From graphene to borophene the fascinating 2D materials
We first predicted the boron sheets long before the synthesis of carbon sheets. Both are single-atom-thick one-layer sheets called respectively borophene and graphene. Short historical developments of boron and carbon sheets are given and the most important theoretical and experimental studies are mentioned. The derivatives of graphene are listed and the variety of hexagonal holes in borophene is recorded. Some of their geometrical, electronic, and optical properties are introduced.