Few-layer Phosphorene: An Ideal 2D Material For Tunnel Transistors

TL;DR

Few-layer phosphorene exhibits ideal electronic properties such as suitable bandgap, low effective mass, and high mobility, making it a promising 2D material for high-performance, energy-efficient tunnel transistors with scalability to 6 nm channels.

Contribution

This paper demonstrates that few-layer phosphorene has optimal properties for TFET applications and outperforms existing TMD-based TFETs, supported by quantum transport simulations.

Findings

High ION of 1 mA/μm in phosphorene TFETs

ON/OFF ratio around 1e6 achieved

Scalability to 6 nm channel length and 0.2 V supply

Abstract

2D transition metal dichalcogenides (TMDs) have attracted a lot of attention recently for energy-efficient tunneling-field-effect transistor (TFET) applications due to their excellent gate control resulting from their atomically thin dimensions. However, most TMDs have bandgaps (Eg) and effective masses (m*) outside the optimum range needed for high performance. It is shown here that the newly discovered 2D material, few-layer phosphorene, has several properties ideally suited for TFET applications: 1) direct Eg in the optimum range ~1.0-0.4 eV, 2) light transport m* (0.15m0), 3) anisotropic m* which increases the density of states near the band edges, and 4) a high mobility. These properties combine to provide phosphorene TFET outstanding ION 1 mA/um, ON/OFF ratio~1e6, scalability to 6 nm channel length and 0.2 V supply voltage, thereby significantly outperforming the best TMD-TFETs in energy-delay products. Full-band atomistic quantum transport simulations establish phosphorene TFETs as serious candidates for energy-eficient and scalable replacements of MOSFETs.