Non-linear piezoelectric effect in CdTe and CdZnTe
نویسندگان
چکیده
Strained quantum wells (QWs) grown along the polar axis (1 11) in a zincblende semiconductor exhibit a piezoelectric field. This field strongly modifies the energy of excitons confined in QWs. We have extracted, from optical measurements of excitonic transitions, the piezoelectric field value in a large set of QWs: CdTdCdZnTe, CdTeICdMnTe, CdZnTeICdMnTe. By suitably choosing the composition of alloys, we have obtained different values of strains (compressive or extensive) due to the lattice mismatch between QWs and barriers. The non-linear piezoelectric effect appears clearly when plotting the piezoelectric tensor component e 4 versus lattice mismatch. For example el4 increases from 0.07 C/m2 to 0.15 C/m2 wien the lattice mismatch varies from 0.3% to 1.7%.
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