As
the lightest two-dimensional (2D) metal, borophene was rarely
applied in semiconductor devices. The recently synthesized hydrogenated
borophene (B8H4) opens up the possibility for
2D boron-based semiconductors. Here, by first-principles calculations,
we evaluate the potential application of B8H4 in nanoscale field-effect transistors (FETs). We disclose the tunable
electronic properties of monolayer B8H4 under
strain engineering and the promising electrical performance of B8H4-based FETs in the ballistic transport regime.
We also reveal that pristine B8H4-FETs can fulfill
the ITRS (International Technology Roadmap for Semiconductors) requirement
for high-performance devices with 5 nm channel length in terms of
on-current, delay time, and power-delay product. Moreover, 5% biaxial
compressive strain can further scale B8H4-FETs
down to 3 nm gate length. This study unveils the potential applications
of B8H4 in sub-5 nm FETs and underlines the
promising role of boron-based semiconductors in future nanoelectronics.