Strong graded interface related exciton energy blueshift in InxGa1−xN/GaN quantum dots

The role of graded interfaces on the carrier confinement and exciton properties of wurtzite InxGa1−xN/GaN quantum dots is investigated. The internal electric field inside the dot generated by the spontaneous and piezoelectric polarizations is considered, as well as the existence of graded interfaces, which reduces the strain. It is shown that the existence of graded interfaces enhances appreciably the energies of the confined carriers and excitons. Graded interface related blueshifts of the electron–heavy hole confined exciton energy is demonstrated to be as high as View the MathML source for quantum dot sizes ranging from 30 to View the MathML source and interface thicknesses varying from 5 to View the MathML source.