  Ultrascaled GaSe field effect transistors are investigated through ab initio
calculations. GaSe monolayers, 3 nm long, exhibit excellent performance with
reduced short-channel effects and considerable high ON-current. Such device
characteristics are due to the valence band edge shape, which leads to very
heavy holes in the transport direction and eventually suppresses intraband
tunneling, detrimental for correct operation in the OFF state.
