Abstract

Although the Graphene-Silicon (Gr-Si) based configurations have received extensive attention in electronics and optoelectronics, sufficient on/off current ratio I_on / I_off and new applications are still limited by conventional device structures. In this study, we show a new structure of vertical ambipolar barristors based on silicon-graphene-h-BN-graphene sandwich structure, which can be effectively modulated by the gate voltage for that the graphene is ambipolar. The bottom graphene acts as a gate-tunable “active contact” and the top graphene is used as the gate electrode with the help of the hexagonal boron nitride (h-BN) as a transparent dielectric layer. Under the influence of the gate voltage, the Gr-Si configuration can be flexible modulated with an ON-OFF ratio exceeding 10³. Besides, a normal photovoltaic properties of the devices has been characterized due to the application of its transparent two-dimensional materials. This unconventional Gr-Si configuration has a potential meaning for future electronics and optoelectronics based on graphene or other two-dimensional van der Waals heterostructures.