Concluding remarks

This chapter includes the most significant results of the previous chapters, which is able to clearly illustrate the diverse phenomena through the outstanding candidates of the germanium-/germanene-related materials. A plenty of critical factors have been successfully covered in the numerical calculations: dimensionalities, stacking configurations, layer numbers, buckled/planar honeycomb lattices, quantum confinements/chiralities of nanotubes and nanoribbons, chemical adsorptions and substitutions, composites of two monolayer subsystems, heterojunctions/substrate effects, Ge-based battery electrolytes, solar cells, intermetallic compounds and ferromagnetics, and few-layer antimonene without/with substrate. Various chemical environments are capable of providing a sufficient platform in predicting the rich and unique physical/chemical/material properties, identifying the diverse phenomena and thus realizing the highly potential applications. Strong relations between two theoretical approaches are fully discussed.