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 similar to 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 (Delta a(0)/a(0)=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. (c) 2005 American Vacuum Society.