An extended drift-diffusion model of semi-insulating n-GaAs Schottky-barrier diodes

Abstract

We present an extended drift-diffusion modelling to study electron transport in semi-insulating n-GaAs Schottky-barrier diodes. The model accounts for hot-carrier dynamics and associated kinetics of electrical active traps. A field-enhanced capture cross-section of the two deepest electron traps, attributed to EL2 and EL3 centres, is found to determine the main characteristics of this device. A detailed description of the profile of the electric field, free charge and other related quantities is provided. The modelling compares well with available experimental results and confirms the suitability of this device to be used as a detector for nuclear radiation.

Study on instability phenomena in CdTe diode-like detectors

“…In other terms, when high concentrations of deep-levels are present, Poisson equation is not sufficient to describe the electric properties and coupling with drift diffusion equation has to be taken into account [18].…”

Slow domains in semi-insulating GaAs

“…Recent experiments [3][4][5][6][7][8][9] that use the electro-optic Pockels effect in order to measure the local electric fields in the sample have opened up the way towards a more detailed quantitative understanding of the domains and the trapping process in SI GaAs. There is a considerable interest in the properties of the EL2 defect because SI GaAs has an increasing relevance, e.g., as a particle detector [10][11][12][13] and for optical data storage. 14 The reader may well wonder why the transport properties of SI GaAs should be of any particular interest.…”

Monte Carlo simulation of the induced signal in semi-insulating GaAs detectors

“…[1][2][3] The presence of deep traps with field-enhanced capture has been found 2,4 to promote an active region with almost constant field ͑10-20 kV/cm͒, which widens at increasing applied voltages. Its main advantages are: high Z number ͑i.e., high stopping power͒, high carrier mobility ͑i.e., fast collecting times͒, and high intrinsic resistivity ͑i.e., low leakage currents͒.…”

“…3 From the above ''dark'' condition, we consider the generation of an excess electric charge ͑electrons and/or holes͒ at a given point inside the SBD and simulate its full dynamics ͑i.e., motion and trapping/detrapping processes͒. To this purpose, we start from a drift and diffusion modeling of the dark characteristics of a SBD.…”