Effect of material parameters on two-dimensional materials based TFETs: An energy-delay perspective

In this paper, we study the impact of material parameters (i.e. effective mass and bandgap) for two-dimensional (2D) material based tunneling FETs (TFETs) on circuit level metrics. We estimate circuit level metrics (i.e delay and energy consumption) of 2D TFETs at different target OFF current (IOFF) for various combination of material parameters. To fulfill a given IOFFrequirement for circuit level metrics, we study the the impact of effective mass and bandgap of the material on device level metrics such as sub-threshold slope, and IOFF. It is observed that it is imperative to have a smaller bandgap irrespective of higher effective mass of the material to achieve minimum energy-delay product (EDP) for a given delay or frequency of operation. The challenge with small bandgap materials is to curb ambipolar currents to meet target IOFFwhich poses a limit on the maximum performance achieved from the small bandgap material TFETs.