The confined optical phonons of the AlN/GaN quantum well system are describ
ed for an extended version of a continuum theory. The need for the extensio
n is because the reststrahl bands of the two materials overlap and hence a
dispersive mode from one material can propagate in the other, weakening the
confinement. There is also a problem as to which mechanical boundary condi
tions should be used in this case. We compare total electron-phonon scatter
ing rates in a quantum well structure for different mechanical boundary con
ditions and show that, because all of the phonons modes are included, the r
esults are very similar. (C) 1999 Elsevier Science B.V. All rights reserved
.