RETRACTED ARTICLE: Large-Area Semiconducting Graphene Nanomesh Tailored by Interferometric Lithography

Abstract

Graphene nanostructures are attracting a great deal of interest because of newly emerging properties originating from quantum confinement effects. We report on using interferometric lithography to fabricate uniform, chip-scale, semiconducting graphene nanomesh (GNM) with sub-10 nm neck widths (smallest edge-to-edge distance between two nanoholes). This approach is based on fast, low-cost, and high-yield lithographic technologies and demonstrates the feasibility of cost-effective development of large-scale semiconducting graphene sheets and devices. The GNM is estimated to have a room temperature energy bandgap of ~30 meV. Raman studies showed that the G band of the GNM experiences a blue shift and broadening compared to pristine graphene, a change which was attributed to quantum confinement and localization effects. A single-layer GNM field effect transistor exhibited promising drive current of ~3.9 μA/μm and ON/OFF current ratios of ~35 at room temperature. The ON/OFF current ratio of the GNM-device displayed distinct temperature dependence with about 24-fold enhancement at 77 K.

Strain engineering in monolayer WS2, MoS2, and the WS2/MoS2 heterostructure

“…Tremendous efforts were made to open a bandgap in graphene, but the progress remains slow. [6][7][8][9][10] Transition metal dichalcogenides (TMDs), being also layered materials with an S-M-S (M ¼ Mo, W) sandwich structure bonded by van der Waals forces, recently were investigated extensively as a class of alternative two-dimensional materials. 11,12 This is largely due to the fact that monolayer TMDs have direct bandgaps corresponding to the region of visible light, which indicates the potential for applications in optoelectronic devices.…”

A seamless-pitched graphene nanoribbon field effect transistor

“…Son et al [16] designedsub-10 nm graphene nanoribbon array FETs fabricated through block copolymer lithography. In [17], Kazemi et al usedinterferometric lithography for making large-area semiconducting graphene nanomesh. Authors of [18] proposed temperature-triggered chemical switching growth of in-plane and vertically-stacked graphene-boron nitride heterostructures.…”

Nanoperforated graphene with alternating gap switching for optical applications

“…Due to the effective tunability of intrinsic graphene bang gap, these porous graphene structures possess potential applications in spintronics, 12,14 thermoelectronics, 23,27 waveguiding devices, 29,31 and transistors. [15][16][17][18][19]32 GNM based field-effect transistors perform some improved electronic properties than sliced graphene nanoribbon (GNR) devices, 16 it could deliver 100 times higher drive currents, and demonstrated comparable tunable ON/OFF ratios than similar individual GNR devices. Thus the semimetallic to semiconducting state transition in porous graphene structures plays vital role in pursuing favorable semiconductor devices.…”

“…The production of porous graphene structures have been obtained utilizing various techniques, comprising the organic building blocks, etching, and template assisted method. [15][16][17][18][19][20]32 The punched graphene films with sub-nanometer holes and narrow neck width are successfully fabricated. Furthermore, the copolymer lithography 16 and imprint lithography 17 lead to sub-10 nanometer neck width, which can meet the requirements for decreasing feature size and opening a band gap in graphene.…”

“…Extensive approaches have been used to tackle with this problem including dimensionality reduction tailoring, [6][7] surface modification, 8 heteroatom doping, 9 layered stacking, 10 and exerted to external potential. 11 In addition to those schemes, however recently, the topic about graphene superlattice with nanoholes, [12][13][14] also dubbed graphene nanomesh (GNM), [15][16][17][18][19][20][21][22][23] or graphene antidote lattice (GAL), [24][25][26][27][28][29][30][31] attracts substantial research interest since a non-vanishing gap is introduced in certain unique structures. Due to the effective tunability of intrinsic graphene bang gap, these porous graphene structures possess potential applications in spintronics, 12,14 thermoelectronics, 23,27 waveguiding devices, 29,31 and transistors.…”