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Krajňák T, Stará V, Procházka P, Planer J, Skála T, Blatnik M, Čechal J. Robust Dipolar Layers between Organic Semiconductors and Silver for Energy-Level Alignment. ACS APPLIED MATERIALS & INTERFACES 2024; 16:18099-18111. [PMID: 38551398 PMCID: PMC11009919 DOI: 10.1021/acsami.3c18697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/13/2024] [Accepted: 03/13/2024] [Indexed: 04/12/2024]
Abstract
The interface between a metal electrode and an organic semiconductor (OS) layer has a defining role in the properties of the resulting device. To obtain the desired performance, interlayers are introduced to modify the adhesion and growth of OS and enhance the efficiency of charge transport through the interface. However, the employed interlayers face common challenges, including a lack of electric dipoles to tune the mutual position of energy levels, being too thick for efficient electronic transport, or being prone to intermixing with subsequently deposited OS layers. Here, we show that monolayers of 1,3,5-tris(4-carboxyphenyl)benzene (BTB) with fully deprotonated carboxyl groups on silver substrates form a compact layer resistant to intermixing while capable of mediating energy-level alignment and showing a large insensitivity to substrate termination. Employing a combination of surface-sensitive techniques, i.e., low-energy electron microscopy and diffraction, X-ray photoelectron spectroscopy, and scanning tunneling microscopy, we have comprehensively characterized the compact layer and proven its robustness against mixing with the subsequently deposited organic semiconductor layer. Density functional theory calculations show that the robustness arises from a strong interaction of carboxylate groups with the Ag surface, and thus, the BTB in the first layer is energetically favored. Synchrotron radiation photoelectron spectroscopy shows that this layer displays considerable electrical dipoles that can be utilized for work function engineering and electronic alignment of molecular frontier orbitals with respect to the substrate Fermi level. Our work thus provides a widely applicable molecular interlayer and general insights necessary for engineering of charge injection layers for efficient organic electronics.
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Affiliation(s)
- Tomáš Krajňák
- CEITEC—Central
European Institute of Technology, Brno University
of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Veronika Stará
- CEITEC—Central
European Institute of Technology, Brno University
of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Pavel Procházka
- CEITEC—Central
European Institute of Technology, Brno University
of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Jakub Planer
- CEITEC—Central
European Institute of Technology, Brno University
of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Tomáš Skála
- Department
of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague 8, Czech Republic
| | - Matthias Blatnik
- CEITEC—Central
European Institute of Technology, Brno University
of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Jan Čechal
- CEITEC—Central
European Institute of Technology, Brno University
of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
- Institute
of Physical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic
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Karner C, Bianchi E. Anisotropic functionalized platelets: percolation, porosity and network properties. NANOSCALE ADVANCES 2024; 6:443-457. [PMID: 38235098 PMCID: PMC10790971 DOI: 10.1039/d3na00621b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024]
Abstract
Anisotropic functionalized platelets are able to model the assembly behaviour of molecular systems in two dimensions thanks to the unique combination of steric and bonding constraints. The assembly scenarios can vary from open to close-packed crystals, finite clusters and chains, according to the features of the imposed constraints. In this work, we focus on the assembly of equilibrium networks. These networks can be seen as disordered, porous monolayers and can be of interest for instance in nano-filtration and optical applications. We investigate the formation and properties of two dimensional networks from shape anisotropic colloids functionalized with four patches. We characterize the connectivity properties, the typical local bonding motives, as well as the geometric features of the emerging networks for a large variety of different systems. Our results show that networks of shape anisotropic colloids assemble into highly versatile network topologies, that may be utilized for applications at the nanoscale.
