Self-assembled ZnO hexagonal nano-disks grown by radio-frequency magnetron sputtering

This paper reports synthesis and characterization of self-assembled ZnO hexagonal nano-disks grown by radio-frequency magnetron sputtering. X-ray diffraction data and scanning electron microscopy data show that ZnO hexagonal nano-disks are nucleated on top of the flat surfaces as the film thickness reaches 1.56 μm and then the number of nano-disks increases with the film thickness. The lateral size of hexagonal nano-disks is ∼720 nm and height is ∼74 nm. Strong photoluminescence spectra are also obtained, that is attributed to surface exciton emission at 3.3628 eV from the surface states of hexagonal nano-disks.

► Self-assembly of ZnO hexagonal nano-disks were grown by the radio-frequency magnetron sputtering method. ► Formation of ZnO hexagonal nano-disks depends strongly on the sputtering pressure. ► Strong surface exciton emissions in photoluminescence spectra were observed, that originates from the surface states of ZnO hexagonal nano-disks.