Showing papers on "Thin film published in 1983"
TL;DR: In this article, a free-energy diagram is used to explain the single-phase amorphous product of pure polycrystalline Au and La thin films at temperatures of 50-80°C.
Abstract: Single-phase Au1-xLax alloys, with 0.3≲x≲0.5, have been formed through solid-state interdiffusion of pure polycrystalline Au and La thin films (100-600 A) at temperatures of 50-80°C. The reaction is driven by the large negative heat of mixing in the amorphous alloy and occurs at low temperatures by the anomalously fast diffusion of Au in La. The composition regime giving a single-phase amorphous product is explained with use of a free-energy diagram.
1,009 citations
Book•
01 Jan 1983
TL;DR: In this paper, the authors present fundamental physical principles rather than the state-of-the-art for solar cell research and illustrate basic phenomena and to indicate possibilities for innovative design, including concentrators, concentrator systems, and photoelectrochemical cells.
Abstract: This text is addressed to upper level graduate students with background in solid state physics and to scientists and engineers involved in solar cell research. The author aims to present fundamental physical principles rather than the state-of-the-art. Specific devices are used to illustrate basic phenomena and to indicate possibilities for innovative design. Contents, abridged: Solar insolation. The calculation of solar efficiency. Silicon solar cells. Heterojunction and heteroface structure cells. Polycrystalline thin films for solar cells. Concentrators, concentrator systems, and photoelectrochemical cells.
780 citations
Book•
31 Jul 1983
TL;DR: In this paper, the basic physical processes in solar cell materials are discussed, and the properties of thin films for solar cells are discussed. And the authors propose a novel concept in the design of high efficiency solar cells.
Abstract: Why Thin Film Solar Cells?- Basic Physical Processes in Solar Cell Materials- Photovoltaic Behavior of Junctions- Photovoltaic Measurements, Junction Analysis, and Material Characterization- Thin Film Deposition Techniques- Properties of Thin Films for Solar Cells- Cu2S Based Solar Cells- Polycrystalline Thin Film Silicon Solar Cells- Emerging Solar Cells- Amorphous Silicon Solar Cells- Photoelectrochemical Cells- Novel Concepts in Design of High-Efficiency Solar Cells
674 citations
TL;DR: Amorphous hydrogenated carbon thin films (a-C:H) were prepared by r.f. plasma deposition from benzene vapor and optical absorption in the range 0.2-25.0 μm was measured and used for bonding analysis as discussed by the authors.
604 citations
TL;DR: In this article, the authors describe the deposition of amorphous hydrogenated hard carbon (a-C:H) thin films from benzene vapor in a rf plasma.
Abstract: The deposition of amorphous hydrogenated hard carbon (a–C:H) thin films from benzene vapor in a rf plasma is described. a–C:H was deposited on glass, quartz, Si, Ge, and GaAs. Negative self‐bias VB and gas pressure P are shown to be the two significant parameters for an accurate control of the deposition process. The dependence of growth rate and deposition temperature on VB and P was determined; this gives an empirical relation for the average energy E of the ions forming the thin films. Refractive index (1.85–2.20 in the IR), optical gap (0.8–1.8 eV) and density (1.5–1.8 g/cm3) of a–C:H was measured. The optical gap varies linearly with the content of bonded hydrogen in the films. The density of a–C:H is proportional to the average ion energy E. We demonstrate the application of a–C:H as antireflective coating on Ge for 10.6 μm (reflection <0.2% at 10.6 μm) and as terminating layer of an optical multilayer stack.
471 citations
TL;DR: In this paper, a property-structure correlation between monomers and their corresponding polymers is obtained by systematic variation of the chemical structure of the monomers, with conductivity of the order of 1 ohm/sup-1/ cm/sup -1/
Abstract: Polythiophene and ..beta..-substituted polythiophenes are prepared by electrochemical oxidation and polymerization of their respective monomers. A property-structure correlation between monomers and their corresponding polymers is obtained by systematic variation of the chemical structure of the monomers. Film growth and conductivities are dependent on ..beta..-substituents, with conductivity of the order of 1 ohm/sup -1/ cm/sup -1/ obtained for poly(..beta..-methylthiophene).
