posted on 2024-01-03, 01:14authored byLu Qiu, Yuewen Mu, Sung Youb Kim, Feng Ding
Due to boron’s
unique bonding nature, planar boron materials,
including borophenes, boron nanoclusters, and nanoribbons, show very
puzzling features, especially the superior stability of the free-standing
planar boron edges. Here, we present a systematic investigation of
the bonding configurations of various edges of borophene. Because
of the flexibility of forming either three-center two-electron (3c–2e)
or two-center two-electron bonds (2c–2e), an edge of borophene
tends to be self-terminated by adopting a different bonding configuration
at the edge from that in bulk. Among various borophene edge types,
the double-chain-terminated flat edge is found to be significantly
stable. As a consequence, we found that the double- and triple-chain
borophene nanoribbons with a triangular lattice and wider ribbons
with hexagonal holes in the central area are more stable than the
quadruple-chain borophene nanoribbon. This study greatly deepens our
understanding of the bonding configurations, electronic properties,
and stabilities of planar boron nanostructures and paves the way for
the rational design and synthesis of various boron materials.