Significant enhancement of hole mobility in [110] silicon nanowires compared to electrons and bulk silicon

TL;DR

This paper demonstrates that [110] silicon nanowires exhibit significantly higher hole mobility than electrons and bulk silicon, with potential applications in future electronic devices due to their superior transport properties.

Contribution

The study reveals that [110] silicon nanowires have much higher hole mobility than electrons and bulk silicon, highlighting their potential for electronic applications.

Findings

Hole mobility in [110] SiNWs can reach 2500 cm2/Vs.

Hole mobility exceeds electron mobility in [110] SiNWs.

[110] SiNWs outperform [100] SiNWs in mobility by nearly two orders of magnitude.

Abstract

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.