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Results for “semiconducting”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Unique intermetallic compounds prepared by shock wave synthesis

Technique compresses fine ground metallic powder mixture beyond crystal fusion point. Absence of vapor pressure voids and elimination of incongruous effects permit application of technique to large scale fabrication of intermetallic compounds with specific characteristics, e.g., semiconduction, superconduction, or magnetic properties.

Otto, G.↗
NASA NTRS1967

Miniature stress transducer Patent

Miniature solid state, direction sensitive, stress transducer design with bonded semiconductive piezoresistive element for sensing residual stresses

San Miguel, A.↗
NASA NTRS1972

Investigation of superconducting interactions and amorphous semiconductors

Research papers on superconducting interactions and properties and on amorphous materials are presented. The search for new superconductors with improved properties was largely concentrated on the study of properties of thin films. An experimental investigation of interaction mechanisms revealed no new superconductivity mechanism. The properties of high transition temperature, type 2 materials prepared in thin film form were studied. A pulsed field solenoid capable of providing fields in excess of 300 k0e was developed. Preliminary X-ray measurements were made of V3Si to determine the behavior of cell constant deformation versus pressure up to 98 kilobars. The electrical properties of amorphous semiconducting materials and bulk and thin film devices, and of amorphous magnetic materials were investigated for developing radiation hard, inexpensive switches and memory elements.

Janocko, M. A.↗
NASA NTRS1972

Precise measurement of charged defects in III-V compounds (2)

The main objective of this research is to obtain a calibration of a low concentration of charged defects in some III-V semiconducting compounds. The experimental technique being used is nuclear magnetic resonance (NMR), and the objective is to be attained through a thorough examination of the properties of the NMR lines of the nuclei in the III-V compounds. The properties of the NMR lines, and how they are influenced by the presence of charged defects are studied theoretically and experimentally.

Soest, J. F.↗
NASA NTRS1972

Improvements in solid state radiographic converter screens.

Description of two different kinds of solid-state radiographic converter screens which have been developed. After briefly reviewing the working principles of the solid-state image converter - a sandwich type structure consisting of a photoconductive layer and an electroluminescent layer with a semiconductive layer and a black layer between them, two different kinds of radiographic converter screens are described - a radiographic amplifier screen that can be used as a substitute for the fluoroscopic screen, and a radiographic storage screen that can be used instead of radiographic films. The construction of both kinds of converters is fundamentally the same, the only difference being in the sensing photoconductive material. The radiographic amplifier screen has a moderately fast response, while the radiographic storage screen displays the image long after the irradiation is stopped.

Szepesi, Z.↗
NASA NTRS1973

Use of MgF2 and LiF photocathodes in the extreme ultraviolet.

The photoelectric yields of 2000-A thick samples of MgF2 and LiF have been measured at wavelengths in the range from 1216 to 461 A. Peak values of 43 and 34%, respectively, were obtained at wavelengths around 550 A at 45 deg incidence. Coating the cathode of a channel electron multiplier with 3000 A of MgF2 produced no significant deterioration in the electrical properties and increased the sensitivity by factors of 1.62, 2.76, and 2.60 at wavelengths of 742, 584, and 461 A, respectively. Since the stability of response of the MgF2 photocathodes appears to be equal to that of conventional metallic and semiconducting cathodes, it is concluded that MgF2 would be a practical, high-efficiency photocathode for use in the extreme ultraviolet.

Lapson, L. B.↗
NASA NTRS1973

Black silicate paints: Formulation and performance data on OSO-H

Formulations and general procedures are given for making and applying space environmentally, as well as atmospherically stable black silicate paints. Compositions are given which meet spacecraft self-contamination requirements, have excellent heat resistance, and are strongly semiconductive.

Schutt, J. B.↗
NASA NTRS1974

Cold cathodes for sealed-off CO2 lasers

Cold cathodes for CO2 lasers should possess a very low sputtering rate, have a minimum of negative ions in the sputtering products, and consume no oxygen. These conditions can be satisfied by selecting cathode materials from those elements of group I in the periodic table which form semiconducting oxide layers and then exposing these elements to a reducing gas mixture. Experimental results show that silver, internally oxidized silver-copper alloys, and pure copper satisfy most of these requirements in He-CO2-CO-Xe gas mixtures. Infrared CO and CO2 gas analysis performed on simple gas discharge tubes using such cathodes indicate that laser lives of 10,000 hr can be expected.

Hochuli, U. E.↗
NASA NTRS1976

Solar cell grid patterns

A grid pattern is described for a solar cell of the type which includes a semiconductive layer doped to a first polarity and a top counter-doped layer. The grid pattern comprises a plurality of concentric conductive grids of selected geometric shapes which are centered about the center of the exposed active surface of the counter-doped layer. Connected to the grids is one or more conductors which extend to the cell's periphery. For the pattern area, the grids and conductors are arranged in the pattern to minimize the maximum distance which any injected majority carriers have to travel to reach any of the grids or conductors. The pattern has a multiaxes symmetry with respect to the cell center to minimize the maximum temperature differentials between points on the cell surface and to provide a more uniform temperature distribution across the cell face.

Yasui, R. K.↗