High quality AlSb bulk material on Si substrates using a monolithic self-assembled quantum dot nucleation layer

Abstract

We report and characterize the growth of defect-free AlSb bulk material on Si (001) substrates using a monolithic self-assembled AlSb quantum dot (QD) nucleation layer. During the first few monolayers of AlSb growth on Si, highly crystalline QDs form. With continued deposition, the islands coalesce into a planar material with no detectable defects. The QD nucleation layer facilitates a completely relaxed AlSb within ∼100 ML of deposition according to x-ray diffraction. We attribute the success of AlSb growth on Si to both the large AlSb∕Si lattice mismatch (Δa0∕a0=13.5%) in combination with the strong AlSb atomic bond. We also demonstrate room temperature photoluminescence from an InGaSb QW grown on the AlSb bulk layer.