  Pentagonal PdSe2 is a promising candidate for layered electronic devices,
owing to its high air-stability and anisotropic transport properties. Here, we
investigate the performance of p-type FET based on PdSe$_2$ mono-layer using
multi-scale simulation framework combining Density functional theory and
quantum transport. We find that mono-layer PdSe$_2$ devices show excellent
switching characteristics ($<$ 65 mV/decade) for the source-drain direction
aligned along both [010] and [100] directions. Both directions also show good
on-state current and large transconductance, though these are larger along the
[010] direction for a 15 nm channel device. The channel length scaling study of
these p-FETs indicates that channel length can be easily scaled down to 7 nm
without any significance compromise in the performance. Going below 7 nm, we
find that there is a severe degradation in the sub-threshold swing for 4 nm
channel length. However, this degradation can be minimized by introducing an
underlap structure. The length of underlap is determined by the trade-off
between on-state current and the switching performance.
