Visible photoluminescense of the (1120), (1011) and (0001) surfaces of ZnO nanofilms

摘要

Thin ZnO nanofilms 25 nm thick with (0001), (1120) and (1011) as surfaces were grown epitaxially on the NaCl (111) and (001) surfaces. The room temperature photoluminescence (PL) spectrum from the (1120) nanofilm has a sharp UV emission but negligible green emission, indicating that it has good quality and low defect density. However, the PL spectra from the (1011) and (0001) surface nanofilms have a broad green emission, and that of the (1011) surface is stronger than the (0001) surface. The result supports that the surface oxygen vacancies are the probable origins of the green emission.