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Affiliation(s)
- Carina Karner
- Institut für Theoretische Physik, TU Wien Wiedner Hauptstraße 8-10 A-1040 Wien Austria
| | - Emanuela Bianchi
- Institut für Theoretische Physik, TU Wien Wiedner Hauptstraße 8-10 A-1040 Wien Austria
- CNR-ISC, Uos Sapienza Piazzale A. Moro 2 00185 Roma Italy
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3
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Procházka P, Čechal J. Visualization of molecular stacking using low-energy electron microscopy. Ultramicroscopy 2023; 253:113799. [PMID: 37364403 DOI: 10.1016/j.ultramic.2023.113799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 05/24/2023] [Accepted: 06/19/2023] [Indexed: 06/28/2023]
Abstract
The design of metal-organic interfaces with atomic precision enables the fabrication of highly efficient devices with tailored functionality. The possibility of fast and reliable analysis of molecular stacking order at the interface is of crucial importance, as the interfacial stacking order of molecules directly influences the quality and functionality of fabricated organic-based devices. Dark-field (DF) imaging using Low-Energy Electron Microscopy (LEEM) allows the visualization of areas with a specific structure or symmetry. However, distinguishing layers with different stacking orders featuring the same diffraction patterns becomes more complicated. Here we show that the top layer shift in organic molecular bilayers induces measurable differences in spot intensities of respective diffraction patterns that can be visualized in DF images. Scanning Tunneling Microscopy (STM) imaging of molecular bilayers allowed us to measure the shift directly and compare it with the diffraction data. We also provide a conceptual diffraction model based on the electron path differences, which qualitatively explains the observed phenomenon.
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Affiliation(s)
- Pavel Procházka
- CEITEC - Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czechia.
| | - Jan Čechal
- CEITEC - Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czechia; Institute of Physical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czechia
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4
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Lu J, Nieckarz D, Jiang H, Zhu Z, Yan Y, Zheng F, Rżysko W, Lisiecki J, Szabelski P, Sun Q. Order-Disorder Transition of Two-Dimensional Molecular Networks through a Stoichiometric Design. ACS NANO 2023; 17:20194-20202. [PMID: 37788293 DOI: 10.1021/acsnano.3c05945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Materials with disordered structures may exhibit interesting properties. Metal-organic frameworks (MOFs) are a class of hybrid materials composed of metal nodes and coordinating organic linkers. Recently, there has been growing interest in MOFs with structural disorder and the investigations of amorphous structures on surfaces. Herein, we demonstrate a bottom-up method to construct disordered molecular networks on metal surfaces by selecting two organic molecule linkers with the same symmetry but different sizes for preparing two-component samples with different stoichiometric ratios. The amorphous networks are directly imaged by scanning tunneling microscopy under ultrahigh vacuum with a submolecular resolution, allowing us to quantify its degree of disorder and other structural properties. Furthermore, we resort to molecular dynamics simulations to understand the formation of the amorphous metal-organic networks. The results may advance our understanding of the mechanism of formation of monolayer molecular networks with structural disorders, facilitating the design and exploration of amorphous MOF materials with intriguing properties.
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Affiliation(s)
- Jiayi Lu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Damian Nieckarz
- Department of Theoretical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, 20-031 Lublin, Poland
| | - Hao Jiang
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Zhiwen Zhu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yuyi Yan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Fengru Zheng
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Wojciech Rżysko
- Department of Theoretical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, 20-031 Lublin, Poland
| | - Jakub Lisiecki
- Department of Theoretical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, 20-031 Lublin, Poland
| | - Paweł Szabelski
- Department of Theoretical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, 20-031 Lublin, Poland
| | - Qiang Sun
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
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Shi J, Li Z, Lin T, Shi Z. Successive Deprotonation Steering the Structural Evolution of Supramolecular Assemblies on Ag(111). MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123876. [PMID: 35744999 PMCID: PMC9231327 DOI: 10.3390/molecules27123876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022]
Abstract
In this study, we demonstrate the structural evolution of a two-dimensional (2D) supramolecular assembly system, which is steered by the thermally activated deprotonation of the primary organic building blocks on a Ag(111) surface. Scanning tunneling microscopy revealed that a variety of structures, featuring distinct structural, chiral, and intermolecular bonding characters, emerged with the gradual thermal treatments. According to our structural analysis, in combination with density function theory calculations, the structural evolution can be attributed to the successive deprotonation of the organic building blocks due to the inductive effect. Our finding offers a facile strategy towards controlling the supramolecular assembly pathways and provides a comprehensive understanding of the 2D crystal engineering on surfaces.
