Dual-mode operation of 2D material-base hot electron transistors

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS 2 , in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS 2 in the base region) with the application of a negative collector-base potential (V CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of V CB . Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying V CB . We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.