APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

15 Nov 1974

Volume 25, Issue 10, pp. 531-629

Page 1 of 2 Pages Next Page | Jump to Page

Wetting of thin layers of SiO2 by water

Richard Williams and Alvin M. Goodman

Appl. Phys. Lett. 25, 531 (1974); http://dx.doi.org/10.1063/1.1655297 (2 pages) | Cited 53 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
We have measured the contact angle θ of water on silicon and on very thin layers of silicon dioxide grown on silicon. The silicon is hydrophobic and θ is near 90°. Oxides thicker than 30 Å are hydrophilic and θ is near 0°. For intermediate thicknesses, θ varies smoothly between these limits. Our results show that the interaction energy between water and the solid surface depends strongly on the oxide thickness. Consideration of different possible interactions leads us to conclude that this is due to corresponding changes in the structure or composition of the oxide surface.

CdS bolometer for detecting heat pulses in a magnetic field

Takehiko Ishiguro and Shigeo Morita

Appl. Phys. Lett. 25, 533 (1974); http://dx.doi.org/10.1063/1.1655298 (2 pages) | Cited 7 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
The characteristics of a new low‐temperature bolometer, insensitive to magnetic fields, are reported. The bolometer consists of an evaporated CdS film with interdigital electrodes, and the underlying mechanism is attributed to preferential electron‐trapping influences on the dc photoconductivity.

New optical storage mode in liquid crystals

Werner E. L. Haas and James E. Adams

Appl. Phys. Lett. 25, 535 (1974); http://dx.doi.org/10.1063/1.1655299 (3 pages) | Cited 26 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
A novel electrically reversible storage effect in doped nematic liquid crystals is described. The ``off state'' is homeotropic nematic and the ``on state'' a single layer of densely packed spherulites. Both states are stable in time. The effect was observed in a narrow range of pitch and cell thickness combinations, and is interpreted as a nematic‐cholesteric phase transition.

Acoustic surface wave detection of radiative absorption

J. H. Parks, D. A. Rockwell, T. S. Colbert, K. M. Lakin, and D. Mih

Appl. Phys. Lett. 25, 537 (1974); http://dx.doi.org/10.1063/1.1655300 (3 pages) | Cited 6 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
A new technique is presented to study surface absorptive properties by utilizing the interaction of an acoustic surface wave with a radiatively heated surface region. Phase changes are induced in a surface wave on Y‐cut quartz by the absorption of 10.6‐μ laser radiation. Quantitative measurements of the process agree with a theory describing the interaction in which there are no free parameters. The sensitivity and response time of this detection process are indicated by phase change signals occurring in a ∼10‐μ absorbing film which correspond to a radiative heating of ∼13 μJ and have a rise time of ∼125 nsec.

Atomic displacement and ionization effects on the optical absorption and structural properties of ion‐implanted Al2O3

G. W. Arnold, G. B. Krefft, and C. B. Norris

Appl. Phys. Lett. 25, 540 (1974); http://dx.doi.org/10.1063/1.1655301 (3 pages) | Cited 68 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
Ion‐induced lattice atom displacements in single‐crystal Al2O3 give rise to an optical absorption band at 204 nm as well as to expansion of the implanted volume. The 204‐nm absorption per unit energy into atomic processes is found to increase rapidly with decreasing incident ion mass. In contrast, light ions (H+, D+, He+) show less volume expansion per unit energy into atomic processes than do heavier ions. Furthermore, the volume expansion induced by heavy ion implantation can be completely relieved by H+‐ion implantation or by ionizing electron irradiation (8.16 keV). A simple model characterizes the results. The 204‐nm absorption is found to be proportional to the ion energy into electronic processes, and the expansion is proportional to the ion energy into atomic processes linearly reduced by the ion energy into electronic processes. The implications for defect production in CTR insulators are discussed.

Medium homogeneity considerations in low‐Mach‐number flow discharges

J. H. Jacob, H. H. Legner, D. R. Ahouse, and J. Wallace

Appl. Phys. Lett. 25, 542 (1974); http://dx.doi.org/10.1063/1.1655302 (3 pages) | Cited 2 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
Density variations in low‐Mach‐number (≤0.3) flowing discharges have been obtained by coupling the fluid mechanics with the plasmadynamics. The coupling occurs through the variation of the electrical conductivity with density. If this variation is known, for a particular lasing mixture, the simple and accurate analysis presented below may be applied.

