摘要:

In a gas‐microphone cell absorption of modulated light causes oscillating transport of heat and of mass as well. The transport of mass is described by the diffusion equation. The concentration of substance from sample or sorbate at the sample to gas boundary is obtained from the vapor pressure. Introduction of an average molar concentration variation leads to a pressure variation. Results of calculations can explain recently measured data very well. For water at 40 °C oscillating mass transfer contributes the same amount to pressure variation as the heat wave.

ISSN:0003-6951    

DOI:10.1063/1.94873

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The pseudobinary III/V system GaAs1−ySbyis well known to have a solid phase miscibility gap with a critical temperature of 751 °C. We have succeeded in growing epitaxial layers of GaAs0.5Sb0.5lattice matched to InP at temperatures of 600 and 630 °C using the organometallic vapor phase epitaxy technique. The key requirement is a III/V ratio of greater than unity. This leads to the incorporation of all As and Sb reaching the interface and the ability to grow metastable alloys. The epitaxial GaAs0.5Sb0.5layers have excellent surface morphology and efficient photoluminescence at a wavelength of 1.6  &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.94874

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Epitaxialn‐type CdxHg1−xTe layers on (111) CdTe substrates have been grown between 250 and 300 °C by sputtering deposition. The standard growth rate was nominally 2  &mgr;m/h for a thickness range from 10 to 30  &mgr;m. Typical electron concentration in CdxHg1−xTe layers with Cd composition of 0.34 is around of 2×1016cm−3with a Hall mobility of 20 000 cm2 V−1 s−1at 77 K. Films can be converted to  ptype after annealing. We report for the first time the characteristics of backside illuminated 32×32 planar photovoltaic mosaic arrays processed on sputtered layers. Hybrid structures have been fabricated and evaluated; the preliminary results indicate the suitability of these mosaics for hybrid focal plane applications.

ISSN:0003-6951    

DOI:10.1063/1.94875

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Thin silicide layers are found to be formed through solid state reaction between hydrogenated amorphous silicon (a‐Si:H) and metals. The method of formation of the silicide layer is very simple: deposition of metal, annealing, and etching of the residual metal layer. The reaction kinetics and properties of this layer are described. The thickness of this silicide layer is estimated to be less than 100 A˚. Accordingly, it can be used as the semitransparent electrode ina‐Si:H photodiodes. This layer is more chemically stable than such conventional transparent semiconductive oxides as indium tin oxide (ITO). Photodiodes using this semitransparent electrode have as good optical and electrical characteristics as conventionala‐Si:H photodiodes using ITO.

ISSN:0003-6951    

DOI:10.1063/1.94876

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Nitridization of GaAs surfaces by exposure to a nitrogen or nitrogen‐hydrogen plasma is known to form a surface coating rich in GaN. We show that pretreatment in a hydrogen plasma at room temperature followed by production of this wider band‐gap material by nitrogen plasma treatment at 500 °C for 5 h reduces the reverse leakage current of Au‐GaAs (ND−NA=5×1017cm−3) Schottky diodes by typically an order of magnitude at 300 K.

ISSN:0003-6951    

DOI:10.1063/1.94877

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

20‐&mgr;m‐wide, 1‐mm‐long, single‐crystal Si films on SiO2have been produced using a cw Ar laser beam split by a birefringent quartz plate. The single‐scan recrystallized region width has been widened by multiple beam splitting. The resultant single‐crystal region obtained by multiple scan from the seed is a 90‐&mgr;m‐wide and 100‐&mgr;m‐long area with rare grain boundaries. This split beam method uses the stable and highly efficient TEM00mode and needs no prepatterned antireflection layers.

ISSN:0003-6951    

DOI:10.1063/1.94878

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report the observation of degenerate four‐wave mixing in GaAs above the band gap, using tunable picosecond pulses in the 1.53–1.61‐eV region. A very fast contribution due to orientational gratings of electron‐hole pairs is isolated with orthogonally polarized beams. This is observed for incident intensities down to 5 MW/cm2, i.e., two orders of magnitude lower than recently reported for germanium. Even at this relatively low power density, higher order effects are important, as evidenced by the power dependence of the conversion efficiency.

ISSN:0003-6951    

DOI:10.1063/1.94879

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The relaxation rate of hot carriers following picosecond photoexcitation in GaAs‐AlGaAs multiple quantum well structures is found to be significantly slower than the corresponding rate for bulk GaAs under high excitations. This is confirmed by a detailed comparison of the hot‐luminescence tails for the two cases using picosecond pulse and cw photoexcitations.

ISSN:0003-6951    

DOI:10.1063/1.94880

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A new method of recording and storing information in hydrogenated amorphous silicon devices is demonstrated. The storage mechanism is based on the formation of electron‐beam‐induced defects that act as recombination centers. In the charge collection mode of a scanning probe instrument (e.g., a scanning electron microscope), areas that experience bombardment appear darker in comparison to the unbombarded regions of the device. This leads to a contrast formation for pattern recognition. Annealing of the device at about 200 °C ‘‘erases’’ the stored information.

ISSN:0003-6951    

DOI:10.1063/1.94881

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Amorphous silicon solar cells deposited on tin oxide coated glass with an amorphous silicon carbide  p+front contact layer were subjected to a reverse potential bias while at elevated temperatures. The bias‐anneal treatment improved measured values of open circuit voltage, fill factor, and overall efficiency. The treatment increases efficiency by as much as 18%. The improvement in cell performance appears to be related to an increase in the  &mgr;&tgr; product and possibly an increase in the ionized dopant concentration of one or both contact layers.

ISSN:0003-6951    

DOI:10.1063/1.94882

出版商:AIP    

年代:1984

数据来源: AIP