摘要:

We report on room‐temperature measurements of electron and hole mobilities perpendicularly to the layers of a GaAs/AlGaAs superlattice inserted in an‐i‐nphotoconductor as the intrinsic region. The dynamical behavior of the structure is described by means of a numerical simulation which solves the classical drift‐diffusion transport equations. We discuss the electron and hole mobilities, &mgr;n=120 cm2/(V s) and &mgr;p=12.5 cm2/(V s) respectively, by referring to the two distinct mechanisms of Bloch and hopping conduction, as well as to the peculiar electronic properties of the superlattices.

ISSN:0003-6951    

DOI:10.1063/1.98576

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Data are presented on stripe‐geometry gain‐guided AlxGa1−xAs‐GaAs quantum well heterostructure lasers fabricated via masked (SiO2) hydrogen compensation (‘‘hydrogenation’’) of the Mg and Se dopants in the multiple layer heterostructure. Continuous room‐temperature laser operation is achieved with a threshold current of 24 mA and 24 mW total output at 50 mA. Near‐field emission patterns show strong current confinement in the stripe‐active region, and significant hydrogenation ‘‘undercutting’’ of the oxide mask.

ISSN:0003-6951    

DOI:10.1063/1.98577

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The natural valence‐band offset (NVBO) between semiconductors in a common anion alloy system can be determined through photoemission core level measurements. In this work, we tested this method in the InxGa1−xAs system. The NVBO between GaAs and InAs is measured to be 0.11±0.05 eV. This result is in approximate agreement with the experimental value of 0.17±0.07 eV determined by x‐ray photoemission spectroscopy measurements.

ISSN:0003-6951    

DOI:10.1063/1.98578

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The silicon doping of GaAs grown by metalorganic chemical vapor deposition using a silane source has been investigated. The amphoteric property of the Si dopant is demonstrated for the first time. It is found that the doping characteristics are strongly temperature dependent. At the growth temperature higher than 600 °C and the arsine to trimethylgallium mole ratio (AsH3/TMG) around 217, the conduction isntype and the carrier concentration increases as the temperature increases. On the other hand, when the growth temperature is lower than 600 °C, the carrier concentration increases as the temperature decreases and the conduction becomesptype at 400–450 °C. In addition, when the AsH3/TMG mole ratio is below 50, the Si‐doped GaAs layers also becomeptype. The GaAs light‐emitting diode is thus successfully fabricated using a single silicon dopant.

ISSN:0003-6951    

DOI:10.1063/1.98579

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

High‐quality InAlAs with excellent photoluminescence and low electron concentrations has been grown by organometallic vapor phase epitaxy (OMVPE). For InAlAs lattice matched to InP, electron concentrations as low as 7×1015cm−3and mobilities as high as 4472 cm2/V s at 300 K have been achieved. These values are comparable to results measured on material grown by liquid phase epitaxy and molecular beam epitaxy and exceed results for previously published OMVPE grown material. The variation of the structural, optical, and electrical properties of the InAlAs with lattice mismatch is reported.

ISSN:0003-6951    

DOI:10.1063/1.98580

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The ferromagnetic susceptibility of a magnetoelastic amorphous metal ribbon is determined from the coupled equations of motion for the magnetization and strain modes. This analysis is used to calculate the dynamic sensitivity and field equivalent noise floor of a metallic glass low‐frequency magnetometer. Two principal noise sources are considered: the thermally induced magnetization fluctuations and the Johnson noise of the pick‐up coil. The magnetometer exhibits a calculated minimum detectable field of ∼0.1 pT/(Hz)1/2for room temperature operation at a resonance frequency of 22 kHz and 103turn pick‐up coil having a 200‐&OHgr; resistance. The fundamental material limit is estimated to be ∼5 fT/(Hz)1/2.

ISSN:0003-6951    

DOI:10.1063/1.98581

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Interface positive charge induced in thin oxides (582 A˚ thick) of metal‐oxide‐silicon devices by Fowler–Nordheim injection and x‐ray irradiation was evaluated based on measurements of room‐temperature annealing characteristics. Results showed that in the low‐dose regime, the dose dependence of the density and distribution of the positive charge was different for the two forms of stress. However, at higher doses, the positive charge density produced by both methods increased monotonically while its spatial extent decreased and became more localized at the interface. These latter results are attributed to a buildup of negative charge in the oxide that neutralizes the positive charge furthest from the interface, whereas the differences at low dose are due either to the different character of the positive charge generated by the two techniques or to the much smaller electron density present during irradiation than injection.

ISSN:0003-6951    

DOI:10.1063/1.98582

出版商:AIP    

年代:1987

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.98584

出版商:AIP    

年代:1987

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.98585

出版商:AIP    

年代:1987

数据来源: AIP