  Utilizing sp3d5s* tight-binding band structure and wave functions for
electrons and holes we show that acoustic phonon limited hole mobility in [110]
grown silicon nanowires (SiNWs) is greater than electron mobility. The room
temperature acoustically limited hole mobility for the SiNWs considered can be
as high as 2500 cm2/Vs, which is nearly three times larger than the bulk
acoustically limited silicon hole mobility. It is also shown that the electron
and hole mobility for [110] grown SiNWs exceed that of similar diameter [100]
SiNWs, with nearly two orders of magnitude difference for hole mobility. Since
small diameter SiNWs have been seen to grow primarily along [110] direction,
results strongly suggest that these SiNWs may be useful in future electronics.
Our results are also relevant to recent experiments measuring SiNW mobility.
