Figure 3.

Morphology of annealed c-plane sapphire substrates before and after annealing of the Au catalyst layer. 2μm × 2μm AFM images of a 1-nm-thin Au layer on 1,200°C-annealed c-plane sapphire substrate before (a) and after annealing in the PLD chamber at 700°C for 5 min (b).