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Showing papers in "Applied Physics Letters in 1976"


Journal ArticleDOI
TL;DR: In this article, thin film solar cells, ∼ 1 μm thick, have been fabricated from amorphous silicon deposited from a glow discharge in silane, and the cells were made in a p i n structure by using doping gases in the discharge.
Abstract: Thin film solar cells, ∼1 μm thick, have been fabricated from amorphous silicon deposited from a glow discharge in silane. The cells were made in a p‐i‐n structure by using doping gases in the discharge. The best power conversion efficiency to date is 2.4% in AM‐1 sunlight. The maximum efficiency of thin‐film amorphous silicon solar cells is estimated to be ∼14–15%.

1,158 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the stresses in aluminum thin films on TiN by transmission x-ray topography and found that the stresses are more compressive in the anode regions.
Abstract: Stresses in aluminum thin films on TiN were studied in situ by transmission x‐ray topography. Stress gradients were seen to build up in thin aluminum films during passage of electrical currents. The stresses are more compressive in the anode regions. These stress gradients seem to be a concomitant of the backflow responsible for the reported threshold in electromigration, and can probably be correlated quantitatively with it.

478 citations


Journal ArticleDOI
TL;DR: In this article, the first compound nucleated in planar binary reaction couples is the most stable congruently melting compound adjacent to the lowest temperature eutectic on the bulk equilibrium phase diagram.
Abstract: What is the first compound that nucleates in planar solid silicon–transition‐metal binary couple reactions whose members form bulk equilibrium compounds? We propose, for couples annealed at low temperatures, the following simple rule: The first compound nucleated in planar binary reaction couples is the most stable congruently melting compound adjacent to the lowest‐temperature eutectic on the bulk equilibrium phase diagram. The predictions of this rule are compared with experimental results.

437 citations


Journal ArticleDOI
TL;DR: In this paper, a method for the measurement of the concentration of hydrogen versus depth in solids using the 1H+15N resonant nuclear reaction is discussed, which has a typical depth resolution of 50-100 A, can be used to a depth of several microns, and can measure hydrogen in concentrations of one part per thousand or greater.
Abstract: A method for the measurement of the concentration of hydrogen versus depth in solids using the 1H+15N resonant nuclear reaction is discussed. This method has a typical depth resolution of 50–100 A, can be used to a depth of several microns, and can measure hydrogen in concentrations of one part per thousand or greater.

341 citations


Journal ArticleDOI
TL;DR: In this paper, the photoelectrolysis of water in cells with SrTiO3 anodes has been confirmed, and the maximum external quantum efficiency at zero bias voltage is 10% (at hν=3.8 eV), about an order of magnitude higher than the maximum value obtained with anodes of TiO2, the only other material so far known to catalyze photoelectronry, and in agreement with the energy level model proposed previously, the efficiency is increased because the band bending at the anode surface is about 0.2 eV larger for
Abstract: The photoelectrolysis of water in cells with SrTiO3 anodes has been confirmed. The maximum external quantum efficiency at zero bias voltage is 10% (at hν=3.8 eV), about an order of magnitude higher than the maximum value obtained with anodes of TiO2, the only other material so far known to catalyze photoelectrolysis. In agreement with the energy‐level model proposed previously, the efficiency is increased because the band bending at the anode surface is about 0.2 eV larger for SrTiO3 than for TiO2, as a result of the smaller electron affinity of SrTiO3.

313 citations


Journal ArticleDOI
TL;DR: An energy level scheme for heterotype and homotype p−n photoelectrolysis cells is presented in this article, which explains the enhanced efficiency of photo-electriclysis with solar radiation.
Abstract: The efficiency of photoelectrolysis with solar radiation can be greatly enhanced by using simultaneously illuminated n‐ and p‐type electrodes. An energy level scheme for heterotype and homotype p‐n photoelectrolysis cells is presented which explains the enhanced efficiency. Data are presented for the homotype n‐GaP/p‐GaP and the heterotype n‐TiO2/p‐GaP systems which support the energy model. H2 and O2 are produced in the n‐TiO2/p‐GaP cell without the need of an external anodic bias.