437 citations
375 citations
TL;DR: In this paper, the direct etching of polyethylene terephthalate (PET) film using a XeCl laser has been investigated and is shown to be consistent with a thermal model for degradation.
Abstract: The direct etching of polyethylene terephthalate film using a XeCl laser has been investigated and is shown to be consistent with a thermal model for degradation. Microstructure revealed by deep etching suggests the UV laser may prove useful for studying polymeric materials. Polyimide and photoresist film has also been directly etched.
355 citations
TL;DR: Substantial increases in the packing densities of SiO2, TiO2 , and ZrO2 films have been produced as measured by the reduction in the adsorption of moisture when the films are exposed to a humid atmosphere.
Abstract: Some effects on the properties of electron-beam evaporated thin films produced by ion bombardment of the growing film are reported. Substantial increases in the packing densities of SiO2 , TiO2 , and ZrO2 films have been produced as measured by the reduction in the adsorption of moisture when the films are exposed to a humid atmosphere. In a ZrO2-SiO2 multilayer interference filter, changes in the wavelength of the peak transmittance on exposure to the atmosphere have been reduced from 8 nm for films deposited without ion bombardment to <1 nm for ion-beam-assisted films.
316 citations
TL;DR: In this paper, the magnetron sputtering technique was used to produce highly transparent (transmission ∼90%) and conducting (resistivity ∼10−5 Ω'cm) indium tin oxide (ITO) films.
Abstract: Indium tin oxide (ITO) films have been prepared by the magnetron sputtering technique from a target of a mixture of In2O3 and SnO2 in the proportion 9:1 by weight. By optimizing the deposition conditions it has been possible to produce highly transparent (transmission ∼90%) and conducting (resistivity ∼10−5 Ω cm) ITO films. A resistivity ∼10−4 Ω cm has been obtained for films of thickness ∼1000 A at a comparatively low substrate temperature of 50 °C and without using oxygen in the sputtering chamber. To characterize the films, the following properties have been studied, viz., electrical conductivity, thermoelectric power, Hall effect, optical transmission, and band gap. The effect of annealing in air and vacuum on the properties of the films have also been studied.
304 citations
TL;DR: In this paper, the acceleration effect of ions with moderate energies (10 to 20 eV), using a microwave ECR (Electron Cyclotron Resonance) excited plasma, and a plasma stream extraction onto the specimen table by a divergent magnetic field method.
Abstract: The plasma deposition apparatus developed in this study can realize a deposition of dense and high quality thin films, such as Si3N4 and SiO2, without the need for substrate heating. It does this by enhancing the plasma excitation efficiency at low gas pressures (10-4 Torr) and by the acceleration effect of ions with moderate energies (10 to 20 eV), using a microwave ECR (Electron Cyclotron Resonance) excited plasma, and a plasma stream extraction onto the specimen table by a divergent magnetic field method. The Si3N4 and SiO2 films deposited are comparable to those prepared by high temperature CVD and thermal oxidation, respectively, in evaluations such as by buffered HF solution etch rate measurement.
TL;DR: In this article, a model for the epitaxial growth of by the organometallic process is proposed, based on these findings, and the growth rate is studied as a function of the growth parameters and substrate orientation, and is related to the decomposition of the two reactants trimethylgallium and arsine.
Abstract: Epitaxial layers of have been grown in an atmospheric organometallic CVD system, for a wide variety of gas phase reactant partial pressures and over a broad range of temperature (450°–1050°C). The growth rates for (100), , (110), (11l)Ga, and (11l)As substrates are reported as functions of temperature and gas composition. Three distinct temperature dependent regions of growth are identified, corresponding to a mid‐temperature mass transport limited range, a low‐temperature kinetic controlled regime, and a high‐temperature desorption limited region. The growth rate is studied as a function of the growth parameters and substrate orientation, and is related to the decomposition of the two reactants trimethylgallium and arsine. A model for the epitaxial growth of by the organometallic process is proposed, based on these findings.
TL;DR: In this paper, the properties of carbide and nitride films were characterized by scanning electron microscopy and X-ray diffraction and through measurements of the microhardness and electrical resistivity.
