Electronic and electron emission properties of X/ZnO monolayer (X=Li, Na, K, Rb, or Cs): A first-principles study

摘要: Abstract Two-dimensional (2D) materials have attracted increasing research interest due to their unique physical and chemical properties. As a typical 2D material, ZnO monolayers not only generate scientific but also may important technological applications. However, it is still great challenge for be used in electron emission devices. Here, the first-principles calculations based on DFT + D2 been investigate structural stabilities, electronic structure, properties diffusion behaviors of X/ZnO (X = Li, Na, K, Rb, or Cs) monolayers. The results demonstrate that top center hexagonal ring Zn–O most stable adsorption site alkali metal X adsorbed onto band gaps are reduced zero, exhibit metallic characteristics. Furthermore, after adsorption, monolayer, including work function, ionization potential Fermi levels, rapidly improved amount charges transferred from substrate. In addition, monolayer suggest adatoms favor formation nanotemplate monolayer. These findings provide guidance extend applications low-dimensional