Evidence for Structural Phase Transitions Induced by the Triple Phase Line Shift in Self-Catalyzed GaAs Nanowires

• DOI: 10.1021/nl303323t
• Publication Date: 2012-09-17T13:43:36Z
• Authors: Xuezhe Yu; Hailong Wang; Jun Lu; Jianhua Zhao; Jennifer Misuraca; Peng Xiong; Stephan von Molnár
• Keywords: Line (geometry)

Self-catalyzed growth of GaAs nanowires are widely ascribed to the vapor–liquid–solid (VLS) mechanism due presence Ga particles at nanowire tips. Here we report synthesis self-catalyzed by molecular-beam epitaxy covering a large parameter space. By carefully controlling flux and its ratio with As flux, without exhibiting flat front produced. Using scanning electron microscopy high-resolution transmission microscopy, compare rate structure, especially near front, droplets. We find that regardless whether droplets present on top, have short wurtzite section following zinc-blende bulk structure. The terminated thin cap, while do not such cap. phase is attributed droplet wetting sidewall during growth, pinning triple line sidewall. zinc-blend/wurtzite/(zinc-blende) transitions end fully consistent shifting up progressive consumption in crystallization As. results imply an identical VLS for both types NWs, their intricate structures provide detailed comparison specific experimental verification recently proposed III–V semiconductor (Phy. Rev. Lett. 2011, 106, 125505). this as guideline, successfully demonstrated controllable fabrication two distinct axial superlattice NWs consisting zinc-blende/defect-section wurtzite/defect-section units.