GaN/AlGaN superlattices for optoelectronics in the mid-infrared

In this work we discuss the optical properties of a GaN/Al0.11Ga0.89N multiple‐quantum‐well structure grown on 4H‐SiC by plasma‐assisted molecular‐beam epitaxy. Photoluminescence lines related to the fundamental and excited electronic levels are identified, in good agreement with simulations of the electronic structure. Temperature dependence studies reveal an anomalous behaviour with quenching of the e1–hh1 while the e2–hh1 line becomes dominant at room temperature. This behaviour could be explained by the increasing thermal population of the e2 state and the higher radiative efficiency of the e2–hh1 transition compared to the e1–hh1 transition due to the intense electric field in the well. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)