Assembly of suspended graphene on carbon nanotube scaffolds with improved functionalities

With self-assembly being an efficient and often preferred process to build micro- and nano-materials into ordered macroscopic structures, we report a simple method to assemble monolayer graphene onto densified vertically aligned carbon nanotube (CNT) micropillars en route to unique functional three-dimensional microarchitecture. This hybrid structure provides new means of studying strain induced in suspended graphene. The strain induced could be controlled by the size and number of supporting microstructures, as well as laser-initiated localised relaxation of the graphene sheet. The assembled structure is also able to withstand high-energy electron irradiation with negligible effect on the electrical properties of the hybrid system. The hybrid system was further functionalised with quantum dots on the CNTs with the assembled top graphene layer as a transparent electrode. Significant improvements in photocurrent were achieved in this system.