Optical properties of wurtzite GaN/AlN quantum dots grown on non-polar planes: The effect of stacking faults in the reduction of the internal electric field

Abstract

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.

Crystal orientation effects on the optical properties of wurtzite GaN/AlN quantum dots on semi-polar substrates

“…In the case of quantum wells (QWs), the crystal orientation effect on optical characteristics of WZ GaNbased QWs has been studied [14][15][16]. Similarly, in the case of QDs, electronic and optical properties on non-polar QDs have been studied [15][16][17][18][19][20][21][22].…”