Strain and piezoelectric potential effects on optical properties in CdSe/CdS core/shell quantum dots

Abstract

Strain and piezoelectric potential effects on optical properties in CdSe/CdS core/shell quantum dots (QDs) were investigated theoretically using an eight-band strain-dependent k·p Hamiltonian. The strain effect on the shift of the subband energies is found to be larger than the piezoelectric field effect. As a result, interband transition energies are blueshifted with the inclusion of strain and piezoelectric field effects. We know that the theoretical interband transition energy shows a reasonable agreement with the experimental result. The absolute value of the hydrostatic strain in the QD increases with decreasing QD size, whereas that in the barrier decreases with decreasing QD size.