GaAs layer on c-plane sapphire for light emitting sources

High-quality cubic GaAs (111)A buffer layers have been grown on an atomically flat c-plane trigonal sapphire substrate having well-defined steps and terraces. A two-step growth method has used where, at early stage, a layer low temperature (LT), followed by second high-temperature layer. In addition to the process, AlAs nucleation multiple annealing employed. The effectiveness of LT in this highly dissimilar epitaxy was then investigated. An resulted relaxed with smooth surface morphology high crystalline quality. InGaAs quantum well (QW) epitaxially 70 nm compared reference QW substrate. Along x-ray high-resolution cross-section transmission electron microscopy, comparable photoluminescence intensity linewidth respect confirmed our strategies produce high-quality sapphire. This demonstrates opportunity for photonics potential realise integrated microwave photonic chip platform.