Figure 27: AFM surface images of Zn0.96Mg0.04O/ZnO quantum well/Zn0.96Mg0.04O films on ZnO (0001). The scan size is 2 𝜇 m × 2 𝜇 m , and the 𝑧 -scales are 2.16 nm (E 1766) and 2.5 nm (E 2000). ZnMgO monolayer terraces with step height c or c/2 corresponding to two-dimensional layer by layer growth are visible. The total film thickness and the out-of-plane strain are 380 nm and 330 nm and −0.18% and −0.22% for E1766 and E2000, respectively [54].