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Goals Simulations: Breakdown & “lock-on” in photoconductive semiconductor switches (PCSS’s) Understand the behavior of GaAs, Si, & InP PCSS’s at 4 to 30 kV/cm fields. Approach Collective impact ionization theory: Effect of carrier-carrier scattering on impact ionization.
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Goals Simulations: Breakdown & “lock-on” in photoconductive semiconductor switches (PCSS’s) Understand the behavior of GaAs, Si, & InP PCSS’s at 4 to 30 kV/cm fields. Approach Collective impact ionization theory: Effect of carrier-carrier scattering on impact ionization. Simulations: Ensemble Monte Carlo & Maxwellian distribution Results:Generalized Breakdown Breakdown & “lock-on”: Two aspects of the same phenomenon Steady state electric field (F) & carrier density dependence (n) of breakdown Personnel:Ken Kambour, PhD student/Sandia visitor; H.P. Hjalmarson (Sandia), C.W. Myles (TTU) Semiconductor Switch SimulationsTexas Tech U. & Sandia National Labs Fig. 1.Photoconductive switch(PCSS) with optical illumination and current filaments Fig. 2.Generalized Breakdown (Model Material): n vs. F: Minimum F on curve = Breakdown field without (red) & with (blue) carrier-carrier (CC) scattering. CC-scattering lowers the breakdown field. “Lock-on” = Breakdown with CC scattering.