Steep subthreshold swing tunnel FETs: GaN/InN/GaN and transition metal dichalcogenide channels

As the understanding of tunnel field-effect transistors (TFET) advances, new approaches are emerging to lower off-currents, lower defect density in tunnel junctions, and to increase the highest current at which the subthreshold swing of 60 mV/decade (I
₆₀
) appears. III-N heterojunctions and transition-metal-dichalcogenide (TMD) materials are forcing some new thinking in junction design and doping.