Energy model for optically controlled MESFETs

Abstract

An energy‐based transport model for the analysis of illuminated microwave active devices is presented. The model is based on the Boltzmann's transport equation, with optical carrier generation and carrier recombination accounted for. The simulation results are compared with the conventional local‐field mobility models based on drift‐diffusion formulations. It is shown that the drift‐diffusion models lose their applicability in submicrometer gate‐length devices. The presented time‐domain model has a great potential in the analysis of microwave devices under ac and pulsed illumination conditions. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 26: 48–52, 2000.

Optoelectronic conversion of short pulses in sub-micrometer GaAs active devices

“…The active device model is based on the moments of the BTE obtained by integration over momentum space. The integration results in a strongly-coupled highly-nonlinear set of partial differential equations called the conservation equations (Alsunaidi 2000;Blotekjaer 1970). These equations provide a time-dependent self-consistent solution for carrier density, carrier energy and carrier momentum and are given by…”

“…These efforts fall in two main categories: analytical and equivalent circuit models. A recent review of these GaAs models can be found in Alsunaidi (2000) and Murty and Jit (2006). Although they provide representations of the device global operating conditions, analytical models are very well known for their simplifying assumptions.…”

“…Also, the treatment of short-optical-pulse effects into these models is not straightforward. An alternative technique is based on physical models, where the fundamental equations describing the microscopic carrier transport phenomena are solved numerically (Alsunaidi 2000). With this technique, all physical considerations are accommodated and, usually, the same simulation algorithm is used for any geometrical, operational or input conditions.…”

“…The Boltzmann's transport equation (BTE), on the other hand, provides time-dependent representations of the carrier density, carrier energy and carrier momentum, and takes care of sub-picosecond non-equilibrium transport. A numerical simulation algorithm based on the finite-difference time-domain (FDTD) method that consistently solves the BTE under illumination conditions has been developed and rigorously validated and tested in several publications (Alsunaidi 2000;Alsunaidi et al 1997Alsunaidi et al , 2001.…”