Molecular beam epitaxial growth of ZnO on Si substrate using ozone as an oxygen source

Epitaxial ZnO films have been grown on Si (111) substrates by molecular beam epitaxy using ozone as an oxygen source. An initial deposition of a Zn layer followed by its oxidation produces a Superior template for the subsequent ZnO growth. The reflection high-energy electron diffraction measurement suggests that the,initial Zn layer and ZnO film are rotated by 30degrees with respect to the Si substrate orientation. The X-ray diffraction measurement reveals that the as-grown ZnO films are strongly c-oriented and include no rotational domains. Although there exists a small trace of ZnO (10 (1) over bar1) domains, it easily disappears upon annealing at 1100degreesC for 1 min after growth. Low-temperature photoluminescence measurements indicate that the emission property is improved significantly after annealing. The bound-exciton emission at 3.354 eV is dominant and its full-width at half maximum is as small as 11 meV.