摘要:

A theoretical method for calculating the variation of optical transition energyEg,optin semiconductors with heavyndoping is presented. The calculations based on the Moss–Burstein shift and band‐gap shrinkage take into account both exchange and Coulomb interactions, the latter being calculated for nonparabolic bands. A comparison with the experimental values ofEg,optfor heavilyn‐doped GaAs and InP shows good agreement over wide ranges of temperature and doping and can satisfactorily explain photoluminescent emission at energies up to 1.65 eV in GaAs (1.8 °K) and 1.91 eV in InP (300 °K).

ISSN:0003-6951    

DOI:10.1063/1.93882

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Biased metal‐insulator‐semiconductor (MIS) capacitors are known to exhibit a flatband voltage shift which is logarithmic in time. This phenomenon has been attributed to charge exchange between the semiconductor surface and a set of insulator traps distributed either in energy or in depth. It is shown that logarithmic time dependence is also an attribute of a simple capture model which incorporates the relaxation of the semiconductor surface potential which occurs as the density of total trapped charge changes. The predictions of this model are compared with experimental results obtained from a biased MIS structure comprising 600 A˚ of native oxide onn‐type Hg0.70Cd0.30Te.

ISSN:0003-6951    

DOI:10.1063/1.93883

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A standard cleaning procedure for GaAs (100) molecular beam epitaxial (MBE) substrates is a chemical treatment with a solution of H2SO4/H2O2/H2O, followed byinsituheating prior to MBE growth. X‐ray photoelectron spectroscopic (XPS) studies of the surface following the chemical treatment show that the oxidized As is primarily As+5. Upon heating to low temperatures (<350 °C) the As+5oxidizes the substrate to form Ga2O3and elemental As (As0), and the As+5is reduced to As+3in the process. At higher temperatures (500 °C), the As+3and As0desorb, while the Ga+3begins desorbing at ∼600 °C.

ISSN:0003-6951    

DOI:10.1063/1.93884

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

We have observed photon‐assisted tunneling effects at 246 and 604 GHz in small‐area superconductor‐insulator‐superconductor (SIS) and superconductor‐insulator‐normal metal (SIN) superconducting junctions. We find excellent agreement with the Tien–Gordon theory, and infer that the responsivity of SIN junctions approaches the quantum limit at low temperatures for photon energies less than 2&Dgr;.

ISSN:0003-6951    

DOI:10.1063/1.93885

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Numerical and analog solutions to a differential equation describing an rf‐driven Josephson junction were obtained; variations of the quantum phase difference across the junction and its time derivative provide clear examples for the existence of intermittency in this nonlinear system. A critical exponent is determined in agreement with theoretical predictions.

ISSN:0003-6951    

DOI:10.1063/1.93886

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

This letter reports that the magnetoresistance ratio &Dgr; &rgr;/&rgr; increases and the coercive forceHcreduces in vacuum‐evaporated permalloy films by implanting H+2ions. The increase in &Dgr; &rgr;/&rgr; is due to a decrease in the resistivity &rgr;, and the magnetoresistance coefficient &Dgr; &rgr; remains almost unchanged. By implanting H+2ions &rgr; becomes nearly equal to that of the permalloy bulk in the film thickness range of more than 3000 A˚. The coercive forceHcremarkably decreases to the small value in the thinner films range. The grain size of ion‐implanted films is about the same as that of non‐ion‐implanted films. This shows that the decrease in &rgr; is not due to the grain growth mechanism as in annealed films but may be due to some mechanism of the grain boundary change caused by implanted ions. The mechanism of decrease in &rgr; andHcremains to be clarified.

ISSN:0003-6951    

DOI:10.1063/1.93887

出版商:AIP    

年代:1983

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.94112

出版商:AIP    

年代:1983

数据来源: AIP