303 citations


Journal ArticleDOI
TL;DR: In this article, a contamination resist pattern is written with a 5.A 45-keV scanning electron beam in a 100-A-thick Au-Pd film supported by a carbon foil.
Abstract: Metal structures 100 A high with sharply defined linewidths of 80 A have been produced using an electron‐beam fabrication process. A contamination resist pattern is written with a 5‐A 45‐keV scanning electron beam in a 100‐A‐thick Au‐Pd film supported by a 100‐A carbon foil. The unprotected Au‐Pd is removed by dc ion etching with 1‐keV Ar ions. Unlike most electron‐beam microfabrication processes, the resolution of the resulting structure is not limited by electron scattering, but by the grain size of the metal films. These structures should have direct application in a large number of device fabrication problems in electron and x‐ray beam technology and they should provide masks for other microfabrication processes such as x‐ray lithography.

298 citations


Journal ArticleDOI
TL;DR: In this article, X-ray and electron beam diffraction analyses have been carried out on thin films deposited from a beam of carbon ions, and results show that the films consist of a polycrystalline background of cubic diamond with a particle size of 50-100 A with single-crystal regions up to 5 μm in diameter.
Abstract: X‐ray and electron beam diffraction analyses have been carried out on thin films deposited from a beam of carbon ions. Results show that the films consist of a polycrystalline background of cubic diamond with a particle size of 50–100 A with single‐crystal regions up to 5 μm in diameter.

296 citations


Journal ArticleDOI
TL;DR: In this paper, a broad-band continuum source for nanosecond time-resolved excited-state spectroscopy has been described, which has a bandwidth of several thousand cm−1 in the visible with a total power ∼ 1 kW.
Abstract: A new nanosecond broad‐band continuum source is described. The continuum is generated by nonlinear optical processes in fiber waveguides pumped with a 20‐kW 10‐ns dye‐laser pulse of broad spectral width (∼150 A). The continuum has a bandwidth of several thousand cm−1 in the visible with a total power ∼1 kW. The new continuum is in many aspects superior to previously known continuum sources for nanosecond time‐resolved excited‐state spectroscopy.

276 citations


Journal ArticleDOI
TL;DR: In this article, room temperature cw operation has been achieved for stripe geometry double-heterostructure Ga0.12In0.88As0.23P0.77/InP diode lasers emitting at 1.1 μm.
Abstract: Room‐temperature cw operation has been achieved for stripe‐geometry double‐heterostructure Ga0.12In0.88As0.23P0.77/InP diode lasers emitting at 1.1 μm. The heterostructures were grown by liquid‐phase epitaxy on melt‐grown InP substrates, and stripes were defined by using proton bombardment to produce high‐resistance current‐confining regions.

265 citations


Journal ArticleDOI
TL;DR: In this paper, the fabrication procedures and characteristics of several thin-film p−CuInSe2/n−CdS heterojunction solar cells are presented, and two modes of operation (illumination through CdS or through InSe2) are discussed, under 100 mW/cm2 tungsten-halogen illumination for 1.2
Abstract: The fabrication procedures and characteristics of several thin‐film p‐CuInSe2/n‐CdS heterojunction solar cells are presented. Two modes of operation (illumination through CuInSe2 or through CdS) are discussed. Efficiencies in the range of 4–5% are reported, under 100 mW/cm2 tungsten‐halogen illumination for 1.2‐cm2 devices. Included are the spectral response and J‐V characteristics for these photovoltaic junctions.

Journal ArticleDOI
TL;DR: In this paper, the regrowth of Si crystal from amorphous layers created by Si implantation into 〈111〉, ¼ 100 ¼ and ¼ 110 ¼ Si was studied.
Abstract: The regrowth of Si crystal from amorphous layers created by Si implantation into 〈111〉, 〈100〉, and 〈110〉 Si was studied. Channeling effect measurements show that the growths on the 〈110〉 and 〈100〉 substrates are epitaxial and linear with time. For the 〈111〉 samples the growth at 550 °C was significantly slower and nonlinear in time and the regrown layer contained a high concentration of defects. TEM micrographs indicate the presence of stacking faults and/or microtwins in the 〈111〉 samples.

