Session K23 - QHE Theory and Special Topics.
ORAL session, Tuesday afternoon, March 04
Room 15, Austin Convention Center
Collective impact ionization has been developed to explain lock-on, an optically-triggered electrical breakdown that occurs in GaAs photoconductive semiconductor switches (PCSS's). The basic principle of collective impact ionization is that, at high carrier density, carrier-carrier interactions increase the impact ionization probability by increasing the number of carriers with energies above the impact ionization threshold. In this presentation, we will discuss a rate equation approach that leads to new insights about electrical breakdown in insulating materials. In this approach, the competition between carrier generation and recombination leads to steady state solutions that govern whether breakdown does or does not occur. This approach leads to definitions for not only the lock-on field but also the breakdown field. Results obtained for GaAs, InP, and Si using a carrier distribution function calculated by both a Maxwellian approximation and an ensemble Monte Carlo method will be discussed.