Interband tunneling in two-dimensional crystal semiconductors

Interband quantum tunneling of electrons in semiconductors is of intense recent interest as the underlying transport mechanism in tunneling field-effect transistors. Such transistors can potentially perform electronic switching with lower energy than their conventional counterparts. The recent emergence of two-dimensional (2D) semiconducting crystals provides an attractive material platform for realizing such devices. In this work, we derive an analytical expression for understanding tunneling current flow in single-layer 2D crystal semiconductors in the k-space. We apply the results to a range of 2D crystal semiconductors, and compare it with tunneling currents in three-dimensional semiconductors. We also discuss the implications for tunneling devices.