Figure 1From: Electronic structures and optical properties for Ag-N-codoped ZnO nanotubes(8,0) ZnO nanotube. (a) Ag atom doped at 1 site and N atoms which can be doped at 2, 3, 4, 5, and 6 sites. (b) Top view of (8,0) ZnO nanotube. Red and gray balls represent O and Zn atoms, respectively.Back to article page