Performance Investigation of p-FETs Based on Highly Air-Stable Monolayer Pentagonal PdSe2

Pentagonal PdSe
₂
is a promising candidate for layered electronic devices due to its high air stability and anisotropic transport properties. Here, we investigate the performance of p-type field-effect transistors (p-FETs) based on PdSe
₂
monolayer using a multiscale simulation framework combining density functional theory and quantum transport. We find that monolayer PdSe
₂
devices show excellent switching characteristics (< 65 mV/dec) 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 the channel length can be easily scaled down to 7 nm without any significant compromise in the performance. Going below 7 nm, we find that there is a severe degradation in the subthreshold swing for a 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 the ON-state current and the switching performance.