Enhanced interband tunneling in two-dimensional tunneling transistors through anisotropic energy dispersion

The unsatisfactory transmission probability in tunneling junction is a major challenge that restricts the performance and scaling of next-generation nanodevices, such as the tunnel field-effect transistors (TFETs). Here, we propose a strategy utilizing anisotropic electronic structures to enhance the inter-band tunneling performance. In the tunneling process, the sharp energy dispersion in transport direction ensures a high transmission eigenvalue, and the weak transverse energy state can broaden the transverse tunneling window, thus strengthening the tunneling probability. Furthermore, our quantum transport simulations demonstrate that in two-dimensional (2D) group VA-VA TFETs, the stronger anisotropic band structures make 2D BiAs and arsenene exhibit high on-state current several times higher than other systems, and the relative larger bandgap of arsenene also gives rise to a steep subthreshold slope below 60 mV/dec. This work provides a physical understanding of the tunneling transport performance, and the anisotropic 2D electronic structures can be regarded as a target feature to design tunneling transistors.

Automated summary

This study proposes a strategy to enhance the inter-band tunneling performance by utilizing anisotropic electronic structures. The sharp energy dispersion in the transport direction and weak transverse energy state can enhance the tunneling probability. Quantum transport simulations demonstrate that in 2D VA-VA TFETs, stronger anisotropic band structures can increase the on-state current and achieve a steep subthreshold slope.