Self-Seeded Growth of GaAs Nanowires by Metal–Organic Chemical Vapor Deposition

Abstract

Self-seeded growth of semiconducting nanowires offers significant advantages over foreign metal-seeded growth by eliminating seed-associated impurities. However, density and diameter control of self-seeded nanowires has proven challenging although it is required for integration of nanowires into optoelectronic devices. We report the self-seeded growth of GaAs nanowire arrays on GaAs (111)­B, (110), and (111)­A substrates by metal–organic chemical vapor deposition. Our approach involves two steps: the <i>in situ</i> deposition of Ga seed particles and subsequent GaAs nanowire growth. Control of nanowire diameter and array density is achieved via Ga seed deposition temperature and substrate orientation; increased seed deposition temperatures or changing substrate orientation from (111)­A to (110) and (111)B yields reduced areal density and larger nanowire diameters. The density and diameter control approaches could be extended to other self-seeded III–V nanowire material systems