InN/GaN quantum dots: Electronic and optical properties

In the framework of a tight-binding model we investigate the electronic and optical properties of self-assembled nitride quantum dots (QDs). Coulomb and dipole matrix elements are calculated from the single-particle wave functions, which include the underlying wurtzite crystal structure on an atomistic level. These matrix elements are used for the evaluation of optical properties. For different dot sizes of the investigated lens-shaped InN/GaN QDs, we analyze the excitonic absorption and emission spectra. Furthermore the influence of the intrinsic and strain-induced electrostatic built-in field on the spectra is addressed. For a small lens-shaped InN/GaN QD we predict a vanishing exciton ground state emission. For larger QDs, a bright ground state emission is found but with reduced oscillator strength.