We fabricated graphene pnp devices, by embedding pre-defined local gates in an oxidized surface layer of a silicon substrate. With neither deposition of dielectric material on the graphene nor electron-beam irradiation, we obtained high-quality graphene pnp devices without degradation of the carrier mobility even in the local-gate region. The corresponding increased mean free path leads to the observation of ballistic and phase-coherent transport across a local gate 130 nm wide, which is about an order of magnitude wider than reported previously. Furthermore, in our scheme, we demonstrated independent control of the carrier density in the local-gate region, with a conductance map very much distinct from those of top-gated devices. This was caused by the electric field arising from the global back gate being strongly screened by the embedded local gate. Our scheme allows the realization of ideal multipolar graphene junctions with ballistic carrier transport.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1088/0957-4484/22/41/415203 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Superior selectivity for efficiently reductive degradation of hydrophobic organic pollutants in strongly competitive systems.
J Hazard Mater
December 2024
Department of Civil, Construction and Environmental Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
Highly toxic halo-/nitro-substituted organics, often in low concentrations and with high hydrophobicity, make it difficult to obtain electrons for reduction when strongly electron-competing substances (e.g., O, H/HO, NO) coexist.
View Article and Find Full Text PDFAdvances of the Holographic Technique to Test the Basic Properties of the Thin-Film Organics: Refractivity Change and Novel Mechanism of the Nonlinear Attenuation Prediction.
Polymers (Basel)
September 2024
Joint Stock Company Scientific and Production Corporation S.I. Vavilov State Optical Institute, Babushkina Str. dom 36, Korpus 1, St. Petersburg 192171, Russia.
A large number of the thin-film organic structures (polyimides, 2-cyclooctylarnino-5-nitropyridine, N-(4-nitrophenyl)-(L)-prolinol, 2-(n-Prolinol)-5-nitropyridine) sensitized with the different types of the nano-objects (fullerenes, carbon nanotubes, quantum dots, shungites, reduced graphene oxides) are presented, which are studied using the holographic technique under the Raman-Nath diffraction conditions. Pulsed laser irradiation testing of these materials predicts a dramatic increase of the laser-induced refractive index, which is in several orders of the magnitude greater compared to pure materials. The estimated nonlinear refraction coefficients and the cubic nonlinearities for the materials studied are close to or larger than those known for volumetric inorganic crystals.
View Article and Find Full Text PDFSynthesis of polymeric 2D-graphitic carbon nitride (g-CN) nanosheets for sustainable photodegradation of organic pollutants.
Heliyon
July 2024
Department of Chemistry, Ghani Khan Choudhury Institute of Engineering and Technology (GKCIET), Narayanpur, Malda, 732141, India.
A superficial, one step thermal polycondensation method has been employed for the manifestation of graphene like graphitic carbon nitride (g-CN) catalyst. The as synthesized g-CN was well characterized by SEM and EDAX analysis, XRD, ATR-IR, FTIR, Fluorescence spectroscopy, Raman spectroscopy and UV-Visible spectroscopy which provide structural, morphological assemblage relating to the structure of g-CN. The g-CN showed that an outstanding photochemical stability, morphology, conductive carbon framework and superior photocatalytic activity.
View Article and Find Full Text PDFTwo-Dimensional Nickel Porphyrinic Metal-Organic Framework-Modified Electrode for Electrochemical Sensing.
Langmuir
February 2024
Research Center for Intelligent and Wearable Technology, College of Textiles and Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China.
Due to their highly exposed active sites and high aspect ratio caused by their substantial lateral dimension and thin thickness, two-dimensional (2D) metal-organic framework (MOF) nanosheets are currently considered a potential hybrid material for electrochemical sensing. Herein, we present a nickel-based porphyrinic MOF nanosheet as a versatile and robust platform with an enhanced electrochemical detection performance. It is important to note that the nickel porphyrin ligand reacted with Cu(NO)·3HO in a solvothermal process, with polyvinylpyrrolidone (PVP) acting as the surfactant to control the anisotropic development of creating a 2D Cu-TCPP(Ni) MOF nanosheet structure.
View Article and Find Full Text PDFIn Situ Rapid Fabrication of Graphene-Copper Heterojunctions Using Fiber Laser Direct Writing.
ACS Appl Mater Interfaces
December 2023
Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Multifunctional three-dimensional heterostructures for flexible electronics have gained significant attention due to their distinctive structural formability and superior electronic and optoelectronic properties. Nevertheless, conventional fabrication techniques have yet to be optimized for flexible substrates. In this study, a straightforward fiber laser direct writing (FLDW) process is demonstrated for the simultaneous fabrication of diodes (PN junctions) and bipolar junction transistors (BJTs) on flexible polyimide substrates, which is realized through the deposition of multifunctional p- or n-type copper oxide films (CuO) and p- or n-type porous laser-reduced graphene oxide films (LrGO) using fiber laser ablation and deposition.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!