Strain-tuning PtSe2for high ON-current lateral tunnel field-effect transistors

Abstract

We use full-band quantum transport simulations to show that monolayer platinum diselenide (PtSe2) tunnel field-effect transistors (TFETs) can deliver high ON currents (ION) under biaxial tensile strain, while maintaining a sub-60 mV/dec subthreshold swing. When strained, monolayer PtSe2 develops a lower effective mass and a small gap across which an efficient tunneling can occur, translating to a high ION when used in a TFET channel. At a drain voltage of 0.8 V and OFF current of 1 × 1 0 - 7 μ A / μ m, a simulated device with a 5% strained channel has an ION > 116 μ A / μ m, which is three orders of magnitude greater than that of the unstrained unoptimized device. The corresponding I60 is also increased by 600 times. This improvement comes at a reasonable cost of degradation in the OFF state and has a minimal effect on the switching characteristics down to 10 nm channel length. Our results present the mechanical flexibility of 2D materials as a powerful tuning parameter toward their use in high-performance tunneling devices.