Comparison of high field electron transport in GaN and GaAs

An ensemble Monte Carlo simulation is used to compare high field electron transport in bulk GaN and GaAs. In particular, velocity overshoot and electron transit times are examined. In GaN, we find the steady state velocity of the electrons is the most important factor determining transit time over distances longer than 0.2 μm. Over shorter distances velocity overshoot effects in GaN at high fields are comparable to those in GaAs. We estimate the minimum transit time across a 1 μm GaN sample to be about 3.0 ps. Similar calculations for GaAs yield 5.4 ps.