Journal ArticleDOI
TL;DR: In this paper, the effects of an impulse and adiabatic manipulation on the dynamics of a sphere were studied from atmospheric pressure down to ∼10−6 Torr, and the calculated time for an oscillating particle to decay to half-amplitude due to the intrinsic optical damping at zero pressure is ∼0.7 years.
Abstract: Optical levitation of highly transparent particles has been observed in the high‐vacuum regime where viscous damping and thermal conductivity are small, the particle is cooled only by thermal radiation, and radiometric forces are negligible. The effects of an impulse and adiabatic manipulation on the dynamics of a sphere were studied from atmospheric pressure down to ∼10−6 Torr. The calculated time for an oscillating particle to decay to half‐amplitude due to the intrinsic optical damping at zero pressure is ∼0.7 years.

Journal ArticleDOI
TL;DR: In this paper, an electrical signal, resulting from discrete optical absorptions, has been observed for a variety of elements, including several for which such an effect had not been previously reported.
Abstract: An electrical signal, resulting from discrete optical absorptions, has been observed for a variety of elements, including several for which such an effect had not been previously reported. In the present case, the effect is observed as a change in the voltage across a gas discharge tube produced by irradiation with a laser tuned to the wavelength of a transition of a species in the discharge. This signal may be used—without optical detection apparatus—for spectroscopic investigations or analytical determinations of materials in the discharge. Signals were obtained for transitions of lithium, sodium, calcium, barium, uranium, neon, and helium, in commercial hollow cathode lamps, and neon and helium in conventional discharge tubes.

Journal ArticleDOI
TL;DR: In this article, the conduction band edge discontinuity ΔEc = 0.56 eV at n−CdS/p−InP junctions is reported, and the performance of this discontinuity and others are compared with photoemission data and with Van Vechten's extension of these data to many tetrahedrally coordinated semiconductors.
Abstract: The discontinuity ΔEc=0.56 eV in the conduction band edge at n‐CdS/p‐InP junctions is reported. This discontinuity and others are compared with photoemission data and with Van Vechten’s extension of these data to many tetrahedrally coordinated semiconductors. Agreement between measured discontinuities and theoretical predictions is very good. Predictions are made for band parameters pertinent to interfaces involving AIIBIVCV2 compounds with zinc blende, chalcopyrite, or wurtzite crystal structures.

Journal ArticleDOI
TL;DR: In this paper, an automatic fringe counting interferometer with real-time wavelength readout for cw laser sources is described, and absolute wavelength accuracy is demonstrated with saturated absorption spectroscopy in neon.
Abstract: We describe an automatic fringe‐counting interferometer with real‐time wavelength readout for cw laser sources. Sub‐Doppler absolute wavelength accuracy (∼2×10−7) is demonstrated with saturated absorption spectroscopy in neon.

Journal ArticleDOI
TL;DR: In this article, an experimental electro-optical switched directional coupler is reported which is formed in LiNbO3 by diffused Ti strip waveguides and uses stepped reversed phase mismatching to provide electrical adjustment of both switch states.
Abstract: An experimental electro‐optical switched directional coupler is reported which is formed in LiNbO3 by diffused Ti strip waveguides and uses stepped reversed phase mismatching to provide electrical adjustment of both switch states. A measured 400:1 conversion of light from one guide to the other was obtained.

Journal ArticleDOI
TL;DR: In this paper, it was shown that a Fabry-Perot interferometer filled with a Kerr medium has a multiple-valued transmission intensity characteristic, and a simple but accurate approximate theory was described.
Abstract: We show that a Fabry‐Perot interferometer filled with a Kerr medium has a multiple‐valued transmission‐intensity characteristic. ’’On’’ and ’’off’’ field for bistable operation are estimated, and a simple but accurate approximate theory is described.

