Palladium catalyzed defect-free 〈110〉 zinc-blende structured InAs nanowires

In this study, Pd thin film is used as catalyst to grow epitaxial InAs nanowires on GaAs(111)_B substrate in a metal-organic chemical vapor deposition reactor to explore the growth mechanism and the effects of non-gold catalysts in the growth of III-V epitaxial nanowires. Through detailed morphological, structural and chemical characterization using scanning and transmission electron microscopy, it is found that defect-free zinc-blende structured epitaxial InAs nanowires are grown along the 〈110〉 directions with four {111} sidewall facets forming a diamond shaped cross-section. Furthermore, the interface between the nanowire/catalyst is found to be the uncommon {113} planes. It is anticipated that these zinc-blende structured InAs nanowires are grown via the vapor-liquid-solid mechanism. The defect-free nature of these nanowires arises from the non-〈111〉 growth direction and non-{111} nanowire/catalyst interface.