Polygonal nanotubes of multi-phase layered phosphorus

Jie Guan, Zhen Zhu, David Tomanek
Michigan State University, East Lansing, Michigan, United States
Similar to graphite, black phosphorus is a layered structure that can be exfoliated to monolayers dubbed phosphorene[1]. Similar to carbon nanotubes, which are related to few-layer graphene, we propose the existence of phosphorus nanotubes formed of phosphorene, Different from graphite, besides the black allotrope, layered phosphorus has three stable structural phases, called blue-P [2], γ-P and δ-P, which can be connected naturally. The fact that connected structures do not lie in a plane allows us to design nanotubes by connecting laterally nanoribbons of different phases. Unlike single-phase nanotubes consisting of a layer rolled up to a cylinder, multi-phase phosphorene nanotubes will have a polygonal cross-section, as shown in Fig. 1. Both single-wall and multi-wall phosphorene nanotubes may be constructed in this way. The availability of more than one structural phase offers much larger structural richness than the carbon counterpart with one single phase. Consequently, we find that the electronic properties of phosphorene nanotubes depend not only on the chiral vector that defines the edge structure, but also the presence of the individual phosphorene phases. In analogy to the successful synthesis of carbon nanotubes by ball milling of graphite, we believe that phosphorene nanotubes may be formed in the same way in an inert atmosphere.

[1] H. Liu et al. ACS Nano 8 (2014)
[2] Z. Zhu and D. Tomanek, Phys. Rev. Lett. (2014)

Figure 1

Structure of a polygonal nanotube obtained by interconnecting phosphorene nanoribbons with different phases.