Journal ArticleDOI
TL;DR: In this paper, the best known photorefractive sensitivity for read-write volume holographic storage (S−1≃300 μJ/cm2) combined with high quality image reconstruction was identified.
Abstract: Bi12SiO20 and Bi12GeO20 present the best known photorefractive sensitivity for read‐write volume holographic storage (S−1≃300 μJ/cm2) combined with high‐quality image reconstruction. Recording processes by photocarrier diffusion (no applied field) and by photocarrier drift are identified. The high photosensitivity is attributed to photocarrier displacements comparable to or larger than fringe spacings. Saturation diffraction efficiency at light power densities larger than 600 μW/cm2 at λ=514.5 nm occurs from complete photocarrier trap filling.

Journal ArticleDOI
TL;DR: In this article, the Schottky barrier was used in thin-film amorphous-silicon solar cells and the current-voltage characteristics were studied in the range from 270 to 370°K and were found to be in agreement with the diffusion theory of metal-semiconductor rectification.
Abstract: Metal–amorphous‐silicon Schottky barriers, similar to those used in thin‐film amorphous‐silicon solar cells, exhibit nearly ideal diode behavior in the dark. The current‐voltage characteristics have been studied in the range from 270 to 370 °K and are found to be in agreement with the diffusion theory of metal‐semiconductor rectification. Barrier heights, which were measured by two different methods, depend on the metal work function, and barriers as high as ∼1.1 eV are obtained with Pt films.

Journal ArticleDOI
TL;DR: In this article, the interdiffusion coefficient was measured by Auger-electron profiling after annealing the structures under As-rich conditions over the temperature range 850-1100 C, and was found to be extremely small, in the 10−18 cm2/sec region at the lower temperatures.
Abstract: Epitaxial structures composed of thin layers of GaAs and AlAs were grown by the technique of molecular beam epitaxy. The interdiffusion coefficient was measured by Auger‐electron profiling after annealing the structures under As‐rich conditions over the temperature range 850–1100 °C. This coefficient was found to be extremely small, in the 10−18 cm2/sec region at the lower temperatures. It also depends on the alloy composition, decreasing with an increase in Al. Such dependence becomes stronger at higher temperatures, giving rise to activation energies of 4.3 and 3.6 eV in the limits of GaAs and AlAs, respectively.

Journal ArticleDOI
TL;DR: In this paper, the authors used velocity interferometry and double-pulse holography to study material ejected from surfaces which are impulsively loaded with plane shock waves and found that a total mass of about 3 μg/cm2 was ejected when the shock arrived at the surface in the present experiments.
Abstract: Velocity interferometry and double‐pulse holography have been used to study material ejected from surfaces which are impulsively loaded with plane shock waves. Experiments performed on aluminum shocked to 25 GPa (250 kbar) provide the average mass and velocity distribution as well as the spatial distribution of material ejected from the surface. A total mass of about 3 μg/cm2 was ejected when the shock arrived at the surface in the present experiments, and a substantial part of this material resulted from jetting at small pits on the surface.

Journal ArticleDOI
TL;DR: In this article, an optical fiber ring resonator was used for the observation of efficient continuous-wave Brillouin laser action in an optical-fiber ring resonance, achieving internal laser conversion efficiencies of 50% and a Brillour-shifted output of 20 mW.
Abstract: The observation of efficient continuous‐wave Brillouin laser action in an optical‐fiber ring resonator is reported. Internal laser conversion efficiencies of 50% and a Brillouin‐shifted output of 20 mW have been achieved.

Journal ArticleDOI
TL;DR: Within the framework of classical beam theory it was shown that a strain independent surface stress has no effect on the natural frequency of a thin cantilever beam as discussed by the authors, therefore, the experimental results of Lagowski, Gatos, and Sproles must have a different explanation.
Abstract: Within the framework of classical beam theory it is shown that a strain‐independent surface stress has no effect on the natural frequency of a thin cantilever beam Therefore, the experimental results of Lagowski, Gatos, and Sproles must have a different explanation

Journal ArticleDOI
TL;DR: In this article, a new dislocation climb model for compound semiconductors with the zinc blende structure is proposed, and the defect structures produced during degradation of Ga1−xAlxAs/GaAs (DH) lasers and GaP greenlight-emitting diodes.
Abstract: A new dislocation climb model is proposed for compound semiconductors with the zinc blende structure. Within the model a supersaturation of only one type of point defect is needed for the dislocation climb process. Consideration of the forces involved suggest that in compound semiconductors grown by liquid‐phase epitaxy, interstitial climb is favored. A trail of vacancy defects is then expected to result from the climb process. Experimental observations in support of this model are presented for the case of the defect structures produced during degradation of Ga1−xAlxAs/GaAs (DH) lasers and GaP green‐light‐emitting diodes.

