摘要:

The formation of indium‐donor pairs (donors: P, As, Sb) in silicon is identified by perturbed angular correlation spectroscopy. After the electron capture decay of the111In probe atoms to111Cd, the electric field gradient (EFG) is measured at the corresponding cadmium‐donor pairs. For all three complexes a similar temperature dependence of the EFG is observed which can be explained quantitatively by a model based on the charge state of the cadmium‐donor acceptors. The corresponding energy levels are given.

ISSN:0003-6951    

DOI:10.1063/1.102265

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A theory of time jitter in semiconductor lasers initially biased just below threshold is developed. Simulations of the buildup of emitted optical pulses in lasers starting from below or above threshold are also presented which, for initial biasing up to threshold, are in good agreement with the theory. In particular, we show that time jitter does not vary for biasing currents up to about 0.95 of the threshold value, while it suffers a small increase at threshold and a steep decrease for higher biasing currents.

ISSN:0003-6951    

DOI:10.1063/1.101800

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Continuous and pulsed photoluminescence experiments in GaSb/AlSb multiple quantum wells have been performed before and after exposure to hydrogen. An appreciable increase in the emission efficiency has been observed for H ion doses as low as 1013/cm2. Since the results cannot be accounted for in terms of the plain passivation of nonradiative centers, the effect is ascribed mostly to a change in the mechanism of carrier relaxation within the lower end of the bound‐state distribution.

ISSN:0003-6951    

DOI:10.1063/1.101802

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

GaAs metal‐semiconductor field‐effect transistors (MESFETs) with extremely low resistance nonalloyed ohmic contacts have been demonstrated. The contact structure consists of ann+‐InAs/GaAs strained‐layer superlattice and an InAs cap layer. Contact resistances as low as 0.036 &OHgr; mm have been measured. These results represent the smallest figures reported to date for GaAs field‐effect transistors. Nonalloyed MESFETs with 1 &mgr;m gate lengths had transconductances of about 210 mS/mm.

ISSN:0003-6951    

DOI:10.1063/1.101803

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We describe a simple, new method for deducing surface alloy composition during ternary III/V molecular beam epitaxy. The method is based on on‐line reflection mass spectrometry of the group V flux ‘‘reflected’’ from the surface during momentary terminations of individual group III fluxes.

ISSN:0003-6951    

DOI:10.1063/1.101804

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Ballistic‐electron emission microscopy (BEEM) has been used to investigate the origin of defects at the Au/GaAs(100) Schottky barrier interface. In addition, molecular beam epitaxy (MBE) andinsitufabrication methods have been employed to control Schottky barrier interface properties. BEEM characterization combined with MBE methods has enabled the development of a near‐ideal Schottky barrier interface with drastically reduced defect density.

ISSN:0003-6951    

DOI:10.1063/1.101778

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The microstructure of hydrogenated amorphous silicon‐carbon alloys has been analyzed by small‐angle x‐ray scattering, infrared absorption, and density measurements. Decreasing density with C incorporation is due to microvoids about 0.6 nm in average radius, which are either approximately spherical in shape or randomly oriented nonspheres. The microvoid number density increases from about 5×1019/cm3fora‐Si:H to about 4×1020/cm3fora‐Si0.7C0.3:H. The CH3species probably causes the enhanced microvoid formation in these alloys. A large fraction of the microvoid surfaces is not hydrogenated.

ISSN:0003-6951    

DOI:10.1063/1.101779

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The strain configuration in CdTe/ZnTe strained‐layer superlattices has been measured by Raman scattering near resonance. The ZnTe‐like longitudinal optical phonon energy in the superlattice is significantly shifted from the bulk value to lower energies and the shift increases with increasing superlattice CdTe fraction. The observed shifts agree with calculations of strain shifts based on a free‐standing strain distribution.

ISSN:0003-6951    

DOI:10.1063/1.101781

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We have fabricated the first InAs‐channel field‐effect transistor, which shows a transconductance of 180 mS/mm at 1 V drain‐source bias (77 K). An improved buffer layer could significantly improve the device performance. In addition, we propose a new broken‐gap heterojunction field‐effect transistor based on these materials that could provide an order of magnitude higher transconductance compared to existing device configurations based on AlGaAs/GaAs.

ISSN:0003-6951    

DOI:10.1063/1.101761

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We describe a large lateral photovoltage that develops in AlGaAs/GaAs modulation‐doped structures in response to excitation by spot illumination. The effect is observed in wafers where the equilibrium inversion channel electron density is negligibly small. This effect is sensitive to the position of the illuminated spot. The dependence of the induced photovoltage on the power and the spectral composition of the excitation as well as its temperature dependence has been carefully studied. A resistive two‐channel transmission line model has been developed to explain the experimental results.

ISSN:0003-6951    

DOI:10.1063/1.101762

出版商:AIP    

年代:1989

数据来源: AIP