Partially planar BP3 with high electron mobility as a phosphorene analog

摘要

Based on first-principles calculations, we propose a two-dimensional alpha BP3 crystal in which one quarter of the phosphorus atoms in phosphorene are substituted by boron atoms. Its geometrical structure resembles that of graphene more than that of phosphorene, although phosphorus is present as a major component. It is dynamically stable and energetically much more stable than another allotrope analogous to blue (beta) phosphorene. The alpha BP3 monolayer is a semiconductor with an indirect band gap (=0.77 eV) within the HSE06 calculation. For the BP3 bilayer, three stacking patterns are equally stable within 3 meV per atom. The monolayer exhibits a high electron mobility (similar to 4.6 x 10(4) cm(2) V-1 s(-1)) along the zigzag direction. In the bilayer, the mobility is similar to 200 times higher than that of the a phosphorene bilayer. Specifically, it is even higher (similar to 3.7 x 10(5) cm(2) V-1 s(-1)) and amounts to similar to 2500 times in one of the patterns. Therefore, the BP3 monolayer or bilayer will be useful as an n-type material in nanoelectronics through appropriate doping.