Journal ArticleDOI
TL;DR: In this paper, the electron-donor effects of boron and phosphorus are clearly seen for the first time; each atom of these metalloids gives ∼1.6 and 2.4 electrons, respectively, to the TM d bands.
Abstract: Continuously cast metallic glasses [METGLASR (trademark of the Allied Chemical Corporation) alloys] based on the transition metals (TM) iron, cobalt, and nickel can now be synthesized containing boron as the only metalloid. The different electron‐donor effects of boron and phosphorus are clearly seen for the first time; each atom of these metalloids gives ∼1.6 and 2.4 electrons, respectively, to the TM d bands. Extrapolation of the available magnetic moment data suggests a nonzero moment on nickel in (TM)80B20 glasses. The boron‐containing metallic glasses generally show higher Curie temperatures and room‐temperature saturation magnetizations than mixed‐metalloid glassy alloys of the same TM content.

Journal ArticleDOI
TL;DR: The photovoltaic properties of Schottky barrier solar cells made from thin films (100-1000 A) of the organic dye hydroxy squarylium have been studied as discussed by the authors.
Abstract: The photovoltaic properties of Schottky barrier solar cells made from thin films (100–1000 A) of the organic dye hydroxy squarylium have been studied. Amorphous and polycrystalline films, prepared by evaporation and solution casting, have strong absorption over the entire visible spectrum. The highest power conversion efficiency measured under AMO white light was 0.1% (0.14 mW/cm2 input intensity); this decreased to 0.02% at 135 mW/cm2. The decrease in η with intensity is characteristic of organic materials, but is usually much more pronounced. For 8500‐A monochromatic light the quantum efficiency was as high as 2.3% and the conversion efficiency was 0.2% (1 mW/cm2).

Journal ArticleDOI
TL;DR: In this article, the dielectric constants of GaAs, CdTe, and ZnSe and their temperature dependences were found from low-frequency capacitance measurements.
Abstract: The dielectric constants of GaAs, CdTe, and ZnSe and their temperature dependences were found from low‐frequency capacitance measurements. From 100 to 300 °K the dielectric constants vary linearly with temperature. No electric field dependence was found up to 104 V/cm, nor frequency dependence between 20 Hz and 1 MHz. The dielectric constants extrapolated linearly to 0 °K are 12.35±0.09, 10.31±0.08, and 8.80±0.07 for GaAs, CdTe, and ZnSe, respectively. The temperature coefficients λ (≡e (0)−1 de/dt) are 2.01×10−4/°K, 2.27×10−4/°K, and 1.71×10−4/°K, respectively, with an accuracy of ±0.02×10−4/°K.

Journal ArticleDOI
TL;DR: In this article, a new technique for use in coherent anti-Stokes Raman scattering experiments allows the simultaneous generation of an entire Q-branch spectrum of the anti-stokes radiation from a molecular gas using a single laser pulse.
Abstract: A new technique for use in coherent anti‐Stokes Raman scattering experiments allows the simultaneous generation of an entire Q‐branch spectrum of the anti‐Stokes radiation from a molecular gas using a single laser pulse. With this technique the stringent requirements of the previous techniques concerning laser linewidth and frequency stability are significantly relaxed. The excellent temporal resolution (20 nsec) makes the technique very attractive for temperature and concentration measurements of molecular gases, even in nonstationary media.

Journal ArticleDOI
TL;DR: In this article, a technique based on nonlinear optical mixing is described for modal phase equalization and recovery of a transmitted image, which limits image transmission in optical fibers to distances too short to be of general interest.
Abstract: Modal phase dispersion limits image transmission in optical fibers to distances too short to be of general interest. A technique based on nonlinear optical mixing is described for modal phase equalization and recovery of a transmitted image.