TL;DR: In this paper, a high resolution x-ray diffractometer is described in which a compact four-crystal monochromator produces a highly parallel and non-convex incident beam of tuneable wavelength (divergence Δθ=5″, wavelength band Δλ/λ=2.3×10−5, intensity 3×104 photons/s
Abstract: A high resolution x‐ray diffractometer is described in which a compact four‐crystal monochromator produces a highly parallel and monochromatic incident beam of tuneable wavelength (divergence Δθ=5″, wavelength band Δλ/λ=2.3×10−5, intensity 3×104 photons/s mm2). The instrument is very suitable for the nondestructive measurement of concentration depth profiles produced in semiconductor single crystals by epitaxy, diffusion, or implantation. The equipment is useful for measuring x‐ray rocking curves of any lattice plane of any material and also lattice constants can be determined on absolute scale using the Bond procedure. A special solution has been derived from the dynamical theory of x‐ray diffraction, which gives the reflectivity of an absorbing layer as a function of layer thickness. This new expression takes the effects of absorption and extinction into account and has been used to determine the layer thickness of epitaxial layers grown on [001] oriented InP.
TL;DR: A new technique has been developed that employs highly focused laser beams for both generating and detecting thermal waves in the megahertz frequency regime and includes a comprehensive 3-D depth-profiling theoretical model; it has been used to measure the thickness of both transparent and opaque thin films with high spatial resolution.
Abstract: A new technique has been developed that employs highly focused laser beams for both generating and detecting thermal waves in the megahertz frequency regime. This technique includes a comprehensive 3-D depth-profiling theoretical model; it has been used to measure the thickness of both transparent and opaque thin films with high spatial resolution. Thickness sensitivities of ±2% over the 500–25,000-A range have been obtained for Al and SiO2 films on Si substrates.
TL;DR: In this paper, the authors discuss important factors to achieve high quality MBE growth such as in situ analysis, substrate preparations, growth conditions and layer properties, as well as their application in solid state devices.
TL;DR: The first application of optical enhancement to thin-film (∼0.75 μm) amorphous silicon solar cells was described in this paper, where the authors defined cell geometries which maximize enhancement effects.
Abstract: We describe the first application of optical enhancement to thin‐film (∼0.75 μm thick) amorphous silicon solar cells and define cell geometries which maximize enhancement effects. We observed that due to the improved infrared absorption the external AM1 short circuit current increases by 3.0 mA/cm2 in cells constructed in accordance with the principles of optical enhancement.
TL;DR: Ferroelectric films of lead zirconate titanate (PZT) have been fabricated by rf planar magnetron sputtering as mentioned in this paper, and the sputtering rate is in the range 0.2-1.0 μm/h and varies with sputtering pressure and substrate temperature.
Abstract: Ferroelectric films of lead zirconate titanate (PZT) have been fabricated by rf planar magnetron sputtering. Films having a resistivity >106 Ω cm and a dielectric constant >800 at 300 K have been achieved using 100% oxygen as a sputtering medium, 10% excess PbO added to the target, and appropriate post‐deposition annealing. The sputtering rate is in the range 0.2–1.0 μm/h and varies with sputtering pressure and substrate temperature. Post‐deposition annealing affects both crystallinity and grain size, but incipient crystallization formed only in as‐grown films deposited at substrate temperatures >400 °C is essential for this process to be effective. A clear ferroelectric transition is observed at 350 °C, while the activation energy for dc conductivity of around 0.8 eV is consistent with bulk properties of PZT. The spontaneous polarization and coercive field measured from ferroelectric hysteresis loops is 20.75 μC/cm2 and 10 kV/cm, respectively. The optical transmittance of the films is determined by a Pb–Pb charge transfer band near 400 nm and this is a sensitive test of film stoichiometry.
TL;DR: A Monte-Carlo simulation technique based on the screened Rutherford differential cross section for the elastic scattering and Gryzinski's semi-empirical expression for the inelastic core and valence electron excitation is used to describe electrons and positrons slowing down in solids as discussed by the authors.
