Abstract

A strong piezoelectric polarization exists in strained III-V heterostructures with non-(100) orientation.¹ This polarization normally splits up in a component parallel and a component perpendicular to the interfaces. In ideal quantum wells without any lateral structuring only the polarization component perpendicular to the interfaces creates polarization charges and hence electric fields. Research activities up to now have focussed exclusively on these vertical electric fields. The inactivity of the polarization component parallel to the interfaces, however, can be lifted by a lateral patterning of the quantum well. Then the parallel component also generates piezoelectric charges and thus introduces lateral piezoelectric fields. These lateral fields can be significantly stronger than vertical fields. The separation of negative and positive charges can thus be much larger than in the case of vertical fields. Furthermore, lateral fields can be created by much smaller total amounts of piezoelectric charge than vertical fields.

© 1994 IEEE