title: Two-dimensionally grown single-crystal silicon nanosheets with tunable visible-light emissions.
abstract: Since the discovery of graphene, growth of two-dimensional (2D) nanomaterials has greatly attracted attention. However, spontaneous growth of atomic two-dimensional (2D) materials is limitedly permitted for several layered-structure crystals, such as graphene, MoS2, and h-BN, and otherwise it is notoriously difficult. Here we report the gas-phase 2D growth of silicon (Si), that is cubic in symmetry, via dendritic growth and an interdendritic filling mechanism and to form Si nanosheets (SiNSs) of 1 to 13 nm in thickness. Thin SiNSs show strong thickness-dependent photoluminescence in visible range including red, green, and blue (RGB) emissions with the associated band gap energies ranging from 1.6 to 3.2 eV; these emission energies were greater than those from Si quantum dots (SiQDs) of the similar sizes. We also demonstrated that electrically driven white, as well as blue, emission in a conventional organic light-emitting diode (OLED) geometry with the SiNS assembly as the active emitting layers. Tunable light emissions in visible range in our observations suggest practical implications for novel 2D Si nanophotonics.
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Kim
authors.forename: Jaejun
authors.initials: J
authors.lastname: Lee
authors.forename: Ji Ho
authors.initials: JH
authors.lastname: Sung
authors.forename: Dong-jae
authors.initials: DJ
authors.lastname: Seo
authors.forename: Ilsoo
authors.initials: I
authors.lastname: Kim
authors.forename: Moon-Ho
authors.initials: MH
authors.lastname: Jo
authors.forename: Byoung Wook
authors.initials: BW
authors.lastname: Kwon
authors.forename: Won Kook
authors.initials: WK
authors.lastname: Choi
authors.forename: Heon-Jin
authors.initials: HJ
authors.lastname: Choi