Abstract: A Monte-Carlo simulation technique based on the screened Rutherford differential cross section for the elastic scattering and Gryzinski's semiempirical expression for the inelastic core and valence electron excitation is used to describe electrons and positrons slowing down in solids. The theoretical results are compared with the experimental backscattering, absorption and transmission results for aluminum, silicon, copper, and gold thin film and semi-infinite targets and good agreement is observed. The simulated stopping profiles are fitted with a simple analytic expression. The profiles are Laplace-transformed to give a useful data base for analyzing phenomena associated with slow positron re-emission from solids.
TL;DR: In this article, a model of a thin-film solar cell is presented that can be easily used to analyze solar cell properties and the continuity equations are solved using the regional approximation, producing elementary solutions that give insight into the physics of the transport in the cell.
Abstract: A model of a p‐i‐n thin‐film solar cell is presented that can be easily used to analyze solar cell properties. The continuity equations are solved using the regional approximation, producing elementary solutions that give insight into the physics of the transport in the cell. The steady‐state solutions are compared with measurements on typical hydrogenated amorphous silicon, a‐Si:H, solar cells. The ac solutions are used to explain a new source of photocapacitance due to mobile carriers.
TL;DR: In this paper, a method for the electrodeposition of thin films of cupric hexacyanoferrate on glassy carbon and tin oxide electrodes has been devised, which is consistent with a model previously reported for Prussian blue films.
Abstract: A method for the electrodeposition of thin films of cupric hexacyanoferrate on glassy carbon and tin oxide electrodes has been devised. At low scan rates, in , these films exhibit nearly ideal cyclic voltammetric current‐potential waves with a peak potential of +0.69V vs. SCE on glassy carbon. Similar to the Prussian blue films described by Neff (1, 2), Itaya (3), and others (4), potassium ion is transported into the film during reduction. XPS and visible spectroscopy indicate that the redox involves the ferric and ferrous states of the hexacyanoferrate and not . The electrochemical properties as a function of potassium ion concentration and film thickness have been determined primarily from cyclic voltammetric studies, and evidence for electronic conduction through the film has been observed. Optical properties of the films were determined using deposited on tin oxide substrates. Supporting description of the electrochemical properties of the film has been obtained by a‐c impedance measurements. The film behavior is consistent with a model previously reported for Prussian blue films.
TL;DR: In this article, the general principle of wavelength-selective enhancement of absorption in thin-film solar cells by a periodic grating substrate was presented, and substantial short-circuit current gains were realizable in thinfilm amorphous silicon (a•SiHx) solar cells.
Abstract: We present the general principle of wavelength‐selective enhancement of absorption in thin‐film solar cells by a periodic grating substrate. By exact numerical calculation we demonstrate that substantial short‐circuit current gains are realizable in thin‐film amorphous silicon (a‐SiHx) solar cells. In particular, for a 0.5‐μm‐thick a‐SiHx solar cell, optimal texturing of an Ag substrate to form a one‐dimensional reflective grating can yield a 2‐mA/cm2 enhancement over the flat substrate case. For a two‐dimensional cross‐hatched grating substrate the enhancement is estimated to be 3.5–4 mA/cm2.
TL;DR: Li/Li3.6Si0.4O4/TiS2 has been studied and cell performance evaluated in this paper, where the electrolyte thin film developed was amorphous, ionic conductivity was 5×10−6 (ohm cm)−1 and its Li+ transference number was 1.0.
TL;DR: In this article, a method and apparatus for thin film thickness measurements with thermal waves in which heating and detection laser beams are focused onto the film, normal to the surface of the film with the two beams parallel and non-coaxial.
Abstract: A method and apparatus for thin film thickness measurements with thermal waves in which heating and detection laser beams are focused onto the film, normal to the surface of the film, with the two beams parallel and non-coaxial.
Patent•
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TL;DR: In this paper, individual panels of solar cells are stacked one on top of the other and arranged so that incident light passes through each of the arrays of cells in each panel striking the one below it.
