Controlled fabrication of electrically contacted carbon nanoscrolls

Abstract

Carbon nanoscrolls (CNS) with their open ended morphology have recently attracted interest due to the potential application in gas capture, biosensors and interconnects. However, CNS currently suffer from the same issue that have hindered widespread integration of CNTs in sensors and devices: formation is done ex situ, and the tubes have to be placed with precision and reliability-a difficult task with low yield. Here, we demonstrate controlled in situ formation of electrically contacted CNS from suspended graphene nanoribbons with slight tensile stress. Formation probability depends on the length to width aspect ratio. Van der Waals interaction between the overlapping layers fixes the nanoscroll once formed. The stability of these CNSs is investigated by helium nano ion beam assisted in situ cutting. The loose stubs remain rolled and mostly suspended unless subject to a moderate helium dose corresponding to a damage rate of 4%-20%. One CNS stub remaining perfectly straight even after touching the SiO substrate allows estimation of the bending moment due to van der Waals force between the CNS and the substrate. The bending moment of 5400 eV is comparable to previous theoretical studies. The cut CNSs show long-term stability when not touching the substrate.

The morphology of doubly-clamped graphene nanoribbons

“…For a defect concentration of about 37%, as reached before with focused ion beam amorphization of free-standing graphene [34], the elastic modulus is predicted to be half that of the pristine material [41]. This effect may account for the observed onset of scrolling at L = 600 for w i = 100 nm, which is about half the value reported for pristine samples [27]. For bilayer graphene we do not observe any scrolling and only minimal crumpling at higher aspect ratios.…”

“…While our experimental design does not allow monitoring the deformation process in situ, scrolling and folding have been described to happen spontaneously [27,28,30]. There are several possible routes, which may induce the observed changes.…”

“…Most studies have concentrated on freely moving ribbons, limiting the available spatial control; scrolling of doubly clamped nanoribbons has attracted less attention [26][27][28][29]. For these ribbons, scrolling is a length-dependent process, happens spontaneously, and is attributed to residual stress in the membrane [27,28]. Due to the boundary condition, the energy gained by minimizing the surface has to balance the resulting strain.…”

Graphene Nanoribbon as Potential On-Chip Interconnect Material—A Review

“…The atomic structures and geometric properties of the graphene nanoribbon (GNR) interconnect strongly depend on its synthesis techniques. Depending on the pattern and structure, metallic or semiconducting GNR interconnects are produced [8,42].…”

Boron nitride nanoscrolls: Structure, synthesis, and applications

“…Amongst the aforementioned dimensionalities, of utmost importance and largely underexplored are boron nitride nanoscrolls (BNS); flat boron nitride nanosheets (BNNS) rolled into a spiral-like morphology with a 1D scroll structure, and consisting of hollow cores with a unique open-ended morphology, and offering a large surface to volume area (see Figure 2a). Essentially, BNS are structural analogs of carbon nanoscrolls (CNS) [44][45][46][47][48], possessing exotic physiochemical properties that are strikingly dissimilar in electrical and insulating properties to CNT [49], and CNS [50][51][52], i.e., in contrast to CNTs, the electrical properties and band gap of BNS is independent of their chirality [53]. Also, BNS offer tunable interplanar distance by intercalation or doping making them a strong candidate for application in hydrogen storage, mass manipulation, and targeted drug delivery [54][55][56][57].…”