1 research outputs found
Anomalous Strain Relaxation in Core–Shell Nanowire Heterostructures via Simultaneous Coherent and Incoherent Growth
Nanoscale substrates
such as nanowires allow heterostructure design
to venture well beyond the narrow lattice mismatch range restricting
planar heterostructures, owing to misfit strain relaxing at the free
surfaces and partitioning throughout the entire nanostructure. In
this work, we uncover a novel strain relaxation process in GaAs/In<sub><i>x</i></sub>Ga<sub>1–<i>x</i></sub>As
core–shell nanowires that is a direct result of the nanofaceted
nature of these nanostructures. Above a critical lattice mismatch,
plastically relaxed mounds form at the edges of the nanowire sidewall
facets. The relaxed mounds and a coherent shell grow simultaneously
from the beginning of the deposition with higher lattice mismatches
increasingly favoring incoherent mound growth. This is in stark contrast
to Stranski–Krastanov growth, where above a critical thickness
coherent layer growth no longer occurs. This study highlights how
understanding strain relaxation in lattice mismatched nanofaceted
heterostructures is essential for designing devices based on these
nanostructures