Beyond graphene, which is intensively studied over more than one decade, the other related materials remain almost unexplored. The research activities in the field of other layered materials like phosphorene, arsenene, silicene and germanene are rapidly growing in the last few years. Compare to graphene, all these materials are non-zero band-gap semiconductors. This property opens new application possibilities in electronic and optoelectronic devices. The properties of 2D materials can be further controlled by their functionalization. The chemistry of materials beyond graphene is none explored and shows high application potential in many fields. Compare to the graphene and pnictogen group, the chemical exfoliation method mast be applied for synthesis of silicene / germanene derivatives using Zintl phase compounds like CaGe2
. Various methods well know from organic chemistry can be applied for synthesis of tetrel derivatives reaching almost complete derivatization of 2D material skeleton.