Defect/oxygen assisted direct write technique for nanopatterning graphene

Abstract

High resolution nanopatterning of graphene enables manipulation of electronic, optical and sensing properties of graphene. In this work we present a straightforward technique that does not require any lithographic mask to etch nanopatterns into graphene. The technique relies on the damaged graphene to be etched selectively in an oxygen rich environment with respect to non-damaged graphene. Sub-40 nm features were etched into graphene by selectively exposing it to a 100 keV electron beam and then etching the damaged areas away in a conventional oven. Raman spectroscopy was used to evaluate the extent of damage induced by the electron beam as well as the effects of the selective oxidative etching on the remaining graphene.

Novel Hybrid Conductor of Irregularly Patterned Graphene Mesh and Silver Nanowire Networks

“…In order to make the hybrid conductor of Ag NW-GP with high optical and electrical properties, there has been big progress in GP mesh engineering by tailoring its pattern into predefined shapes, position, and sizes at atomic scale mainly through (i) vacuum processes of He-ion/electron beam lithography, O 2 plasma etching, nanoimprint lithography, catalytic passivation, catalytic etching and hot embossing imprinting [13][14][15][16][17][18][19][20], and (ii) non-vacuum approaches of laser-assisted transfer printing, laser ablation, micro-molding, and masking layer based mesh-patterning [21][22][23][24][25][26][27].…”

“…First, most GP patterning approaches require complicated, low durability and expensive lithographic steps, instruments, and materials, leading to lacked scalability and low production speed of GP meshes [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Specifically, the as-mentioned patterning process for GP involves multiple steps of complicated template/mask preparation (mask lithography), lifting/stamping of patterned GP onto a substrate, photoresist (PR) developing, etching, PR/mask removal, and laser ablation [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Second, the optical interference effect (i.e., Moire phenomenon) can be observed in the display image because of a constructive and destructive interferences by regularly arrayed voids in GP mesh [34,35].…”

Thermal Stability of Single-layer Graphene Subjected to Confocal Laser Heating Investigated by Using in situ Anti-Stokes and Stokes Raman Spectroscopy

“…33 It implies that the structural disorder was induced by not only the thermal induced defects but also by bonded oxygen, because oxygen can bond to SLG defects and would be much easier via heating treatment. 34,35 Moreover, the doping level could be monitored by considering the inverse relation of I(2D)/I(G). 28 Consequently, according to the reduced I(2D)/I(G) in pace with the increasing I(D)/I(G) in Fig.…”

Batch fabrication of nanopatterned graphene devices via nanoimprint lithography

“…These stray electrons can not only cause unwanted proximity effects and pattern distortion but also cause direct damage to the graphene at electron energies well below the 85 keV threshold for knock-on damage. 21,22 The most frequently used and studied positive electron beam resist in graphene research, PMMA, is not only chain-scissioned but also cross-linked under electron beam irradiation, which would make residues less soluble and ultimately increase doping levels compared to NIL. Moreover, the carrier mobility can also be reduced in patterned areas, 23 and since the patterns in samples such as ours are fairly dense, we attribute the low level of doping and defect generation to the avoidance of electron beam irradiation.…”