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Chesnyak V, Cuxart MG, Baranowski D, Seufert K, Cojocariu I, Jugovac M, Feyer V, Auwärter W. Stripe-Like hBN Monolayer Template for Self-Assembly and Alignment of Pentacene Molecules. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304803. [PMID: 37821403 DOI: 10.1002/smll.202304803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/28/2023] [Indexed: 10/13/2023]
Abstract
Metallic surfaces with unidirectional anisotropy are often used to guide the self-assembly of organic molecules along a particular direction. Such supports thus offer an avenue for the fabrication of hybrid organic-metal interfaces with tailored morphology and precise elemental composition. Nonetheless, such control often comes at the expense of detrimental interfacial interactions that might quench the pristine properties of molecules. Here, hexagonal boron nitride grown on Ir(100) is introduced as a robust platform with several coexisting 1D stripe-like moiré superstructures that effectively guide unidirectional self-assemblies of pentacene molecules, concomitantly preserving their pristine electronic properties. In particular, highly-aligned longitudinal arrays of equally-oriented molecules are formed along two perpendicular directions, as demonstrated by comprehensive scanning tunneling microscopy and photoemission characterization performed at the local and non-local scale, respectively. The functionality of the template is demonstrated by photoemission tomography, a surface-averaging technique requiring a high degree of orientational order of the probed molecules. The successful identification of pentacene's pristine frontier orbitals underlines that the template induces excellent long-range molecular ordering via weak interactions, preventing charge transfer.
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Affiliation(s)
- Valeria Chesnyak
- Physics Department, TUM School of Natural Sciences, Technical University of Munich, 85747, Garching, Germany
- Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, Trieste, 34127, Italy
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, S.S. 14 km 163.5 in AREA Science Park, Basovizza, Trieste, 34149, Italy
| | - Marc G Cuxart
- Physics Department, TUM School of Natural Sciences, Technical University of Munich, 85747, Garching, Germany
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049, Madrid, Spain
| | - Daniel Baranowski
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Knud Seufert
- Physics Department, TUM School of Natural Sciences, Technical University of Munich, 85747, Garching, Germany
| | - Iulia Cojocariu
- Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, Trieste, 34127, Italy
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
- Elettra-Sincrotrone, S.C.p.A. S.S 14 - km 163.5, Trieste, 34149, Italy
| | - Matteo Jugovac
- Elettra-Sincrotrone, S.C.p.A. S.S 14 - km 163.5, Trieste, 34149, Italy
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
- Fakultät für Physik and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, 47048, Duisburg, Germany
| | - Willi Auwärter
- Physics Department, TUM School of Natural Sciences, Technical University of Munich, 85747, Garching, Germany
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Yang D, Ma F, Bian X, Xia Q, Xu K, Hu T. The growth of epitaxial graphene on SiC and its metal intercalation: a review. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:173003. [PMID: 38237180 DOI: 10.1088/1361-648x/ad201a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 01/18/2024] [Indexed: 02/02/2024]
Abstract
High-quality epitaxial graphene (EG) on SiC is crucial to high-performance electronic devices due to the good compatibility with Si-based semiconductor technology. Metal intercalation has been considered as a basic technology to modify EG on SiC. In the past ten years, there have been extensive research activities on the structural evolution during EG fabrication, characterization of the atomic structure and electronic states of EG, optimization of the fabrication process, as well as modification of EG by metal intercalation. In this perspective, the developments and breakthroughs in recent years are summarized and future expectations are discussed. A good understanding of the growth mechanism of EG and subsequent metal intercalation effects is fundamentally important.
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Affiliation(s)
- Dong Yang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
- Department of Physics, School of Biomedical Information and Engineering, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
| | - Fei Ma
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China
| | - Xianglong Bian
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
| | - Qianfeng Xia
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
| | - Kewei Xu
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China
| | - Tingwei Hu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and The Second Affiliated Hospital, Hainan Medical University, Haikou, Hainan 571199, People's Republic of China
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China
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Balle D, Schedel C, Chassé T, Peisert H. Interface properties of CoPc and CoPcF 16 on graphene/nickel: influence of germanium intercalation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:174004. [PMID: 30695754 DOI: 10.1088/1361-648x/ab028f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Photoelectron spectroscopy was used to investigate electronic interface properties and interactions of the organic semiconductors CoPc and CoPcF16 on graphene/nickel based substrates. Additional focus was put on the influence of germanium intercalation of graphene/nickel. The presented results demonstrate that germanium can decouple graphene from nickel and in this manner restore its buffer layer properties. No charge transfer from the substrate to the organic layer is observed in the germanium intercalated case, while interface related peaks in the Co 2p core level spectra indicate such charge transfer on graphene/nickel. Strong interface dipoles are found for CoPcF16 on graphene/nickel and on germanium intercalated graphene/nickel. Fluorine Auger parameters have been measured, and the results provide evidence for polarization and charge transfer screening effects of different amounts at the unlike film-substrate interfaces. The various contributions to the observed shifts are discussed.