Harmonic mixing characteristics of metal‐barrier‐metal junctions as predicted by electron tunneling

S. M. Faris and T. K. Gustafson

Appl. Phys. Lett. 25, 544 (1974); http://dx.doi.org/10.1063/1.1655303 (4 pages) | Cited 12 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
The bias dependence of the nonlinear mixing characteristics of metal‐barrier‐metal junction currents is deduced assuming an electron tunneling model. The difference‐frequency beat voltage at frequency ω1−nω2, where n is an integer and ω1 and ω2 are the assumed frequencies of two induced currents, is found to have n zeros as the diode bias is varied. Recent experimental observations have demonstrated such characteristics.

Correlation of soft x‐ray spots with hard radiation and neutron emission in a 1‐kJ plasma focus

K. H. Schönbach, L. Michel, and Heinz Fischer

Appl. Phys. Lett. 25, 547 (1974); http://dx.doi.org/10.1063/1.1655304 (3 pages) | Cited 14 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
One to four x‐ray spots are always present in hydrogen and deuterium along the z axis during the dense pinch phase; ∼4% argon is required for pinhole photography. Spots have an observed 5–10‐ns lifetime and develop in succession within the first 30 ns of the x‐ray emission. The hard >80‐keV radiation shows the spot time structure and controls the neutron pulse. The x‐ray spots represent m = 0 plasma instabilities.

Secondary electron emission from the GaN:Cs☒O surface

Ramon U. Martinelli and J. I. Pankove

Appl. Phys. Lett. 25, 549 (1974); http://dx.doi.org/10.1063/1.1655305 (3 pages) | Cited 2 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
High secondary emission ratios have been obtained for the GaN:Cs☒O surface. A peak ratio of 51 at 3 keV primary electron energy has been observed. At 20 keV the ratio is 24, compared with 2 when the GaN is uncesiated. Analysis of the data indicates that the diffusion length in the material is between 300 and 800 Å, and the surface escape probability for secondary electrons is 0.36. These results indicate that the GaN:Cs☒O surface has been activated to negative electron affinity (NEA).

Large enthalpy extraction experiments in a nonequilibrium magnetohydrodynamic generator

E. Tate, C. H. Marston, and B. Zauderer

Appl. Phys. Lett. 25, 551 (1974); http://dx.doi.org/10.1063/1.1655306 (3 pages)

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
A measure of the performance of a magnetohydrodynamic (MHD) generator is the enthalpy extraction (power out∕heat in) which generally must exceed 20% to operate efficiently in a thermodynamic Brayton power cycle. For the first time 1.82 MW which represented 19.3% enthalpy extraction was achieved in a nonequilibrium plasma MHD generator. Cold electrodes were used. Theoretical calculations show that 30% enthalpy extraction could be achieved with thermionically emitting electrodes.

Degree of ionization of a high‐temperature plasma

H. A. Hyman

Appl. Phys. Lett. 25, 553 (1974); http://dx.doi.org/10.1063/1.1655307 (3 pages) | Cited 2 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
An approximate method, originally proposed by Raizer for solving the Saha equations, is extended to both the corona limit, as well as to the more general, non‐LTE case, in which both radiative and collisional recombination are important. The method should be useful for obtaining a reliable estimate of the degree of ionization of high‐temperature high‐Z plasmas.

Thermal lens effect in a binary liquid mixture: A new effect

M. Giglio and A. Vendramini

Appl. Phys. Lett. 25, 555 (1974); http://dx.doi.org/10.1063/1.1655308 (3 pages) | Cited 27 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
We present data showing that the thermal lens effect in a binary liquid mixture is noticeably larger than in its two pure constituents. The anomalous effect observed in the mixture is interpreted as a consequence of the buildup of thermally induced concentration gradients (Soret effect). We suggest that the thermal lens technique could be exploited for determining the thermal diffusion ratio kT in binary liquid mixtures.

