  The optical emission of non-polar GaN/AlN quantum dots has been investigated.
The presence of stacking faults inside these quantum dots is evidenced in the
dependence of the photoluminescence with temperature and excitation power. A
theoretical model for the electronic structure and optical properties of
non-polar quantum dots, taking into account their realistic shapes, is
presented which predicts a substantial reduction of the internal electric field
but a persisting quantum confined Stark effect, comparable to that of polar
GaN/AlN quantum dots. Modeling the effect of a 3 monolayer stacking fault
inside the quantum dot, which acts as zinc-blende inclusion into the wurtzite
matrix, results in an additional 30 % reduction of the internal electric field
and gives a better account of the observed optical features.
