(201ae) Detailed Characterization and Fabrication of 3DPrinted Graphene/Polymer Structures Forheterojunction-Devices with MoS2 and Other 2DNanomaterials

It is known that 2D nanomaterials (2DN) can be interfaced with one another to realize heterostructures with controlled or expanded properties that can be applied to achieve functional devices. Currently, such structures have been produced at nano- to micro-scale dimensions. Here we show that 3D printing of graphene/polymer composites can allow device fabrication with 2DN-heterostructures produced at larger and accessible scales, while leveraging their unique properties. For example, fusing graphene, a zero bandgap 2DN, and MoS2, a semiconducting 2DN, together can produce ultrafast optoelectronic switches due to their mismatched Fermi levels. As a first step towards this goal, graphene/polymer-MoS2-graphene/polymer junctions were produced via 3D printing and experiments were conducted to measure the carrier transport characteristics. The results from carrier-transport studied at cryogenic temperatures (25 K) to room temperature were analyzed to determine transport barriers, carrier concentrations, Coulomb blockade, inter-particle capacitance, conduction mechanism and opto-electronic response. Furthermore, the effects of mechanical strain in the 3D-printed heterostructure was investigated. We envision that these 3D printed structures with 2DNs will lead to an evolution of next-generation optoelectronic, electronic and electromechanical devices, which would be printed on-demand.

Keywords: Graphene, MoS2, carrier-transport, 3D printed heterostructure