Ricerc@Sapienza

Graphene is a prototype one-atom-thick two-dimensional (2D) material and attracts huge interest due to its excellent transport properties, although the intrinsic zero-energy gap reduces its impact for the design of semiconductor nanodevices. In this project, we plan to realize a viable route to open the energy gap in graphene by wrapping the sp2 planar hybridization in a sp3 configuration. Hydrogenation can induce a sp3 distortion and semi-metallic graphene turns into semiconducting graphane.
Another limitation of graphene is the size of the sample/flakes and the scaling of the extraordinary 2D properties in samples suitable for industrial applications. It is useful to pack the individual 2D sheets into a 3D architecture to minimize the volume while increasing its surface area. The employment of a single graphene sheet in 3D devices is not straightforward, a strong research effort is oriented toward the design of 3D structures, preserving the remarkable properties of suspended 2D sheets. The design challenges of 3D nano-porous graphene (NPG) structures are focused on ensuring a topological structure with highly connected layers, negligible density of lattice and edge defects, to engineer physical and chemical properties for the desired functionalities.
We will obtain 3D graphane by ex-situ (plasma etching) and in-situ (atomic H by hot ribbon in ultra-high-vacuum, UHV), at different hydrogenation doses. We will study pristine and hydrogenated NPG with a multi-technique approach, combining x ray photoemission, optical measurements, to determine the electronic and optical properties of 3D graphane. We will exploit both on-campus laboratories (x-ray and uv photoemission, IR spectroscopy) and synchrotron radiation beamlines (spatially-resolved photoemission) at synchrotron radiation facilities.