Abstract
The optical polarization properties in nonpolar AlGaN/AlN quantum wells (QWs) are investigated over the full range of Al compositions. The calculation predicts that the lowest energy optical transition in AlGaN layers pseudomorphically grown on unstrained AlN is dipole allowed for the electric field vector parallel to the [0001] direction, and that the degree of polarization is hardly affected by the AlGaN QW width regardless of the Al composition. Experimentally, AlGaN/AlN QWs () are homoepitaxially grown on AlN substrates. Photoluminescence spectroscopy reveals that the emissions of all QWs, including GaN/AlN QWs, are strongly polarized along the [0001] direction. This result agrees with the theoretical prediction.
- Received 16 November 2012
DOI:https://doi.org/10.1103/PhysRevB.87.041306
©2013 American Physical Society