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Affiliation(s)
- David Balle
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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Fedorov AV, Yashina LV, Vilkov OY, Laubschat C, Vyalikh DV, Usachov DY. Spin-polarized Fermi surface, hole-doping and band gap in graphene with boron impurities. NANOSCALE 2018; 10:22810-22817. [PMID: 30488051 DOI: 10.1039/c8nr08339h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Embedding foreign atoms in graphene and interchanging the underlying substrate are proved to be efficient methods for manipulating the properties of graphene. Combining ARPES experiments with DFT calculations we show that boron-doped graphene (B-graphene) grown on a Co(0001) substrate by chemical vapor deposition (CVD) becomes hole doped and its Fermi surface near the K-point reveals strongly spin-polarized states. The latter stems from the spin-polarized mini Dirac cone that is an intrinsic two-dimensional feature of the graphene/Co(0001) interface and is formed by a mixture of C 2pz and Co 3d states. Since the CVD method allows the achievement of up to 20 at% of incorporated B atoms, this provides a certain flexibility for handling the spin-polarized properties of the system. We also show that the bonding of the B-graphene layer to the Co(0001) substrate can be released by intercalation of Li into the interface. This allows the exploration of the doping effect in detail. Finally, our ARPES data indicate a gap opening in the Dirac cone as a result of the highly unbalanced boron concentrations in the two graphene sublattices.
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Affiliation(s)
- Alexander V Fedorov
- St. Petersburg State University, 7/9 Universitetskaya Nab., St Petersburg 199034, Russia. and IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany
| | - Lada V Yashina
- M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 199991 Moscow, Russia
| | - Oleg Yu Vilkov
- St. Petersburg State University, 7/9 Universitetskaya Nab., St Petersburg 199034, Russia.
| | - Clemens Laubschat
- Institute of Solid State and Materials Physics, Technische Universität Dresden, 01062 Dresden, Germany
| | - Denis V Vyalikh
- Donostia International Physics Center (DIPC), Departamento de Fisica de Materiales and CFM-MPC UPV/EHU, 20080 San Sebastian, Spain and IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Dmitry Yu Usachov
- St. Petersburg State University, 7/9 Universitetskaya Nab., St Petersburg 199034, Russia.
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Liu X, Hersam MC. Interface Characterization and Control of 2D Materials and Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801586. [PMID: 30039558 DOI: 10.1002/adma.201801586] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 04/09/2018] [Indexed: 05/28/2023]
Abstract
2D materials and heterostructures have attracted significant attention for a variety of nanoelectronic and optoelectronic applications. At the atomically thin limit, the material characteristics and functionalities are dominated by surface chemistry and interface coupling. Therefore, methods for comprehensively characterizing and precisely controlling surfaces and interfaces are required to realize the full technological potential of 2D materials. Here, the surface and interface properties that govern the performance of 2D materials are introduced. Then the experimental approaches that resolve surface and interface phenomena down to the atomic scale, as well as strategies that allow tuning and optimization of interfacial interactions in van der Waals heterostructures, are systematically reviewed. Finally, a future outlook that delineates the remaining challenges and opportunities for 2D material interface characterization and control is presented.
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Affiliation(s)
- Xiaolong Liu
- Applied Physics Graduate Program, Northwestern University, 2220 Campus Drive, Evanston, IL, 60208-3108, USA
| | - Mark C Hersam
- Applied Physics Graduate Program, Northwestern University, 2220 Campus Drive, Evanston, IL, 60208-3108, USA
- Department of Materials Science and Engineering, Department of Chemistry, Department of Medicine, Department of Electrical Engineering and Computer Science, Northwestern University, 2220 Campus Drive, Evanston, IL, 60208-3108, USA
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