Band‐to‐Band Tunneling Control by External Forces: A Key Principle and Applications

Band‐to‐band tunneling (BTBT) devices with superior subthreshold swing directly related to on/off switching speed and power consumption efficiency have emerged as a breakthrough of the limitation in conventional metal‐oxide‐semiconductor field‐effect transistors (MOSFETs). However, it is difficult to reach a higher level of electrical characteristics with only a combination of materials based on their intrinsic characteristics. External forces, such as electric fields, light, and temperature, can modulate the electron and hole concentration and control the tunneling probability and the electrical characteristics of heterostructure electronics. Recent articles employing external forces to improve the BTBT performance and demonstrate the mechanism of BTBT devices are summarized with five representative external forces. Moreover, the utility of the external force‐induced performance improvement of the BTBT device is also discussed by providing various applications. An external force is a promising candidate for enhancing band‐to‐band tunneling or providing multifunctionality to a tunneling device. This paper summarizes the effects of five representative external forces on the performance of the tunneling device. Moreover, this paper demonstrates the applications that are improved or become versatile through the influence of external forces.