Publications

Bulk GaN and AlGaNGaN heterostructure drift velocity measurements and comparison to theoretical models

Barker, J.M.; Ferry, D.K.; Koleske, Daniel K.; Shul, Randy J.

The room-temperature velocity-field characteristics for n -type gallium nitride and AlGaNGaN heterostructures, grown epitaxially on sapphire, were determined experimentally. A pulsed voltage input and four-point measurements were used on special geometry samples to determine the electron drift velocity as a function of applied electric field in the basal plane. These measurements show apparent saturation velocities near 2.5× 107 cms at 180 kVcm for the n -type gallium nitride and 3.1× 107 cms at 140 kVcm for the AlGaNGaN heterostructures. A comparison of these studies shows that the experimental velocities are close to previously published simulations based upon Monte Carlo techniques. © 2005 American Institute of Physics.