A contactless single-step process for simultaneous nanoscale patterning and cleaning of large-area graphene

Abstract

The capability to structure two-dimensional materials at the nanoscale with customizable patterns and over large areas is critical for a number of emerging applications, from nanoelectronics to 2D photonic metasurfaces. However, current technologies, such as photo- and electron beam lithography, often employing masking layers, can significantly contaminate the materials. Large-area CVD-grown graphene is known to have non-ideal properties already due to surface contamination resulting from the transferring process. Additional contamination through the lithographic process might thus reduce the performance of any device based on the structured graphene. Here, we demonstrate a contactless chemical-free approach for simultaneous patterning and cleaning of self-supporting graphene membranes in a single step. Using energetic ions passing through a suspended mask with pre-defined nanopatterns, we deterministically structure graphene with demonstrated feature size of 15 nm, approaching the performance of small-area focused ion beam techniques and extreme UV lithography. Our approach, however, requires only a broad beam, no nanoscale beam positioning and enables large area patterning of 2D-materials. Simultaneously, in regions surrounding the exposed areas, contaminations commonly observed on as-grown graphene targets, are effectively removed. This cleaning mechanism is attributed to coupling of surface diffusion and sputtering effects of adsorbed surface contaminants. For applications using 2D-materials, this simultaneous patterning and cleaning mechanism may become essential for preparing the nanostructured materials with improved cleanliness and hence, quality.

Status and Prospect of Two-Dimensional Materials in Electrolytes for All-Solid-State Lithium Batteries

“…However, the majority of composite SSEs consisting of polymers and 2D inert fillers have ionic conductivity under 10 –4 S cm –1 at room temperature due to the limitations of polymers with low ionic conductivity of 10 –6 ∼10 –8 S cm –1 and the insulation of 2DMs for Li + . Therefore, in addition to the inorganic inert fillers discussed above, active 2DMs have also been gradually exploited and used as electrolyte components to individually transport Li + in the last two years. ,− …”

Modification of the Photochromic Properties of Oxygen-Containing Yttrium Hydride by Irradiation with keV and MeV Ions

“…18 Energetic ions traversing a material transfer energy to its nuclear and electron systems, leading to the formation of crystal defects 19 or their annealing, depending on which process prevails at the given irradiation conditions. 20 For example, ion irradiation was employed for graphene nanopatterning 21 and to improve the hydrogen evolution reaction performance of MoS 2 . 22 In this work, we irradiate ∼300 nm thick photochromic YHO thin films with keV and MeV ions.…”