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Results for “P-N JUNCTION”

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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1968

CdTe-HgTe heterostructures.

CdTe-HgTe heterostructures preparation with minimum energy gaps, showing photovoltaic effect caused by undesirable p-n junction due to Cd vacancy formation

Almasi, G. S.↗
NASA NTRS1972

JPL lithium doped solar cell development program

One of the most significant problems encountered in the use of silicon solar cells in space is the sensitivity of the device to electron and proton radiation exposure. The p-diffused-into-n-base solar cells were replaced with the more radiation tolerant n-diffused-into-p-base solar cells. Another advancement in achieving greater radiation tolerance was the discovery that the addition of lithium to n-base silicon resulted in what appeared to be annealing of radiation-induced defects. This phenomenon is being exploited to develop a high efficiency radiation resistant lithium-doped solar cell. Lithium-doped solar cells fabricated from oxygen-lean and oxygen-rich silicon were obtained with average initial efficiencies of 11.9% at air mass zero and 28 C, as compared to state-of-the-art n-p cells fabricated from 10 ohm cm silicon with average efficiencies of 11.3% under similar conditions. Lithium-doped cells demonstrated the ability to withstand three to five times the fluence of 1-MeV electrons before degrading to a power equivalent to state-of-the-art solar cells. The principal investigations are discussed with respect to fabrication of high efficiency radiation resistant lithium-doped cells, including starting material, p-n junction diffusion, lithium source introduction, and lithium diffusion.

Berman, P. A.↗
NASA NTRS1972

GaAs vapor-grown bipolar transistors.

Discussion of an approach for the fabrication of high-temperature GaAs transistors which is centered on the preparation of n-p-n three-layered structures entirely by a vapor-phase growth technique, as described by Tietjen and Amick (1966). The low growth temperature of approximately 750 C is thought to reduce contamination during crystal growth and to contribute to the reasonably high minority-carrier lifetimes obtained for the vapor-grown p-n junctions. The fact that impurity concentrations and layer thicknesses can be precisely controlled for epitaxial layers as thin as 1 micrometer is an important feature of this growth technique.

Nuese, C. J.↗
NASA NTRS1972

Solid state image sensing arrays

The fabrication of a photodiode transistor image sensor array in silicon, and tests on individual elements of the array are described along with design for a scanning system for an image sensor array. The spectral response of p-n junctions was used as a technique for studying the optical-absorption edge in silicon. Heterojunction structures of Sb2S3- Si were fabricated and a system for measuring C-V curves on MOS structures was built.

Sadasiv, G.↗
NASA NTRS1972

AC impedance of silicon solar cells.

The equivalent source impedance of a solar array is an important parameter in the design and analysis of solar array power conditioning equipment. Laboratory impedance tests have been performed on individual silicon solar cells and the test results have been correlated with P-N junction theory as developed by Shockley. The impedance has been broken into resistive and reactive components. The impedance has been expressed as a function of DC operating point and frequency. A practical application of the individual cell characteristics is presented in a solar array simulator design.

Zerbel, D. W.↗
NASA NTRS1972

Development of a (Hg, Cd)Te photodiode detector, Phase 2

High speed sensitive (Hg,Cd)Te photodiode detectors operating in the 77 to 90 K temperature range have been developed for the 10.6 micron spectral region. P-N junctions formed by impurity (gold) diffusion in p-type (Hg, Cd) Te have been investigated. It is shown that the bandwidth and quantum efficiency of a diode are a constant for a fixed ratio of mobility/lifetime ratio of minority carriers. The minority carrier mobility and lifetime uniquely determine the bandwidth and quantum efficiency and indicate the shallow n on p (Hg,Cd) Te diodes are preferable as high performance, high frequency devices.

Source record↗
NASA NTRS1965

GaAs-Si photon-activated switch.

Light activated low level switch consisting of electroluminescent GaAs p-n diode and double emitter silicon transistor

SWITCHING ELEMENT↗