BCN-adsorbed germanenes

In this chapter, we display the optimal structures, spatial charge distributions, charge variations, band structures, and density of states of boron-, carbon-, and nitrogen-adsorbed germanene. The heights of buckling are drastically changed to be 2.210/2.367/1.938 Å and 2.455 /2.109/2.132 Å, respectively, for the single-side adsorbed and double-side adsorbed germanene. The boron atoms get stronger interaction with the horizon-neighboring germanium atoms, but the nitrogen has the stronger interactions with the germanium atoms blow. The calculated results all reveal that there exist very strong but complicated (2s, 2px, 2py, 2pz)-(4s, 4px, 4py, 4pz) sp3-orbital hybridizations. Even the double-side adsorbed cases exhibit like bilayer structures. When the first-principles electronic energy spectra along the high-symmetry paths are successfully simulated by the tight-binding model with the uniform & multi-/single-orbital hopping integrals, the diversified essential properties could be fully explored in the near-future studies, e.g., the rich and unique magnetic quantization phenomena, the quantum spin Hall effect, Coulomb excitation, and optical properties.