摘要:

An extension of the Kronig–Penney model to treat mixings of different valleys in superlattices is presented. The value of the mixing parameter &agr; used in the model is deduced by comparison with more sophisticated theory and various experiments for the GaAs/AlAs material system. It is shown that with the use of a single value for the mixing parameter, this simple and efficient model can reasonably reproduce the important aspects of valley mixing effects in GaAs/AlAs superlattices over a wide range of layer thicknesses.

ISSN:0021-8979    

DOI:10.1063/1.354349

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

We report a post‐metallization annealing study of very thin oxide (2.4–3.2 nm), aluminum gate metal‐tunnel oxide‐(p) silicon devices. Voltage dependence measurements of both tunnel current and high‐frequency capacitance as functions of anneal time and temperature reveal that annealing the thin oxide devices after metallization leads to a decrease in interface state density, with dynamics which are similar to, though slower than, what has been observed in thicker oxide aluminum gate systems.

ISSN:0021-8979    

DOI:10.1063/1.355311

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Various metals were deposited on luminescent porous silicon (PS) by immersion in metal ion solutions and by evaporation. The photoluminescence (PL) was quenched upon immersion in ionic solutions of Cu, Ag, and Au but not noticeably quenched in other ionic solutions. Evaporation of 100 A˚ of Cu or 110 A˚ of Au was not observed to quench PL. Auger electron spectroscopy performed on samples quenched and then immediately removed from solution showed a metallic concentration in the PS layer of order 10 at.%, but persisting to a depth of order 3000 A˚.

ISSN:0021-8979    

DOI:10.1063/1.354350

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The results of an optimization procedure performed for a continuous wave rf excited sealed CO2waveguide laser are presented. Parameters that affect laser performance, such as the excitation frequency, the gas pressure, and composition, as well as the electrode temperature and different kinds of circuit losses have been analyzed. An output power of 41 W (17.7 kW/l) with an efficiency of 12% has been obtained from an optimized laser with an active length 37 cm.

ISSN:0021-8979    

DOI:10.1063/1.354351

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A recently demonstrated transport mechanism giving rise to novel photovoltaic multiquantum well intersubband infrared detectors is analyzed theoretically. It is shown that optimized photovoltaic devices have detectivities that can be even larger than those of photoconductive ones. In addition, they have a high dynamic range and are particularly suited for the large photon fluxes occurring in the 8–12 &mgr;m regime.

ISSN:0021-8979    

DOI:10.1063/1.354352

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

Structural changes and phase transitions during high dose Si implantation into single crystal Ni(100) and subsequent annealing at temperatures up to 800 °C have been characterized using Rutherford backscattering spectrometry and channeling. A complete amorphous layer is produced after implantation to doses above about 4.5×1017Si/cm2. The recrystallization of the amorphous layer during isochronal annealing leads to the formation of various Ni‐rich silicides at different temperatures. Ion channeling suggests that an epitaxial Ni3Si layer on the Ni(100) substrate can form at a temperature of 400 °C. Further annealing at higher temperatures up to 600 °C improves the epitaxial quality, as indicated by a channeling minimum yield &khgr;minof 8% in the Ni3Si layer. Higher temperature annealing at 700 °C and above results in the dissolution of the Ni3Si layer into the Ni substrate.

ISSN:0021-8979    

DOI:10.1063/1.354353

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

It is suggested that a perpendicular magnetic field can strongly suppress the most important nonradiative intersubband transition processes, namely Auger recombination and optical phonon transitions, in an intersubband infrared laser device that has recently been proposed using multiple quantum wells. The present analysis suggests that the fabrication of such a novel laser device is quite realistic using present III‐V technologies.

ISSN:0021-8979    

DOI:10.1063/1.354354

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The output of a commercial picosecond Ti:sapphire laser is mixed with the 514.5 nm line of a continuous wave Ar+laser to produce 1.4 ps pulses between 1.295 and 1.7 &mgr;m. Noncritical temperature tuning of LiB3O5has a number of advantages over the other two applicable crystals: &bgr;‐BaB2O4and KTiOPO4. The infrared pulse durations are measured by parametric amplification in KTiOPO4.

ISSN:0021-8979    

DOI:10.1063/1.354327

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A new method to bond a quartz crystal onto a silicon substrate, fabricating a quartz‐crystal‐on‐silicon resonator, is reported together with its fabrication process, interface microstructure, and resonant characteristics. A one‐chip quartz crystal oscillator employing the quartz‐crystal‐on‐silicon resonator for mobile communication is also suggested.

ISSN:0021-8979    

DOI:10.1063/1.354328

出版商:AIP    

年代:1993

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.354309

出版商:AIP    

年代:1993

数据来源: AIP