title: Triangular Black Phosphorus Atomic Layers by Liquid Exfoliation.
abstract: Few-layer black phosphorus (BP) is the most promising material among the two-dimensional materials due to its layered structure and the excellent semiconductor properties. Currently, thin BP atomic layers are obtained mostly by mechanical exfoliation of bulk BP, which limits applications in thin-film based electronics due to a scaling process. Here we report highly crystalline few-layer black phosphorus thin films produced by liquid exfoliation. We demonstrate that the liquid-exfoliated BP forms a triangular crystalline structure on SiO2/Si (001) and amorphous carbon. The highly crystalline BP layers are faceted with a preferred orientation of the (010) plane on the sharp edge, which is an energetically most favorable facet according to the density functional theory calculations. Our results can be useful in understanding the triangular BP structure for large-area applications in electronic devices using two-dimensional materials. The sensitivity and selectivity of liquid-exfoliated BP to gas vapor demonstrate great potential for practical applications as sensors.
authors.affiliation: Advanced Nano-surface Research Group, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Soonjoo
authors.initials: S
authors.lastname: Seo
authors.affiliation: Advanced Nano-surface Research Group, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Hyun Uk
authors.initials: HU
authors.lastname: Lee
authors.affiliation: Department of Applied Chemistry and Biological Engineering, Chungnam National University, Daejeon, 34134, Republic of Korea.
authors.forename: Soon Chang
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Advanced Nano-surface Research Group, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Yooseok
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Advanced Nano-surface Research Group, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Hyeran
authors.initials: H
authors.lastname: Kim
authors.affiliation: Spin Engineering Physics Team, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Junhyeok
authors.initials: J
authors.lastname: Bang
authors.affiliation: Advanced Nano-surface Research Group, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Jonghan
authors.initials: J
authors.lastname: Won
authors.affiliation: Department of Materials Science and Engineering, Hongik University, Seoul, 04066, Republic of Korea.
authors.forename: Youngjun
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Hongik University, Seoul, 04066, Republic of Korea.
authors.forename: Byoungnam
authors.initials: B
authors.lastname: Park
authors.affiliation: Advanced Nano-surface Research Group, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
authors.forename: Jouhahn
authors.initials: J
authors.lastname: Lee