We demonstrate the fabrication of nanoperforated graphene materials with sub-20-nm features using cylinder-forming diblock copolymer templates across >1 mm(2) areas. Hexagonal arrays of holes are etched into graphene membranes, and the remaining constrictions between holes interconnect forming a honeycomb structure. Quantum confinement, disorder, and localization effects modulate the electronic structure, opening an effective energy gap of 100 meV in the nanopatterned material. The field-effect conductivity can be modulated by 40x (200x) at room temperature (T = 105 K) as a result. A room temperature hole mobility of 1 cm(2) V(-1) s(-1) was measured in the fabricated nanoperforated graphene field effect transistors. This scalable strategy for modulating the electronic structure of graphene is expected to facilitate applications of graphene in electronics, optoelectronics, and sensing.
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http://dx.doi.org/10.1021/nl9032318 | DOI Listing |
Nanomaterials (Basel)
September 2024
Department of Science and Engineering of Matter, Environment and Urban Planning, Marche Polytechnic University, Via Brecce Bianche, 60131 Ancona, Italy.
Nanotechnology
December 2022
Foundation of Research and Technology Hellas, Institute of Chemical Engineering Sciences, PO Box 1414, GR-26504 Patras, Greece.
The formation of nano-pores in graphene crystal structure is alternative way to engineer its electronic properties, chemical reactivity, and surface interactions, enabling applications in technological fields such as sensing, energy and separation. The past few years, nano-perforation of graphene sheets has been accomplished by a variety of different methods suffering mainly from poor scalability and cost efficiency issues. In this work, we introduce an experimental protocol to engineer nanometer scale pores in CVD graphene membranes under ambient conditions, using low power ultra-short laser pulses and overcoming the drawbacks of other perforation techniques.
View Article and Find Full Text PDFNanotechnology
January 2017
National Institute for Research and Development in Microtechnology (IMT), PO Box 38-160, 023573 Bucharest, Romania.
We report the batch fabrication of graphene field-effect-transistors (GFETs) with nanoperforated graphene as channel. The transistors were cut and encapsulated. The encapsulated GFETs display saturation regions that can be tuned by modifying the top gate voltage, and have on/off ratios of at least 2 × 10 at room temperature and at small drain and gate voltages.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2014
Department of Materials Science and Engineering, University of Wisconsin-Madison, Wisconsin 53706, United States.
In this work, we demonstrate that a preassembled block copolymer (BCP) thin film can be floated, transferred, and utilized to effectively nanopattern unconventional substrates. As target substrates, we chose Cu foil and graphene/Cu foil since they cannot be nanopatterned via conventional processes due to the high surface roughness and susceptibility to harsh processing chemicals and etchants. Perpendicular hexagonal PMMA cylinder arrays in diblock copolymer poly(styrene-block-methyl methacrylate) [P(S-b-MMA)] thin films were preassembled on sacrificial SiO2/Si substrates.
View Article and Find Full Text PDFSmall
August 2013
Centre of Excellence in Solar Energy, National Chemical Laboratory-CSIR-NCL, Dr. Homi Bhabha Road, Pune 411008, India & Network Institute of Solar Energy-CSIR-NISE, New Delhi, India.
High performance is reported for a symmetric ultracapacitor (UC) cell made up of hierarchically perforated graphene nanosheets (HPGN) as an electrode material with excellent values of energy density (68.43 Wh kg⁻¹) and power density (36.31 kW kg⁻¹).
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