Control of the interfacial abruptness of Au-catalyzed Si-Si1−xGex heterostructured nanowires grown by vapor–liquid–solid

Abstract

Axial Si-Si1−xGex heterostructured nanowires were grown by Au-catalyzed vapor–liquid–solid method. In this work, the authors examine the changes in growth parameters on the interfacial-abruptness of Si-Si1−xGex heterointerfaces in nanowires. The authors have investigated the effect of temperature drop, pressure change, and growth stop on the droplet stability which in turn modifies nanowire morphology and interfacial abruptness. The authors found that Si/Si1−xGex heterointerface is relatively sharp while Si1−xGex/Si is much broader. They demonstrate that a short growth stop is a good way to minimize reservoir effect resulting in small interfacial abruptness value. Our observations reveal that Si/Si1−xGex interfacial abruptness is 20 ± 5 nm irrespective of the nanowire diameter while interfacial abruptness for Si1−xGex/Si is linearly dependent on nanowire diameter.