Hexagon-on-cube versus cube-on-cube epitaxy: The case of ZnSe(111) on SrTiO3(001)
Résumé
The structure of ZnSe epilayers grown by molecular-beam epitaxy on SrTiO3 001 substrates has been studied using electron diffraction, x-ray diffraction, and electron microscopy. ZnSe, like certain other zincblende semiconductors, grows epitaxially along the 111 direction, contrary to what is expected from considerations on lattice registry and mismatch. First-principles calculations based on density-functional theory show that this peculiar epitaxy results from the subtle balance between strain and interface bonding during the growth of the first layer.