Design of a P-type cold-source field-effect transistor with 2D MA 2 Z 4 : a study toward performance limits

Abstract By integrating the excellent electrostatic control capability of two-dimensional semiconductors with the ‘cold source’ device concept, this work proposes a low-power p-type field-effect transistor design based on MA 2 Z 4 materials, using monolayer MoSi 2 N 4 as the channel and its metallic counterpart TaSi 2 N 4 as the source and drain electrodes. First-principles-based quantum transport simulations reveal that the TaSi 2 N 4 /MoSi 2 N 4 interface forms a high-quality p-type ohmic contact with a contact resistance as low as 748.1 Ω μ m. Benefiting from the carrier-filtering effect induced by the characteristic bandgap near the Fermi level in the ‘cold source’ TaSi 2 N 4 , the proposed device exhibits outstanding switching performance: at a low source-drain voltage, it delivers an on-state current up to 1610 μ A μ m −1 , an off-state current as low as 0.05 μ a μ m −1 , a switching ratio exceeding 3 × 10 4 , and a near-ideal subthreshold swing of 64.5 mV dec −1 .