Steady state and transient electron transport properties of bulk dilute GaNxAs1−x

Abstract

Two valley ensemble Monte Carlo simulations have been performed to investigate the electronic transport properties of bulk GaNxAs1−x alloys where the nitrogen concentration x ≤ 0.02 (2%). We have investigated these properties using two separate approaches, 1) through simulation of GaAs using the standard Kane model with the addition of isolated and pair state nitrogen scattering mechanisms and 2) approximating the lower “mixed state” band that arises from the use of band-anticrossing model with an analytic function that implements the inflection point (for concentrations >1%). From the steady-state properties, we find that the nitrogen scattering model produces a better fit with other results, both theoretical and experimental. We also comment on the transient properties of GaNxAs1−x, noting that the velocity overshoot peaks are of a much lower velocity than is found in GaAs at comparable field strengths, and through the use of model 2, that negative effective mass states have a significant role in the transient behavior. We find that the system takes much longer to reach equilibrium when compared to bulk GaAs in both models, and through the use of model 2, there is a significant population of negative effective mass states when the system is subjected to higher fields.