Piezoelectric Effect in Strained CdTe-Based Heterostructures

Strained III-V or II-VI heterostructures grown along a polar axis incorporate a piezoelectric field which strongly alters their electronic properties. We review some experimental studies of this built-in field, and its consequences, in CdTe-CdMnTe and CdTe-CdZnTe heterostructures. This includes: (i) the measure of the built-in field, with as an example the dependence of the piezoelectric coefficient on bond length; (ii) the description of the exciton formed by an electron and a hole which can be continuously separated in space by the piezoelectric field; (iii) some examples of the extreme sensitivity to any additional electric field.