First-principle prediction of the electronic property and carrier mobility in boron arsenide nanotubes and nanoribbons

Abstract

In this work, the electronic structure and carrier mobility of single-walled boron arsenide nanotubes (BAsNTs) have been systematically studied by using Boltzmann transport equation with the relaxation time approximation. We found that the ionic characteristic of B–As bond results in the dipole shells in the optimized BAsNTs. It is predicted that both zigzag BAs nanotubes (ZNTs) and armchair BAs nanotubes are semiconductors, and the strong σ*–π* hybridization in small ZNTs leads to a rapid drop of bandgap with a decrease of radius. Interestingly, as the size (n) of the NTs decreases, the hole mobility (μh) of ZNTs has an evident 3p (p is an integer) oscillation but electron mobility (μe) basically falls down, which falls even faster when the radius gets smaller. Comparing the carrier mobility between BAsNTs and its unzipping nanoribbons, we found that rolling BAs nanoribbons (BAsNRs) into BAsNTs would increase the μe but decrease the μh. The different behavior of the carrier mobility in BAsNRs and BAsNTs results from their distinct bond features of edge states, which vary with different widths (for BAsNRs) or radii (for BAsNTs).