Optically pumped lasing of GaN/AlGaN structures grown along a non‐polar crystallographic direction

Abstract

AbstractDue to their undesirable spontaneous and piezoelectric polarizations, nitride structures grown along polar directions are subject to high built‐in electric fields. A promising means of overcoming the effects related to built‐in electric fields and, thereby, obtaining higher quantum efficiencies is to grow nitrides along a non‐polar direction. It is our intention to report our recent progress on non‐polar homo‐epitaxial structures grown by PAMBE along the (11$/bar 2$0) non‐polar direction. As a substrate we used GaN bulk crystals grown by the High Pressure Solution method and overgrown by HVPE. As has been previously reported, non‐polar AlGaN/GaN quantum wells possess sharp excitonic lines. We are able to present optically pumped laser action on separate confinement heterostructures. Laser action is clearly proved by spontaneous emission saturation, abrupt line narrowing, and the strong TE polarization of output light. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)