  Tin monoxide is an interesting two-dimensional material because of the rare
oxide semiconductor with bipolar conductivity. However, the lower room
temperature mobility limits the applications of SnO in the future. Thus, we
systematically investigate the effects of the different layer structures and
strains on the electron-phonon coupling and phonon-limited mobility of SnO. The
A2u phonon mode in the high frequency region is the main contributor coupling
with electron for the different layer structures. And the orbital hybridization
of Sn atoms existing only in bilayer structure changes the conduction band edge
and decreases the electron-phonon coupling conspicuously, thus the electronic
transport performance of bilayer is superior to others. In addition, the
compressive strain of -1.0% in monolayer structure makes CBM consist of two
valleys at Gamma point and along M-Gamma line, also leads to the intervalley
electronic scattering assisted by Eg-1 mode. However, the electron-phonon
coupling regional transferring from high frequency (A2u) to low frequency
(Eg-1) results in the little significant change of mobility.
