Effects of annealing temperature of buffer layer on structural and optical properties of ZnO thin film grown by atomic layer deposition

ZnO thin film was deposited on Si substrate with the insertion of ZnO buffer layer, which was annealed at various temperatures between 600 and 900 ∘C. ZnO thin film was grown by Atomic layer deposition (ALD) technique and the ZnO/ZnO-buffer/Si films have been further annealed for 30 min in N2 ambient. High quality ZnO thin films were obtained on the annealed ZnO-buffer/Si layer. In particular, the ZnO thin film that is grown on 750 ∘C-annealed ZnO buffer exhibits a smoother surface, and enhanced near-band-edge emission compared to those grown on the as-prepared ZnO buffer layer. In the meantime, ZnO with 900 ∘C-annealed ZnO buffer layer shows the narrowest and strongest (002) peak from the XRD measurement.