The Morphology and Cathodoluminescence of GaN Thin Films

Abstract

In this paper we compare gallium nitride (GaN) films grown by molecular beam epitaxy on sapphire (Al2O3), gallium arsenide (GaAs (111)B) and lithium gallate (LiGaO2) substrates. Atomic force microscopy, scanning electron microscopy, cathodoluminescence imaging and cathodoluminescence spectroscopy are used to characterise the films. From growth runs carried out to date, GaN films on GaAs substrates exhibit the best surface uniformity and the cleanest luminescence.