On-State Current Optimization for SnSe2 Tunneling Field Effect Transistors with Silicene Electrodes

Improving the on-state currents (ION) is vital for the practical application of tunneling field-effect transistors (TFETs). A study on the possibility of lifting the ION for the SnSe2 TFET with a silicene electrode is then carried out with ab initio quantum transport calculations. The optimal configuration uses p- and n-type vdW silicene/SnSe2 as electrodes for the n- and p-type HetJ-TFET, respectively. Inspiringly, the ION enhancement for the n-type HetJ-TFET is approximately 30 times, and the subthreshold swing (SS) is only 37–38 mV/dec. The ION(LP) of 735 μA/μm at VDD = 0.5 V and ION(HP) of 801 μA/μm at VDD = 0.4 V of the optimal n-type SnSe2 HetJ-TFET exceed the IRDS LP and HP goals of 547 and 753 μA/μm at VDD = 0.6 V for the year 2037, respectively. The enhanced tunneling probability comes from the narrower tunneling barrier width and the varied tunneling path from the changed band dispersions by high hybridization. Our study proposes a feasible way to increase ION for TFETs.