摘要:

This letter describes the effect of isochronal anneals on polycrystalline gallium arsenide solar cells, whose grain‐boundary edges have been passivated by selective anodization. Both the deterioration of this anodic oxide with temperature, as well as treatments for its full recovery and stabilization, are outlined in this Letter. This treatment consists of a rinse in strong HCl, and is carried out on cells after they are completely fabricated. It is proposed that conversion of the arsenic oxide component to its more stable hydroxide or chloride takes place during this treatment.

ISSN:0003-6951    

DOI:10.1063/1.92113

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Photoconductive detectors, fabricated fromp‐type In0.53Ga0.47As using strip‐line techniques, exhibit rise and fall times of 45 and 70 psec FWHM. This performance is consistent with a peak electron drift velocity of 2.1×107cm/sec at a field of ∼3.5 kV/cm and represents the fastest reported detector response for the 1.0–1.7‐&mgr;m wavelength range.

ISSN:0003-6951    

DOI:10.1063/1.92114

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Superlattices of InAs‐GaSb have been investigated with layer thicknesses ranging from the onset of the semiconductor‐semimetal transition (<100 A˚) to the heterojunction limit (≳1000 A˚). Pronounced Shubnikov–de Haas osicillations have been observed throughout the entire semimetallic regime which are shown to be associated with the ground‐electron sub‐bands, yielding energies of the Fermi level in agreement with those calculated from electron transfers.

ISSN:0003-6951    

DOI:10.1063/1.92115

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Low‐temperature anodic oxidation in a ’’cold’’ plasma (multipole) of metals like Al or Ta through a thin calcia‐stabilized zirconia (CSZ) film is possible. Thick (≳300 nm) stoichiometric metal oxides are formed under the CSZ with high growth rates (20–30 nm/min). Anodization of bare metals under similar plasma conditions leads to very low oxidation rates (<1 nm/min). The CSZ film, which acts as a selective oxygen filter, has thus greatly enchanced the oxidation rate. Low‐temperature (<50 °C) plasma anodization of silicon (typical rates 2–3 nm/min) is also possible through a thin CSZ film.

ISSN:0003-6951    

DOI:10.1063/1.92116

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Measurements of the current‐voltage characteristics of GaAs‐AlxGa1−xAs heterojunction layers are reported. The experimental results are consistent with the idea of real‐space transfer of the electrons out of the GaAs into the AlxGa1−xAs under hot‐electron conditions. Current saturation and negative differential resistance are observed as predicted by Monte Carlo simulations.

ISSN:0003-6951    

DOI:10.1063/1.92117

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Energy conversion efficiencies as high as 5.96% are reported on polycrystalline transparent magnesium Zn3P2diodes, 0.7 cm2in area, tested under simulated AM1 illumination. The transparent Mg films with low sheet resistivities are obtained by dc sputtering. The effective minority‐carrier diffusion length in Zn3P2is estimated from spectral response measurements and correlates well with the measured short‐circuit current. Loss analysis of the present cells shows a practical upper limit of 9% in conversion efficiency.

ISSN:0003-6951    

DOI:10.1063/1.92124

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A new switching phenomenon in metal‐oxide semiconductor tunnel junction has been discovered. With a sufficiently large negative bias applied to the electrode, incident visible light of intensity greater than about 1 &mgr;W/cm2causes the reverse‐biased junction to switch from a low‐current to a high‐current state. It is believed that hot‐electron‐induced impact ionization provides the positive feedback necessary for switching, and causes the junction to remain in its high current‐state after the optical exciation is removed. The junction may be switched back to the low‐current state electrically. The basic junction characteristics have been measured, and a simple model for the switching phenomenon has been developed.

ISSN:0003-6951    

DOI:10.1063/1.92126

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We present a generalization of the polarization coherent anti‐Stokes Raman spectroscopy to zinc‐blende structure semiconductors. Competitive third‐order processes have been put in evidence by studying the resonant signal around the LO phonon at 292 cm−1in GaAs. Our analysis enables us to compare directly Raman and free‐carrier contributions whose concentration can be thus measured by a purely optical method.

ISSN:0003-6951    

DOI:10.1063/1.92127

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Radiation damage caused by ion implantation is used to control the carrier lifetime in silicon‐on‐sapphire (SOS) films. Photoconductivity measurements show the relaxation time changes by several orders of magnitude and can be as short as 8 ps. The carrier mobility is found to be at least an order of magnitude higher than amorphous silicon materials with similar relaxation times. A photodetector is described that demonstrates the high‐speed capability of these high‐defect‐density films.

ISSN:0003-6951    

DOI:10.1063/1.92128

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Single‐crystal AlN layers have been grown on Si substrates at ∼1200 °C using metalorganic chemical vapor deposition. The metal/AlN/Si MIS structures have been investigated by the MIS conductance method. It was found that the interface‐state densityNssand electron capture cross section &sgr;nin the depletion region are of the order of 1011eV−1cm−2and 10−17cm, respectively.

ISSN:0003-6951    

DOI:10.1063/1.92129

出版商:AIP    

年代:1981

数据来源: AIP