摘要:

Pump-probe differential transmission measurements examine high-carrier-density phenomena in as-grown and annealed GaAs samples grown at temperatures from 210 to 270 °C. We observe trap saturation and Auger recombination, and accurately model the measurements on annealed samples with a simple two level rate equation, allowing us to extract the trapped-electron lifetimes. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119138

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

An analytical model for the spatial correlations and noise across an abruptn+njunction is presented. The model is able to treat the junction as a whole in strongly inhomogeneous conditions self-consistently, by taking into account both the drift and diffusion contributions to the current. It is shown that within the analytical approach, the voltage noise across the junction can be decomposed into the sample and the contact contributions and the term representing sample-contact cross correlation. It is argued that the proposed analytical method is quite universal and could be effectively applied to different devices, operating under strongly inhomogeneous distributions of the electric field and charge concentration. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119151

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The results of high-frequency mixing experiments performed upon parallel quantum point contacts defined in the two-dimensional electron gas of anAlxGa1−xAs/GaAsheterostructure are presented. The parallel geometry, fabricated using a novel double-resist technology, enables the point-contact device to be impedance matched over a wide frequency range and, in addition, increases the power levels of the mixing signal while simultaneously reducing the parasitic source-drain capacitance. Here, we consider two parallel quantum point-contact devices with 155 and 110 point contacts, respectively; both devices operated successfully at liquid helium and liquid nitrogen temperatures with a minimal conversion loss of 13 dB. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119139

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

It has been demonstrated that the expression for the temperature dependent tunneling current through a triangular potential barrier at metal/polymer interfaces fits experimental data including the deviation from a straight line observed in Fowler–Nordheim plots. The fitting parameters can be used to calculate the potential barrier height at the metal/polymer interface, which is of crucial importance for the control of charge injection in organic light emitting diodes. The tunneling current density expression reproduces the observed dependence of the current with temperature. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119149

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Photoluminescence measurements under different excitation powers and time-resolved photoluminescence experiments were carried out at low temperature on tensile strainedIn0.3Ga0.7Asquantum wells with InGaAs barriers lattice matched to InP. Evidence of a type II recombination is found between carriers confined in the tensile strained layer and in the lattice matched one. This study allows us to propose a precise determination of the light holes band offset in theIn0.3Ga0.7As/In0.53Ga0.47Assystem. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119140

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The application of hydrogenated amorphous silicon Schottky diodes to large-area imaging requires knowledge of the variation in reverse-bias current over long timescales. When the diode is subject to electrical stress, a power-law dependence of reverse current with time is observed. This is followed by a stretched-exponential behavior during the subsequent zero-bias recovery period. Both of these results are attributed to dispersive electron transport in the Schottky diode. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119141

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Short-period superlattice minibands have been studied by ballistic electron luminescence spectroscopy. Using a combination of optical and electrical measurements in a single device, electron transport through an AlGaAs/GaAs superlattice was observed. The optical measurement provided a precise energy scale for calibration of voltages obtained in the electrical experiment. A three terminaln-p-pdevice was used, where the electrons were injected through an emitter-base tunnel barrier into ap-type base, which was separated from thep-doped collector by a superlattice. Luminescence emitted by ballistic electrons recombining in the base was used to measure their kinetic energy. Oscillations in the transistor gain were detected and are due to transport through the superlattice miniband. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119142

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The epitaxial growth of InSbBi ternary alloys by low-pressure metalorganic chemical vapor deposition is reported on. X-ray diffraction spectra showed well resolved peaks of InSbBi and InSb films. Bi incorporation was confirmed by energy dispersive x-ray analysis. Photoresponse spectrum up to 9.3&mgr;m which corresponds to 0.13 eV energy band gap has been measured in a sample with Bi composition of 5.8 at.&percent; at 77 K. Electron mobility at room temperature ranges from 44 100 to 4910 cm2/Vs as Bi composition increases. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119158

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Multiple total internal reflection Fourier transform infrared spectroscopy is used to detect combinational phonon bands ofSiO2at 1645, 1852, and2000 cm−1in thin films produced by plasma enhanced chemical vapor deposition. The isotopic shifts of these bands in films deposited fromSiH4/18O2mixtures proved that combinations ofSiO2phonons give rise to the additional absorption peaks. Detection of these combinative phonon bands enables one to use Si multiple total internal reflection crystals for studying Si–O phonon absorptions inSiO2films on Si. In principle, films as thin as a few angstroms can be detected using the infrared absorption by the combinational bands. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118424

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The formation of a nanometer-size oxide pattern on silicon using a scanning probe microscope (SPM) has been widely reported in the literature. No analytical model has been proposed, however, to explain the variation of the oxide height with both polarization and speed of the SPM tip. In this letter, we explain quantitatively the variation of the oxide height with the polarization and the speed of the tip with a model based on field induced oxidation. Data analysis also allows us to estimate the thermal activation energy of the oxidation process,(∼0.15 eV).This low value is compared with activation energies measured for thermal and plasma oxidation of silicon. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118425

出版商:AIP    

年代:1997

数据来源: AIP