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Budyka MF. Semiempirical study on the absorption spectra of the coronene-like molecular models of graphene quantum dots. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 207:1-5. [PMID: 30195180 DOI: 10.1016/j.saa.2018.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/14/2018] [Accepted: 09/02/2018] [Indexed: 06/08/2023]
Abstract
Polycyclic aromatic hydrocarbons of the general formula C6n2H6n (coronene family) were used as molecular models of graphene quantum dots (GQDs). Absorption spectra of the model compounds were calculated by ZINDO/S method. The S0 → S1 transition energy (E1) was found to decrease with n as E1 = 4.75 × n-0.633 eV. This transition is forbidden in symmetric compounds but 'switches on' upon symmetry breaking. The energy of the first bright optical peak (Ebr) was found to decrease with n as Ebr = 6.31 × n-0.6 eV. The data obtained corroborate the earlier finding that the size-independent optical properties of GQDs are determined by relatively small isolated sp2 clusters separated by sp3 (oxygen-contained) 'defects' rather than the whole (corrupted) graphene sheets; such nanoparticles actually are not quantum dots. GQDs of pure (without defects) graphene sheets with fully π-conjugated sp2 systems should exhibit size-dependent optical properties due to the quantum confinement effect.
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Affiliation(s)
- Mikhail F Budyka
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russian Federation.
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Hage FS, Hardcastle TP, Gjerding MN, Kepaptsoglou DM, Seabourne CR, Winther KT, Zan R, Amani JA, Hofsaess HC, Bangert U, Thygesen KS, Ramasse QM. Local Plasmon Engineering in Doped Graphene. ACS NANO 2018; 12:1837-1848. [PMID: 29369611 DOI: 10.1021/acsnano.7b08650] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Single-atom B or N substitutional doping in single-layer suspended graphene, realized by low-energy ion implantation, is shown to induce a dampening or enhancement of the characteristic interband π plasmon of graphene through a high-resolution electron energy loss spectroscopy study using scanning transmission electron microscopy. A relative 16% decrease or 20% increase in the π plasmon quality factor is attributed to the presence of a single substitutional B or N atom dopant, respectively. This modification is in both cases shown to be relatively localized, with data suggesting the plasmonic response tailoring can no longer be detected within experimental uncertainties beyond a distance of approximately 1 nm from the dopant. Ab initio calculations confirm the trends observed experimentally. Our results directly confirm the possibility of tailoring the plasmonic properties of graphene in the ultraviolet waveband at the atomic scale, a crucial step in the quest for utilizing graphene's properties toward the development of plasmonic and optoelectronic devices operating at ultraviolet frequencies.
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Affiliation(s)
| | - Trevor P Hardcastle
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, U.K
- School of Chemical and Process Engineering, University of Leeds , Leeds LS2 9JT, U.K
| | - Morten N Gjerding
- CAMD and Center for Nanostructured Graphene (CNG), Technical University of Denmark , Fysikvej 1, Building 307, 2800 Kgs. Lyngby, Denmark
| | - Demie M Kepaptsoglou
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, U.K
- York NanoCentre, University of York , Heslington, York YO10 5BR, U.K
| | - Che R Seabourne
- School of Chemical and Process Engineering, University of Leeds , Leeds LS2 9JT, U.K
| | - Kirsten T Winther
- CAMD and Center for Nanostructured Graphene (CNG), Technical University of Denmark , Fysikvej 1, Building 307, 2800 Kgs. Lyngby, Denmark
| | - Recep Zan
- Nanotechnology Application and Research Center, Niğde Omer Halisdemir University , Niğde 51000, Turkey
| | - Julian Alexander Amani
- II Physikalisches Institut, Georg-August-Universität Göttingen , Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Hans C Hofsaess
- II Physikalisches Institut, Georg-August-Universität Göttingen , Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Ursel Bangert
- Bernal Institute and Department of Physics, University of Limerick , Limerick, Ireland
| | - Kristian S Thygesen
- CAMD and Center for Nanostructured Graphene (CNG), Technical University of Denmark , Fysikvej 1, Building 307, 2800 Kgs. Lyngby, Denmark
| | - Quentin M Ramasse
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, U.K
- School of Chemical and Process Engineering, University of Leeds , Leeds LS2 9JT, U.K
- School of Physics, University of Leeds , Leeds LS2 9JT, U.K
