摘要:

We have measured the electrical impedance of CdTe and Cd0.55Mn0.45Te crystals at temperatures between 82 and 104 K using frequencies between 20 kHz and 2.0 MHz. From the capacitance results we determined that the dielectric constant was only slightly smaller forx=0.45 than forx=0—a result important for the understanding of electromechanical coupling in Cd1−xMnxTe.

ISSN:0021-8979    

DOI:10.1063/1.335502

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The dielectric strength of low‐density polyethylene is measured under high hydrostatic pressure (25–800 bars) at temperature of 20, 45, and 70 °C. First results show that the breakdown fieldEbdecreases at 20 °C and increases with pressure in the range 45–70 °C for short‐time tests. The significant variations ofEbare noted for 70 °C; for example,Eb=3.2 and 4.48 MV/cm forP=25 and 300 bars, respectively.

ISSN:0021-8979    

DOI:10.1063/1.335346

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Annealing effects on electron drift mobility are investigated using time‐of‐flight photocurrent measurements in hydrogenated amorphous silicon. It is found that at room temperature the electron drift mobility and dispersion parameters decrease as annealing temperature is increased, but mobility activation energy remains unchanged by annealing treatments. These results can be explained by the broadening of exponential band tail due to the annealing process.

ISSN:0021-8979    

DOI:10.1063/1.335347

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

New evidence is given for the validity of the number fluctuation model in explaining the 1/fnoise behavior of field‐effect transistors and for the direct proportionality between the oxide trap density and the interface state density at the Fermi level. This evidence is obtained from the determination of the energy distribution of the interface states in small size metal‐nitride‐oxide‐silicon transistors by the modified charge pumping technique.

ISSN:0021-8979    

DOI:10.1063/1.335297

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

A theoretical model of electron temperature and electron mobility as a function of electric field has been formulated for GaAs/AlxGa1−xAs heterostructures. The predicted results from this model agree well with available measurements at low and moderate fields (E>200 V/cm). Furthermore, this model enables us to predict the electron temperature and mobility at high fields which are crucial to the understanding of the potential performance of GaAs/AlxGa1−xAs modulation‐doped field effect transistor and other novel heterostructures.

ISSN:0021-8979    

DOI:10.1063/1.335298

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The first experimental Raman and photoluminescence spectra are presented for the metastable alloy GaAs1−xSbxgrown by organometallic vapor phase epitaxy throughout its miscibility gap extending fromx=0.2 tox=0.75. The phonon peak halfwidths are found to broaden by nearly a factor of 2 over halfwidths found in the binary compounds GaAs and GaSb. Phonon line shapes become more asymmetric in the miscibility gap as the selection rules break down; in addition, a second peak appears for samples grown near the center of the miscibility gap. Line shapes are analyzed and the phonon coherence length is found to be reduced from several hundred angstroms in GaAs to approximately 60 A˚ in samples grown in the miscibility gap. The compositional dependence of the room‐temperature band‐gap energy has been found to closely follow earlier predictions.

ISSN:0021-8979    

DOI:10.1063/1.335299

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

We calculate the contributions of pure collision and phonon‐assisted Auger processes within the framework of the Kane model to the nonradiative lifetime ofp‐doped GaAs. Our approach employs refined expressions for the wavefunction overlap integrals. Further, in contrast to previous treatments, our theory correctly describes the temperature dependence of the optical phonon‐assisted Auger processes. Our values for the Auger lifetimes are in good agreement with experimental results.

ISSN:0021-8979    

DOI:10.1063/1.335300

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

In Se–Tl, Se–Cd, Se–Au, and Se–Te contacts prepared by evaporation on a crystallized selenium layer, Schottky barrier heights were measured from junction capacitance. These were found to decrease systematically with the work function of the contacting metal. From this variation, the density of interface states was estimated to be about 1014cm−2eV−1, assuming an interfacial layer thickness of 10 A˚. The neutral level of the states was estimated to lie close to the valence band edge.

ISSN:0021-8979    

DOI:10.1063/1.335301

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Low‐temperature (∼4 K) photoluminescence has been studied on as‐grown and thermally annealed Si‐doped GaAs grown by molecular beam epitaxy. The peak intensities of the defect‐related emissions, due to the defect‐induced bound exciton (d,X) and the defect complex (d) are decreased by thermal annealing. On the other hand, Hall measurements show that free carrier concentrations are decreased only slightly by thermal annealing.

ISSN:0021-8979    

DOI:10.1063/1.335302

出版商:AIP    

年代:1985

数据来源: AIP