Two-Dimensionally Layered p-Black Phosphorus/n-MoS2/p-Black Phosphorus Heterojunctions.

Layered heterojunctions are widely applied as fundamental building blocks for semiconductor devices. For the construction of nanoelectronic and nanophotonic devices, the implementation of two-dimensional materials (2DMs) is essential. However, studies of junction devices composed of 2DMs are still largely focused on single p-n junction devices. In this study, we demonstrate a novel pnp double heterojunction fabricated by the vertical stacking of 2DMs (black phosphorus (BP) and MoS2) using dry-transfer techniques and the formation of high-quality p-n heterojunctions between the BP and MoS2 in the vertically stacked BP/MoS2/BP structure. The pnp double heterojunctions allowed us to modulate the output currents by controlling the input current. These results can be applied for the fabrication of advanced heterojunction devices composed of 2DMs for nano(opto)electronics.