Piezoelectric effect on the optical phonon modes of strained cubic semiconductors: Case of CdTe quantum wells

We report on Raman experiments of uniaxially stressed bulk CdTe and strained CdTe/CdZn(Mn)Te [001] and [111] quantum wells, which allowed us to determine the strain and piezoelectric field phonon deformation potentials (PDP’s) for the LO phonons in CdTe. Several PDP’s for the CdTe TO phonons have been extracted as well. We demonstrate that the piezoelectric effect on the phonon frequencies brings in a non-negligible correction, which should be taken into account in all strain-characterization Raman experiments on piezoelectric nanostructures. Examples on the piezoelectric-field induced phonon shifts are given for TO and LO phonons of low-symmetry grown ([111], [211], [311]) strained quantum wells of CdTe.