Green luminescent zinc oxide films prepared by polymer-assisted deposition with rapid thermal process

Highly c-axis-oriented zinc oxide (ZnO) films with nano-size grains were successfully prepared on sapphire (0001) substrates by polymer-assisted deposition, where the crystallization of the ZnO was realized by a rapid thermal process (RTP). Post-processing conditions played critical roles in the structure, surface morphology, and the photoluminescence (PL) spectra of the films. The post-thermal treatment by RTP enhances the green PL of the ZnO films. Oxygen vacancies induced by the RTP may be related to the green PL from undoped ZnO.