首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 93 毫秒
1.
Partial Auger recombination of the (D0, X) bound-exciton in n-GaAs at 4.2 K during an impact ionization avalanche under an applied pulse voltage has been investigated. The bright photoluminescence (PL)-pattern observed by applying the pulse voltage, characterizes well the formation of a current density filament. The observation of the bright PL spectra inside the current density filament gives a quite new result concerning the partial Auger recombination process of the (D0, X) complex, leaving the neutral donor in the excited states.  相似文献   

2.
We present a study of the photoresponse spectrum of heterojunctions ofn-GaAs with amorphous As2S3 films with various thicknesses of the glassy chalcogenide semiconducting film. We obtain an expression to calculate the fraction of the light absorbed in the glassy semiconductor, the fraction of the light absorbed in GaAs, taking into account the multiple reflections at the interfaces in the structure under study, and also their ratio. We present an analysis of the absorption of light in the structure. The calculated results show good agreement with experiment. University of Kaliningrad, Kaliningrad. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 42, No. 1, pp. 3–8, January, 1999.  相似文献   

3.
Spin-wave structures with magnetic-field-driven current-voltage characteristics at room temperature were produced using a spintronic europium-monoxide-based thin-film emitter and a single-crystal n-GaAs semiconductor collector. This manifests practical implementation of the spin current transport and creation of a high-temperature spin transistor with the magnetic semiconductor/nonmagnetic semiconductor contact.  相似文献   

4.
A computer simulation study of the capacitance of a surface space charge layer in undoped n-GaAs grown by metalorganic vapour phase epitaxy is presented. The effect of the deep donor level EL2 on the surface capacitance of epilayers with an ideal free surface is estimated. In order to approach the as-grown layer surface the model used is extended considering MIS and Schottky-barrier structures and their voltage-capacitance curves are analysed. The theoretical C-V dependences are compared with experimental C-V curves of a real structure including N+-GaAs substrate, undoped n-GaAs epitaxial layer containing EL2 levels and thin native oxide. Conditions are determined at which the EL2 levels as well as the native oxide film may influence the capacitance characteristics.  相似文献   

5.
Far-infrared photoconductivity ofn-GaAs epitaxial layers showing impact ionization breakdown has been investigated by molecular lasers at photon energies below the 1s-2p shallow donor transition energy. Negative photoconductivity was observed if a magnetic field was applied to the crystals and if impact ionization of donors by the electric bias field was the dominant electron excitation mechanism. The experimental results are qualitatively explained on the basis of the generation-recombination kinetics of electrons bound to donors. Negative photoconductivity is attributed to optically induced free to bound transitions of electrons from theN=0 Landau band to donor levels shifted by the magnetic field above the low energy edge of the conduction band.  相似文献   

6.
As an effort to improve the conversion efficiency of InGaP/InGaAs/Ge triple junction solar cells, we investigated the effect of AlGaAs barrier layer on the cell performance under concentrated light condition. Three different solar cells having upper tunnel junctions (TJs) as n++-GaAs/p++-AlGaAs layers, n++-GaAs/p++-GaAs layers and n++-GaAs/p++-GaAs/p++-AlGaAs layers were prepared. Under concentrated light condition, open-circuit voltage (VOC), fill factor (FF) and conversion efficiencies were higher for the sample with an AlGaAs barrier layer than the samples without an AlGaAs barrier layer. For the sample with an AlGaAs barrier layer, external quantum efficiency was higher than other two samples. Most of all, the sample with a TJ as n++-GaAs/p++-GaAs layers showed a very poor electrical performance, which was associated with an imperfect crystalline quality of the InGaP top cell layers.  相似文献   

7.
We propose a method for determining the behavior of the conductivity of high-resistance photosensitive films separated from the substrate by a space charge region. The method is based on measurement of the potential distribution ϕ(r) over the surface of an illuminated film which arises as the photocurrent flows through it. We have studied diode structures made ofn-GaAs, fabricated by doping with deep acceptor impurities which act as fast switches and photodetectors with high sensitivity in the ultraviolet region. The results are compared with literature data for iron-doped GaAs. V. D. Kuznetsova Physicotechnical Institute, Tomsk State University, Siberia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 68–72, April, 1998.  相似文献   

8.
A review is given of the nonlinear response and chaos induced by impact ionization of neutral shallow donors, observed in n-GaAs. Two kinds of the observation are described; (i) firing wave instability, and (ii) periodically driven current filament. For the firing wave instability, several important aspects are discussed including the selective excitation of the current filaments and the deterministic nature of the firing density wave. The nonlinear response of a periodically driven current filament has been investigated by applying a dc+ac bias of the form ofV dc+V ac sin(2f 0 t), wheref 01 MHz. The carrier dynamics and the bifurcation routes to chaos are discussed in terms of the observed phase diagram and the bifurcation map. The deterministic nature of the strange attractors are described in detail in terms of the correlation dimension and the Kolmogorov entropy.  相似文献   

9.
The transient I-V characteristic of an amorphous GaTe3-crystalline n-Si barrier negistor structure under negative differential resistance (NDR) conditions is studied. The basic parameters (cross-section radius, current density, and resistivity) of the current filament region in the amorphous layer of the structure are determined. Results obtained are compared with the associated parameters of the current filament in a C-amorphous GaTe3-C reference barrier-free structure. Under NDR conditions, the conductivity of the filament region in this heterostructure is shown to be governed largely by processes occurring in the crystalline component.  相似文献   

10.
Using local point-contact probes, we observed two types of low-frequency instabilities inn-InSb at 85 K if the samples were exposed to crossed fields. One is a local density instability with threshold frequencies off = 1 20 Mc, the other a more turbulent current instability. The threshold values ofU 0 andB for the onset of these instabilities and the dependence of their amplitudes on the fields have been measured.If a rectangular semiconductor slab is placed in crossed fields, regions of high electric field strength at opposite edges of the contacts are caused by the distortion of the Hall field, giving rise to the generation of electron-hole plasmas by impact ionization. These plasmas are the sources of the observed instabilities. This is especially evident in the case of the local density instability, which originates at the anode high field corner. Several possible reasons for the development of the instabilities are discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号