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

摘要

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 150 meV for quantum dot sizes ranging from 30 to 96 Angstrom and interface thicknesses varying from 5 to 15 Angstrom. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 7]