Piezoelectric Scattering in Large-Bandgap Semiconductors and Low-Dimensional Heterostructures

ABSTRACTWe develop a rigorous theory of piezoacoustic phonon limited electron transport in bulk GaN and GaN-based heterostructures. Within the Boltzmann equation approach we derive a new expression for the momentum relaxation rate and show that the Pauli principle restrictions are comparable in importance to a screening effect at temperatures up to 150 K provided that the electron density is large. This is of particular importance for electrons in GaN/AlN-based quantum wells where very high electron densities initiated by the piezoelectric effect have recently been reported. Variations of the piezoacoustic phonon limited electron mobility with the lattice temperature and with the electron density for a zinc-blende and wurtzite GaN are presented.