Realization of vertical GaAs/InAs nanowire heterostructures on Si substrate

GaAs/InAs nanowire heterostructures are grown on Si(111) substrate by metal organic chemical vapor deposition via Au-catalyst vapor-liquid-solid mechanism. Nanowires vertical to the substrate are realized by using GaAs/AlGaAs buffer layers. Straight InAs wire is grown axially on the GaAs nanowire by inserting a composition-graded InxGa1-xAs buffer segment between the two lattice mismatched materials. This work helps open new possibilities for the integration of III-V nanowire heterostructures on Si.