Structural and emission improvement of cyan-emitting InGaN quantum wells by introducing a large substrate misorientation angle

Abstract

Within this work, we studied InGaN QWs with nominally 17% InN mole fraction grown within an 80 × 80 μm area with local misorientation angle change from 0.3° to 3.2°. We observed a significant improvement of the photoluminescence intensity for the area with misorientation above 1.5°, which we attribute to the quenching of nonradiative recombination processes. From the structural point of view, the increase of the misorientation angle above 1.5° is accompanied by the improvement of the morphology of the sample and quality of the quantum wells observed through atomic force microscopy and transmission electron microscopy. We show that the structural and emission qualities in high-InN- mole fraction layers can be improved just by increasing the misorientation angle of the substrate and that the improved qualities are preserved even for large misorientation angles.