摘要:

An improved theoretical investigation into the nonequilibrium characteristics displayed by a metal-insulator-semiconductor device when subjected to a linear voltage ramp is presented. The model takes into account the finite bulk-trap generation width for those traps initially above the Fermi-level. The resultingI/Vcharacteristics show considerable deviation from those where it assumed that the bulk traps intially above the Fermi-level either generate as a whole or do not generate at all.

DOI:10.1049/ip-i-1.1982.0026

出版商:IEE    

年代:1982

数据来源: IET

摘要:

The paper develops a simple theory to account for the magnetoresistance influence on Van der Pauw-type experiments (i.e. resistivity and Hall coefficient RHmeasurements in arbitrarily shaped samples). In particular, it is proved that the voltage developed between two nonsuccessive contacts includes not only the usual Hall term (involving the magnetic field and RH) but also an additional term proportional to the magnetoresistance coefficient. This term is especially important under high magnetic fields and in anisotropic or ambipolar semiconductors; if ignored, it will be responsible for misleading interpretations of the Hall coefficient behaviour. Moreover, the influence of contact dimensions is shown to result mainly in an erroneous term, proportional to the Hall voltage. In this new light averaging techniques, suitable for more accurate measurements, are proposed. The experimental results fully support the theoretical derivations. As an application, a powerful method for the characterisation of ambipolar semiconductor slabs with arbitrary geometry is presented.

DOI:10.1049/ip-i-1.1982.0027

出版商:IEE    

年代:1982

数据来源: IET

摘要:

Monte Carlo simulation of electron transport in a GaAs diode, of n+−i(n)−n+structure, with a 0.25 μm− or 0.5 μm−long active layer is described. The anode voltage ranges from 0.25 V to 1.0 V. The distributions of electron energies and electron velocities, and the profiles of the electron density, electric field, potential, and average electron velocity are computed. Based on these data, the near ballistic nature of the electron transport in the 0.25/um−long diode and the importance of the back-scattering of electrons from the anode n+−layer are discussed. Also, the effects of the lattice temperature and doping on the length of the active layer, and a comparison with a Si diode are discussed.

DOI:10.1049/ip-i-1.1982.0029

出版商:IEE    

年代:1982

数据来源: IET

摘要:

The efficiency of Schottky-barrier photodiodes can be much improved by the inclusion of a monolayer of a suitable amphiphilic substance. Such layers have hitherto been formed by the Langmuir-Blodgett technique. In the paper we describe results obtained using monolayers adsorbed from an alkane solvent, and compare them with results obtained using the Langmuir-Blodgett method. It is shown that adsorbed layers lead to superior layers, and also make it possible to use perfluorinated carboxylic acids which have apKatoo low to be applied by the Langmuir-Blodgett technique.

DOI:10.1049/ip-i-1.1982.0030

出版商:IEE    

年代:1982

数据来源: IET

摘要:

Bistable operation is examined in the paper for DH semiconductor lasers employing inhomogeneous excitation. Steady-state rate equations are analysed in terms of typical parameters for contemporary stripe-geometry lasers, and it is shown that the I/L curves demonstrate bistability. Characteristics for optical bistable-switching operations effected by trigger current pulses are also numerically analysed through the use of nonlinear rate equations. Bistable operation has been achieved experimentally with InGaAsP/InP DH lasers through a newly designed periodic excitation stripe geometry. Bistability was observed within a current range less than 10° of the threshold current. The range was seen to strongly depend on the stripe geometry anddevice temperature, which are controllable. Switching between the two stable states was accomplished by application of an electrical pulse. Switching time was about 1 ns.

DOI:10.1049/ip-i-1.1982.0031

出版商:IEE    

年代:1982

数据来源: IET

摘要:

Experimental results are reported on the effect of electron-dominated and hole-dominated photocurrent on silicon flat-profile X-band impatt oscillators. Electron-dominated photocurrent noise is shown to degrade oscillator characteristics more than hole-dominated photocurrent noise, and this is attributed to the higher electron ionisation coefficient in silicon. The nominal photocurrent level is shown to reduce FM noise at large signal levels, as previously predicted. This noise reduction is only observed with hole-dominated photocurrent, owing to the longer intrinsic response time. The experimental results indicate that fluctuations in effective leakage current levels of 0.1% can significantly increase the oscillator noise level

DOI:10.1049/ip-i-1.1982.0032

出版商:IEE    

年代:1982

数据来源: IET