摘要:

A new, simple and highly sensitive spectroscopic method, calorimetric absorption spectroscopy (CAS), for direct detection of phonons emitted via nonradiative recombination processes of charge carriers bound to defects or impurities in solids is demonstrated. Electronic levels of these centers are populated by resonant excitation with monochromatic light. The phonons emitted during recombination are detected with a low‐temperature calorimeter with a sensitivity of ≊10−12J. Thus absorption coefficients as low as ≊10−7cm−1and quantum efficiencies can be determined without using radiation detectors. CAS spectra of N‐  and S‐doped GaP are presented, and the low‐temperature internal quantum efficiency of the nitrogen bound exciton is found to be close to 100%.

ISSN:0003-6951    

DOI:10.1063/1.92137

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Preliminary observations are presented, which show conclusively that when dissociated dislocations glide in InP, and by direct implication other materials with the zinc blende or diamond cubic crystal lattice, they retain their extended configuration. The observations further indicate that the moving Shockley partial dislocations do tend to lie along certain preferred directions.

ISSN:0003-6951    

DOI:10.1063/1.92138

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The first use of an ion beam to dope a silicon specimen by implantation and to anneal it in a single operation is reported. Experimental conditions as well as electrical and structural characterizations of self‐annealed specimens are presented.

ISSN:0003-6951    

DOI:10.1063/1.92139

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A theory of unipolar current over triangular barriers in semiconductor structures is developed. Diodes based on such barriers have been recently fabricated by molecular beam epitaxy using either variable‐gap or modulation‐doped semiconductors. In these diodes the current is due to unipolar injection of electrons. Exact analytic expression for current‐voltage characteristics is obtained. Comparison is made with recent experimental data.

ISSN:0003-6951    

DOI:10.1063/1.92140

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A new method has been developed to form ap+‐npolycrystalline‐crystalline junction at low temperature. The technique involves the use of ane‐beam evaporated polycrystalline silicon‐aluminum‐polycrystalline silicon multilayer structure to obtain an Al‐rich polycrystalline film by heat treatment at 600 °C. Experimenal evidence indicates that the current conduction is dominated by electron recombination at the interface between the polycrystalline silicon and the substrate. The best fit between a simple model and expeirmental data yields an effective recombination velocity of 5×104cm/sec, a value consistent with carrier recombination at the grain boundaries of polycrystalline silicon.

ISSN:0003-6951    

DOI:10.1063/1.92141

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Diffusion of B has been carried out inn‐type solar grade poly‐ and single‐crystalline silicon from a paint on source at 1075 °C for 10 min. From the measurements of the sheet conductivity versus depth, the dopant profiles were evaluated. Within the experimental errors the surface concentration is the same for both poly and single crystal, viz., 1.8×1020atoms cm−3. However, the junction depth is greater by about 850 A˚ in polycrystalline silicon than in single crystal. The shape of the profile observed in polycrystalline silicon is also quite different and this difference is attributed to fast diffusion through grain boundaries. The particular shape of the profile observed in polycrystalline silicon is more suited to solar cell fabrication than the shape of the profile in single crystal.

ISSN:0003-6951    

DOI:10.1063/1.92142

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The fabrication of Schottky‐gate field‐effect transistors (FET’s) on InGaAs lattice matched to InP is reported. A higher band‐gap interface layer is used to lower the gate leakage to acceptable levels. A technique to deduce the effective saturated electron drift velocity is given, which shows over a factor of 2 higher saturated velocity for InGaAs in comparison to GaAs when used as a FET material.

ISSN:0003-6951    

DOI:10.1063/1.92143

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Millimeter‐wave power is generated from ann+/pHg0.74Cd0.26Te photovoltaic diode illuminated by two CO lasers of 5.467‐ and 5.478‐&mgr;m wavelengths, respectively. The output frequency is determined by the laser line separation to be 110 GHz. A maximum power of 0.75 &mgr;W is observed when the diode is dc biased at 0.5 V in the reverse direction.

ISSN:0003-6951    

DOI:10.1063/1.92144

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We have obtained the various types of I‐V characteristics measured experimentally and in analog simulations, by merely changing the junction and the microwave parameters within the same resistively shunted junction model with purely sinusoidal current‐phase relation. It was found that the subharmonic steps do exist in the limit &bgr;c→0, though they can have finite rounding without thermal noise. The statistical properties of the ’’chaotic’’ solutions wer e discussed and their effective temperature was defined and calculated.

ISSN:0003-6951    

DOI:10.1063/1.92145

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Relationships among Hugoniot pressure, effective viscosity, and strain rate under conditions of steady‐wave shock compression are predicted based on the assumption of invariance of a shock property equal to the product of the energy dissipated in shock compression and the rise time of the steady wave. Effective viscosity is found to decrease as &eegr;∼&egr;˙−1/2, while strain rate increases as &egr;˙∼p4hwith Hugoniot pressure. These results are consistent with steady‐wave profile measurements on aluminum.

ISSN:0003-6951    

DOI:10.1063/1.92146

出版商:AIP    

年代:1981

数据来源: AIP