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Agresti F, Barison S, Famengo A, Pagura C, Fedele L, Rossi S, Bobbo S, Rancan M, Fabrizio M. Surface oxidation of single wall carbon nanohorns for the production of surfactant free water-based colloids. J Colloid Interface Sci 2017; 514:528-533. [PMID: 29289735 DOI: 10.1016/j.jcis.2017.12.058] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/12/2017] [Accepted: 12/21/2017] [Indexed: 10/18/2022]
Abstract
In this work, powders of Single Wall Carbon Nanohorns (SWCNHs), a typical hydrophobic material, were oxidized with concentrated HNO3 with the aim of surface carboxylation and consequent improved hydrophilicity and dispersibility in polar solvents. Dynamic Light Scattering and ζ-potential measurements demonstrated that very stable colloidal suspensions of SWCNH in water were obtained in total absence of stabilizers. By properly optimizing the reaction parameters, the suspensions achieved stability even higher than colloids with similar composition but prepared with the use of surfactants. Surface damage and oxidation degree of SWCNHs were evaluated by SEM microscopy, Thermogravimetric Analysis, Residual Gas Analysis, XPS and UV-visible spectroscopy.
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Affiliation(s)
- Filippo Agresti
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
| | - Simona Barison
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy.
| | - Alessia Famengo
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
| | - Cesare Pagura
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
| | - Laura Fedele
- Institute of Construction Technologies (ITC), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
| | - Stefano Rossi
- Institute of Construction Technologies (ITC), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
| | - Sergio Bobbo
- Institute of Construction Technologies (ITC), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
| | - Marzio Rancan
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council of Italy (CNR), c/o Dept. Chemical Science, University of Padua, Via Marzolo 1, 35131 Padova, Italy
| | - Monica Fabrizio
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), National Research Council of Italy (CNR), Corso Stati Uniti 4, Padova, Italy
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Hu J, Shen M, Li Z, Li X, Liu G, Wang X, Kan C, Li Y. Dual-channel extraordinary ultraviolet transmission through an aluminum nanohole array. NANOTECHNOLOGY 2017; 28:215205. [PMID: 28358302 DOI: 10.1088/1361-6528/aa6a38] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Ultraviolet (UV) surface plasmon (SP) has distinct applications in UV filters, high-density optical storage, spectral enhancement, optical detectors, and nanolithography, which are closely related to plasmon-induced extraordinary optical transmission (EOT). However, such EOT in the UV region has not been the subject of detailed research. We report UV transmission based on theoretical research using the finite-difference time-domain method, by modulating the Al thickness, hole size, array periodicity, and SiO2 overlayer thickness. It is notable that we can obtain dual-channel UV transmission peaks with excellent qualities such as high transmissivity, zero cross-talk, narrow bandwidth, and perfect symmetry, by optimizing the parameters. The UV transmission peaks have been discovered to non-monotonously shift with increasing hole size. Although array periodicity has great influence on the transmission peak position, the peak energy in the UV region is much less than the value predicted by the well-known periodicity-related surface plasmon polariton (SPP) wavelength equation; the energy discrepancy in the UV region can reach above 20%, which is much larger than the value (typically 4%) in the visible-infrared region. Furthermore, the SiO2 overlayer may significantly modify the transmission properties. The Al nanohole arrays have also been found to exhibit distinct multi-band UV electric field enhancement properties with special interface effect and size effect. Such extraordinary dual-channel UV transmission with zero cross-talk, based on a very simple Al nanohole array, has promising application in dual-channel UV filters, high-density optical storage, and plasmon-enhanced fluorescence/Raman spectroscopy, which generally involves two wavebands (writing/reading storage or exciting/emission wavelengths). This study is expected to broaden our fundamental understanding of the UV EOT phenomenon, and provide references for experimental research and application of deep-UV and near-UV-related dual-band plasmonic devices.
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Affiliation(s)
- Jinlian Hu
- School of Materials Science and Engineering, and Anhui Key Laboratory of Metal Materials and Processing, Anhui University of Technology, Ma-An-Shan, Anhui 243002, People's Republic of China
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