Theoretical Studies of High Energy Transport of Electrons and Holes in Gallium Arsenide, Indium Phosphide, Indium Arsenide, and Gallium Antimonide.

摘要

This thesis studies the high field behavior of both electrons and holes using a Monte Carlo calculation including a complete band structure. The Monte Carlo method can be applied to both steady state and transient problems. The calculated steady state high field properties include the drift velocity and the impact ionization rate. It is determined theoretically that either Gallium Arsenide or Indium Phosphide the electron and hole steady state drift velocities are roughly the same. The calculated carrier drift velocities in InP are larger than in GaAs. The impact ionization rate of both electrons and holes is calculated including quantum effects. It is found that the electron impact ionization rate is larger in GaAs than in InP because of the higher ionization threshold energy and greater density of states in InP. The electron ionization rate is greater than the hole ionization rate in GaAs because the electrons can drift to energies at or above the threshold energy, which is the same for both carriers, easier than the holes can. Among the transient transport problems examined is velocity overshoot of both electrons and holes in GaAs, InP, and InAs. It is determined that there exists a narrow range of parameters such as the applied electric field, the initial condition (launching energy and momentum), the boundary condition at the collecting contact, and the semiconductor dimensions that result in significant velocity overshoot. The calculations show that the overshoot is greater in InP than in GaAs. This is because the valley separation energies are larger in InP so the electrons are more easily confined to the low effective mass gamma valley.