  We present an eight-band k.p model for the calculation of the electronic
structure of wurtzite semiconductor quantum dots (QDs) and its application to
indium gallium nitride (InGaN) QDs formed by composition fluctuations in InGaN
layers. The eight-band k.p model accounts for strain effects, piezoelectric and
pyroelectricity, spin-orbit and crystal field splitting. Exciton binding
energies are calculated using the self-consistent Hartree method. Using this
model, we studied the electronic properties of InGaN QDs and their dependence
on structural properties, i.e., their chemical composition, height, and lateral
diameter. We found a dominant influence of the built-in piezoelectric and
pyroelectric fields, causing a spatial separation of the bound electron and
hole states and a redshift of the exciton transition energies. The
single-particle energies as well as the exciton energies depend heavily on the
composition and geometry of the QDs.
