Wurtzite MgxZn1-xS (0≤x≤0.25) thin films have been epitaxially grown on (0001) Al2O3using pulsed-laser deposition. High-quality films can be prepared at a growth temperature of 450-550°C with (0001) ω-rocking curve full width at half maximum as narrow as 0.09°. High-resolution cross-sectional transmission electron microscopy of the films deposited at 500°C shows the presence of the mixture of zinc-blende and wurtzite phases at the interface, and therefore the interfacial region is highly defective. However, above the critical thickness of ∼5 nm, the film bulk consists of pure wurtzite material with a very high level of crystallinity. The band edge of MgxZn1-xS films examined by transmission spectroscopy at room temperature increases from 3.75 eV at x=0 to 3.95 at x=0.25.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)