current-voltage (I-V), and Hall effect measurements. The results are presented in this paper. 相似文献
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The quality of polydihydrosilane liquid films is a key factor in the fabrication of solution-processed silicon films. This study investigates the stability of polydihydrosilane liquid films with a thickness L of ~ 40 nm on solid substrates by a comparison between the observed optical microscope images and the values of the Hamaker constant AALS for the air/liquid (polydihydrosilane)/solid substrate systems. AALS values for a series of SiO2-based substrates were determined by adopting a simple spectrum method. We found that the micrographs of the polydihydrosilane films provide direct evidence of stability in accordance with the sign of AALS; a stable liquid film with AALS > 0 showed a continuous figure, while an unstable film with AALS < 0 exhibited an array of dots caused by the rupture of the film. The array of dots in the unstable liquid films has a slight orderly distribution with a period λ that is in accord with the characteristic wavelength of the undulation related to the spinodal-like decomposition in van der Waals unstable liquid. 相似文献
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J.J. Vlassak 《International Journal of Fracture》2003,119(4):299-323
Solutions are presented for the elastic plane-strain problem of a crack in a coating on a compliant substrate of finite thickness. Analysis of the problem shows that substrate thickness has a significant effect on the steady-state energy release rate for channel cracks. This is so over a wide range of elastic mismatch between film and substrate, but is especially important if the substrate is more compliant than the film. Relaxation of the film stress due to elastic deformation of the substrate also plays an important role. If the substrate is clamped around the edge, as would be the case for a coated membrane, the stress in the coating cannot relax and the energy release rate for channel cracking increases significantly with decreasing substrate thickness. If the film stress is allowed to relax, however, the driving force for cracking is reduced as the substrate thickness decreases. The results from this study are used to evaluate the change in curvature of a film/substrate assembly due to channel cracking, a quantity that is of interest for the experimental determination of stresses in thin films. An expression for the elastic extension of the substrate due to channel cracking is derived making it possible to evaluate the effect of cracking on the mechanical behavior of bilayer membranes. It is expected that the present study may lead to the development of new experimental techniques for measuring the fracture toughness of thin coatings. 相似文献
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Marangoni convection plays an important role in hydrodynamics of evaporating liquid films and sessile drops. Evaporation of
liquid films induces unsteady nonuniform temperature distribution across the liquid layer and in a substrate. If the substrate
is composed of parts with different thermal properties, the interface temperature distribution becomes non-uniform, leading
to appearance of Marangoni stresses, convective vortices, and film deformation. In this article, a model describing evaporation,
Marangoni effect and interface dynamics of liquid films on composite substrates is developed. The film dynamics is described
in the framework of long-wave theory. The unsteady heat conduction in the substrate is described using the Laplace transform
method for semi-infinite substrates and using the separation of variables technique for substrates of finite thickness. The
non-uniformity of substrate thermal properties has a pronounced effect on film dynamics. 相似文献
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Optically transparent and electrically conductive single-walled carbon nanotube (SWNT) thin films were fabricated at room temperature using a dip-coating technique. The film transparency and sheet resistance can be easily tailored by controlling the number of coatings. Aminopropyltriethoxysilane (APTS) was used as an adhesion promoter and, together with surfactant Triton X-100, greatly improved the SWNTs coating. Only five coats were required to obtain a sheet resistance of 2.05?[Formula: see text] and film transparency of 84?%T. The dip-coated film after post-deposition treatment with nitric acid has a sheet resistance as low as 130?[Formula: see text] at 69?%T. This technique is suitable for large-scale SWNT coating at room temperature and can be used on different types of substrates such as glass and plastics. This paper will discuss the role of the adhesion promoter and surfactant in the coating process. 相似文献
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The influence of the initial resistivity on the life stability of thin In2O3-SnO2 films deposited onto cold substrates was investigated. We tried to improve the life stability with protective layers. A method of producing thin films with low initial resistivities is presented and the influence of the substrate on the initial resistivity is described. 相似文献