Predicted maximum mobility in bulk GaN

A 300 K bulk (three-dimensional) mobility of 1245 cm(2)/V s has been measur ed in free-standing GaN. Temperature-dependent Hall-effect data on this par ticular sample are fitted to obtain unknown lattice-scattering parameters, as well as shallow donor (N-D) and acceptor (N-A) concentrations, which are N-D=6.7x10(15) and N-A=1.7x10(15) cm(-3). Realistic values of the maximum mobility attainable in bulk GaN are then obtained by assuming two-orders-of -magnitude lower values of N-D and N-A, leading to a maximum 300 K mobility of 1350 cm(2)/V s, and a maximum 77 K mobility of 19 200 cm(2)/V s. (C) 20 01 American Institute of Physics.