Abstract: Individual panels of solar cells are stacked one on top of the other and arranged so that incident light passes through each of the arrays of cells in each panel striking the one below it. The solar cells in each panel are selected to have a predetermined and different spectral response and thus are responsive to different frequencies of light. Electrical connection is individually made to each of the panels to collect the electrical energy generated from conversion of the light incident on the particular array of cells. Each of the panels may independently be constructed from microcrystalline thin films, amorphous silicon, single crystal silicon, compound semi-conductors, and the like. Individual panels may be constructed of the same semi-conductor material but compositionally modified to provide sensitivity to different portions of the light spectrum.
TL;DR: In this paper, a method for determination of the optical constants of a variety of coating materials is described based on the use of an optical thin film synthesis program to adjust the constants of dispersion equations until a good fit is obtained between measured and calculated spectral transmittance and or reflectance curves.
Abstract: A versatile method for determination of the optical constants is described that can be applied to a variety of coating materials. It is based on the use of an optical thin film synthesis program to adjust the constants of dispersion equations until a good fit is obtained between measured and calculated spectral transmittance and/or reflectance curves. The sensitivity of the determination can be increased by a suitable combination of measurement quantities. Because more than the minimum amount of data can be used, sensitivity to measurement errors and the chances of obtaining multiple solutions can both be reduced. To illustrate the method optical constants are determined of MgF2, ZnS, MgO, Inconel, and Si films in the visible part of the spectrum and of ITO films in the 0.4–12.0-μm range.
Patent•
09 Feb 1983
TL;DR: In this paper, a piezoelectric composite thin-film resonator has been proposed, which has good temperature stability and resonance response, in a fundamental thickness-extensional vibration mode.
Abstract: A piezoelectric composite thin-film resonator has good temperature stability and resonance response, in a fundamental thickness-extensional vibration mode. Spurious vibrations caused by even-number order harmonic overtones are suppressed. The resonator has a thin film of SiO2 or other materials having a resonant frequency temperature coefficient which is opposite to that of the piezoelectric material. The SiO2 layer is inserted between two thin films of ZnO, CdS, AlN, or other piezoelectric materials. This sandwiched structure is positioned between a pair of electrode films and is supported by an insulative or a semiconductive film which is in turn fixed to a substrate. The thicknesses of the thin films have values such that an overall temperature coefficient of the resonant frequency may be at or near substantially zero. In order to better remove the even-number order harmonics, it is preferable to cover the upper electrode film with a thin film of semiconductor or insulator material.
TL;DR: In this article, the authors used a heated disc that rotates the silicon substrate to produce thin films of TiO2 by chemical vapour deposition (CVD) involving the hydrolysis of TiCl4.
TL;DR: In this article, the intrinsic stress, elastic bulk modulus, and yield strength of thin films have been determined by measuring the deformation versus pressure of circular membranes of the materials, and it has been shown that the stress measurement technique can be extended to measure accurately the intrinsic stresses of thin film deposited onto SiNx membranes.
Abstract: Intrinsic stress, elastic bulk modulus, and yield strength of thin films has been determined by measuring the deformation versus pressure of circular membranes of the materials. Low pressure chemical vapor deposited (LPCVD) silicon‐rich silicon nitride (SiNx) has been extensively characterized and found to have an intrinsic stress of ∼1×109 dyn/cm2 and a bulk modulus of ∼1.9×1012 dyn/cm2. A SiNx membrane 1.0 cm in diameter and 1.0 μm thick has been found to survive a differential pressure of 470 Torr with no measurable plastic deformation. Experimental data for several different types of silicon nitride membranes is given. It is shown that the stress measurement technique can be extended to measure accurately the intrinsic stress of thin films deposited onto SiNx membranes.
TL;DR: The angular widths of the observed resonance in silver and aluminum films are both reduced by over an order of magnitude relative to that associated with the Kretschmann excited mode.
Abstract: We report the first observation to our knowledge of a sharp minimum in the attenuated total reflectivity of a thin metal film between index-matching layers. The resonance is due to the excitation of the long-range surface-plasmon mode on both sides of the thin metal films, as originally discussed by Sarid [Phys. Rev. Lett. 47, 1927 (1981)]. The angular widths of the observed resonance in silver and aluminum films are both reduced by over an order of magnitude relative to that associated with the Kretschmann excited mode.