Channel Thickness Optimization for Ultrathin and 2-D Chemically Doped TFETs

The 2-D material-based TFETs are among the most promising candidates for low-power electronics applications since they offer ultimate gate control and high-current drives that are achievable through small tunneling distances (Λ) during the device operation. The ideal device is characterized by a minimized Λ. However, devices with the thinnest possible body do not necessarily provide the best performance. For example, reducing the channel thickness (T
_ch
) increases the depletion width in the source, which can be a significant part of the total Λ. Hence, it is important to determine the optimum T
_ch
for each channel material individually. In this paper, we study the optimum T
_ch
for three channel materials: WSe
₂
, black phosphorus, and InAs using full-band self-consistent quantum transport simulations. To identify the ideal T
_ch
for each material at a specific doping density, a new analytic model is proposed and benchmarked against the numerical simulations.