ScN/GaN(11̅00): A New Platform for the Epitaxy of Twin-Free Metal-Semiconductor Heterostructures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38758973.
- Also identified by DOI 10.1021/acs.nanolett.4c00659 and PMC identifier 11140757.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We study the molecular beam epitaxy of rock-salt ScN on the wurtzite GaN(11̅00) surface. To this end, ScN is grown on freestanding GaN(11̅00) substrates and self-assembled GaN nanowires exhibiting (11̅00) sidewalls. On both substrates, ScN crystallizes twin-free thanks to a specific epitaxial relationship, namely ScN(110)[001]∥GaN(11̅00)[0001], providing a congruent, low-symmetry interface. The 13.1% uniaxial lattice mismatch occurring in this orientation mostly relaxes within the first few monolayers of growth by forming a near-coincidence site lattice, where 7 GaN planes coincide with 8 ScN planes, leaving the ScN surface nearly free of extended defects. Overgrowth of the ScN with GaN leads to a kinetic stabilization of the zinc blende phase, that rapidly develops wurtzite inclusions nucleating on {111} nanofacets, commonly observed during zinc blende GaN growth. Our ScN/GaN(11̅00) platform opens a new route for the epitaxy of twin-free metal-semiconductor heterostructures including closely lattice-matched GaN, ScN, HfN, and ZrN compounds.