Two-Dimensional MSi2N4 Heterostructure P-Type Transistors With Sub-Thermionic Transport Performances

Power dissipation has become a great challenge impeding the advancement of CMOS technology, due to the Boltzmann tyranny of Fermi-Dirac electrons. Here, we present that 2D lateral MSi2N4 (M=Nb, Ta, Mo, W) metal-semiconductor heterostructures can break through the fundamental thermionic limitation, serving as sub-thermionic rectifier diodes and p-type steep-slope field-effect transistors (FETs). Specially, the rectification ratio of 2D MSi2N4 heterostructure diodes is up to $10^{{10}}$ with the ideality factor reduced to 0.24. Moreover, the sub-threshold swing (SS) for 2D MSi2N4 heterostructure FETs ranges 10–30 mV/dec with on-current reaching 2100 and $1200~\mu \text{A}/\mu \text{m}$ for high-performance and low-power applications, respectively, which is much higher than that of tunneling FETs and comparable with other 2D metal-oxide-semiconductor FETs. This work demonstrated that 2D MSi2N4 family has great potential for making sub-thermionic electronic devices, and provides novel opportunities to overcome power consumption challenge of next-generation electronics based on 2D materials.