Electron microscopy of AlGaN-based multilayers for UV laser devices

UV-Laser technology is one of the most challenging and important areas in nitride semiconductor research. A new growth technology, using a thin GaN interlayer approach, has recently been developed for UV-LEDs in our department. Improved optical quality of so grown LEDs has been demonstrated. A similar growth approach has now been used to grow an UV-laser structure that has shown stimulated emission (lasing) at ∼340 nm via optical pumping. We report here a study of the microstructure, the epitaxial quality and the elemental distributions of such an aluminium gallium nitride-based heterostructure using a combination of various electron microscopy techniques.