Impulse produced by the interaction of CO2 TEA laser pulses

J. F. Ready

Appl. Phys. Lett. 25, 558 (1974); http://dx.doi.org/10.1063/1.1655309 (3 pages) | Cited 13 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
This paper describes measurements of the impulse transmitted to metallic targets by CO2 TEA laser pulses with duration around 100 ns. This represents the first such measurements for submicrosecond duration pulses. The impulse was measured as a function of target material and diameter, laser power, laser beam focusing, and ambient air pressure.

A new light modulator using perturbation of synchronism between two coupled guides

Kunio Tada and Keikichi Hirose

Appl. Phys. Lett. 25, 561 (1974); http://dx.doi.org/10.1063/1.1655310 (2 pages) | Cited 20 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
A new device that can be used as a light modulator as well as an optical directional coupler is proposed. It consists of p+,n,n+,n and n+‐type semiconductor layers. Two n‐type layers operate as coupled optical waveguides. The exchange of light power between two coupled waveguides can be controlled by a reverse voltage applied on the p+‐n junction. When the voltage was changed from 0 to 10 V in a GaAs test sample of length 1 mm, the output light power from each guide changed by approximately 15% of the total output light power from the two guides at a wavelength of 1.15 μm.

Light beam scanning and deflection in epitaxial LiNbO3 electro‐optic waveguides

P. K. Tien, S. Riva‐Sanseverino, and A. A. Ballman

Appl. Phys. Lett. 25, 563 (1974); http://dx.doi.org/10.1063/1.1655311 (3 pages) | Cited 10 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
We report a method of scanning and deflecting a light beam in an electro‐optic waveguide of epitaxial LiNbO3 film. The method involves the use of the electro‐optic effect for excitation of a proper distribution of the refractive index which causes the light beam to deflect. The angle of deflection is found to vary continuously with the intensity of the applied field. We are able to scan a light beam in the plane of the film up to 4°. We also present a theory for the light beam deflection and show that our method does optimize the deflection efficiency.

Optical pulse compression

D. Grischkowsky

Appl. Phys. Lett. 25, 566 (1974); http://dx.doi.org/10.1063/1.1655312 (3 pages) | Cited 34 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
Dramatic and controllable reshaping of frequency‐modulated dye laser pulses has been observed. The pulses, nearly resonant with the 2P1∕2 line (7948 Å) of Rb, first passed through a LiNbO3 frequency modulator, and then through a cell containing dilute Rb vapor where the reshaping took place. Large pulse compressions were obtained with only 400 MHz of frequency modulation due to the extremely large frequency dispersion of the group velocity.

Accumulation‐mode charge‐coupled device

Richard D. Nelson

Appl. Phys. Lett. 25, 568 (1974); http://dx.doi.org/10.1063/1.1655313 (3 pages)

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
An accumulation‐mode charge‐coupled device has been fabricated and operated at 4°K. A discussion of device energy band structure, signal‐processing time, and experimental results is presented.

Velocity saturation in n‐type AlxGa1−xAs single crystals

A. A. Immorlica and G. L. Pearson

Appl. Phys. Lett. 25, 570 (1974); http://dx.doi.org/10.1063/1.1655314 (3 pages) | Cited 12 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF


See Also: Erratum

Show Abstract
Current‐versus‐voltage characteristics of bulk n‐type AlxGa1−xAs devices are examined for material compositions 0.27<x<0.43. Preliminary experimental evidence indicates that the electron velocity saturates at a composition xs=0.38±0.02 above a threshold electric field of 2.4 kV∕cm. The carrier saturation velocity is estimated to be 3.3×106 cm∕sec. The direct‐indirect transition of AlxGa1−xAs at 300°K, inferred from transport measurements, is estimated to be in the range 0.45–0.48.

New method to determine the photoionization threshold energy of a deep level from photocapacitance

T. Okumura and T. Ikoma

Appl. Phys. Lett. 25, 572 (1974); http://dx.doi.org/10.1063/1.1655315 (3 pages) | Cited 14 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
A new method is proposed to determine the photoionization threshold energy of a deep level from the dependence of photocapacitance on the scanning rate of light wavelengths. The validity is demonstrated by applying this method to minority carrier traps in an n‐type GaAs and a p‐type GaP. It is shown that Lucovsky's model of photoionization cross section is valid at least in photon energies less than 1.5 times the threshold energy.

