Blue phosphorus nanoscrolls

As an allotrope of black phosphorus, two-dimensional blue phosphorus (2D bP) has gained significant attention since the first realization of its growth through molecular beam epitaxy in 2016. In this paper, self-encapsulated blue phosphorus nanoscrolls (bPNSs) formed by rolling up 2D bP are found to be energetically favorable at room temperature, based on ab initio calculations. Our results demonstrate that these quasi-one-dimensional bPNSs are all semiconductors with wide-range band gaps varying from 0.02 to 1.8 eV for different scroll thicknesses and rolling directions. The electron mobility reaches as high as 6620 ${\mathrm{cm}}^{2}\phantom{\rule{0.16em}{0ex}}{\mathrm{V}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$ in armchair double-layer bPNSs, which is approximately 20-fold greater than that of a 2D bP monolayer. This study discovers the bPNSs as another class of semiconductors and proposes the scrolling strategy as an excellent candidate for the application of other 2D materials.