Normal laser damage of silicon solar cells without phase change

Y. Matsuoka and A. Usami

Appl. Phys. Lett. 25, 574 (1974); http://dx.doi.org/10.1063/1.1655316 (3 pages) | Cited 12 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
An experimental study has been made of the damage to floating zone (FZ) and pulled (CZ) n∕p‐type silicon solar cells caused by a normal ruby laser. Although the cells were irradiated below the power density at which phase change occurred, the degradation of the normalized short‐circuit current was observed mainly in the long‐wavelength region. This result indicates that some kind of thermal defects are induced by laser quenching. Approximately 60–70% of the laser‐induced defects annealed out at room temperature.

Photoemission and electron energy loss spectroscopy of GeO2 and SiO2

J. E. Rowe

Appl. Phys. Lett. 25, 576 (1974); http://dx.doi.org/10.1063/1.1655317 (3 pages) | Cited 41 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
The electronic structure of GeO2 and SiO2 has been studied by ultraviolet photoemission spectroscopy (UPS) and electron energy loss spectroscopy (ELS) using thermally grown films prepared in ultrahigh vacuum (p ∼ 10−10 Torr). A consistent energy level model of both filled and empty states is constructed from the UPS and ELS data. The filled states correspond to localized bonding or nonbonding O(2p) molecular orbitals. The empty states observed in ELS correspond to excitons formed from either localized antibonding states or more extended ``conduction'' band states.

Production of negative ions and generation of intense neutral beams by laser irradiation

A. Y. Wong, J. M. Dawson, W. Gekelman, and Z. Lucky

Appl. Phys. Lett. 25, 579 (1974); http://dx.doi.org/10.1063/1.1655318 (2 pages) | Cited 6 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
10 A of H− ion current is produced by a CO2 laser on NaH targets. A scheme of resonant detachment of electrons from negative ions by the laser is also discussed.

Short CO2 laser pulse generation by optical free induction decay

Eli Yablonovitch and J. Goldhar

Appl. Phys. Lett. 25, 580 (1974); http://dx.doi.org/10.1063/1.1655319 (3 pages) | Cited 52 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
Short CO2 laser pulses, adjustable in the range between 0.1 and 0.5 nsec, have been produced by a new pulse‐shaping technique. A laser breakdown spark is the active switching element, but the pulse is actually generated by optical free induction decay in a passive linear medium. This approach features simplicity, fast rise time, high contrast ratio, unity switching efficiency, and is suitable as the input to high‐power amplifier stages.

Polycrystalline silicon films on aluminum sheets for solar cell application

P. H. Fang, L. Ephrath, and W. B. Nowak

Appl. Phys. Lett. 25, 583 (1974); http://dx.doi.org/10.1063/1.1655320 (2 pages) | Cited 12 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
In order to make low‐cost silicon solar cells for large‐scale terrestrial use, we have considered a method for growing silicon with a columnar structure, with a monograin along the growth direction. Such a polycrystal, in contrast to general polycrystal material with randomly oriented grain arrangement, would make possible polycrystalline solar cells with good photovoltaic efficiencies.

Operation of an amorphous‐emitter transistor

Kurt E. Petersen, David Adler, and M. P. Shaw

Appl. Phys. Lett. 25, 585 (1974); http://dx.doi.org/10.1063/1.1655321 (3 pages) | Cited 3 times

Online Publication Date: 9 October 2003

Full Text: | Download PDF

Show Abstract
A unique device employing a threshold‐type chalcogenide glass as the emitter of a heterojunction transistor has been fabricated. The device exhibits strikingly different behavior depending on whether the amorphous semiconductor is in the on or off state. The several modes of transistor operation can be explained in terms of recently proposed heterojunction band models. An additional implication of the data is the predominance of electrons rather than holes in the one state of the glass, in direct contrast to the low‐field behavior.
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close