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Affiliation(s)
- Jiwei Shi
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China;
| | - Zhanbo Li
- College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, China;
| | - Tao Lin
- College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, China;
- Correspondence: (T.L.); (Z.S.)
| | - Ziliang Shi
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China;
- Correspondence: (T.L.); (Z.S.)
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Chen H, Voigt L, Kubus M, Mihrin D, Mossin S, Larsen RW, Kegnæs S, Piligkos S, Pedersen KS. Magnetic Archimedean Tessellations in Metal-Organic Frameworks. J Am Chem Soc 2021; 143:14041-14045. [PMID: 34374526 DOI: 10.1021/jacs.1c05057] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The self-assembly of lanthanide ions with ditopic organic spacers results in the formation of complex tiling patterns that mimic the structural motifs of quasi-periodic 2D materials. The linking of trans-{LnI2}+ nodes (Ln = Gd, Dy) by both closed-shell and anion radicals of 4,4'-bipyridine affords rare examples of Archimedean tessellations in a metal-organic framework. We furthermore demonstrate the occurrence of sizable magnetic exchange interactions and slow relaxation of magnetization behavior in a complex tessellation pattern. The implementation of Archimedean tessellations in lanthanide(III) coordination solids couriers a strategy to design elusive quasi-periodic metal-organic frameworks with inimitable magnetic properties.
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Affiliation(s)
- Hua Chen
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Laura Voigt
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Mariusz Kubus
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Dmytro Mihrin
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Susanne Mossin
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - René W Larsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Søren Kegnæs
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Stergios Piligkos
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Kasper S Pedersen
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
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Crasto de Lima F, Fazzio A. Emergent quasiparticles in Euclidean tilings. NANOSCALE 2021; 13:5270-5274. [PMID: 33662069 DOI: 10.1039/d0nr08908g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A material's geometric structure is a fundamental part of its properties. The honeycomb geometry of graphene is responsible for its Dirac cone, while kagome and Lieb lattices host flat bands and pseudospin-1 Dirac dispersion. These features seem to be particular to a few 2D systems rather than a common occurrence. Given this correlation between structure and properties, exploring new geometries can lead to unexplored states and phenomena. Kepler is the pioneer of the mathematical tiling theory, describing ways of filling the Euclidean plane with geometric forms in his book Harmonices Mundi. In this article, we characterize 1255 lattices composed of k-uniform tiling of the Euclidean plane and unveil their intrinsic properties; this class of arranged tiles presents high-degeneracy points, exotic quasiparticles and flat bands as common features. Here, we present a guide for the experimental interpretation and prediction of new 2D systems.
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Affiliation(s)
- F Crasto de Lima
- Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970, Campinas, SP, Brazil.
| | - A Fazzio
- Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970, Campinas, SP, Brazil.
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Procházka P, Gosalvez MA, Kormoš L, de la Torre B, Gallardo A, Alberdi-Rodriguez J, Chutora T, Makoveev AO, Shahsavar A, Arnau A, Jelínek P, Čechal J. Multiscale Analysis of Phase Transformations in Self-Assembled Layers of 4,4'-Biphenyl Dicarboxylic Acid on the Ag(001) Surface. ACS NANO 2020; 14:7269-7279. [PMID: 32413259 DOI: 10.1021/acsnano.0c02491] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Understanding the nucleation and growth kinetics of thin films is a prerequisite for their large-scale utilization in devices. For self-assembled molecular phases near thermodynamic equilibrium the nucleation-growth kinetic models are still not developed. Here, we employ real-time low-energy electron microscopy (LEEM) to visualize a phase transformation induced by the carboxylation of 4,4'-biphenyl dicarboxylic acid on Ag(001) under ultra-high-vacuum conditions. The initial (α) and transformed (β) molecular phases are characterized in detail by X-ray photoemission spectroscopy, single-domain low-energy electron diffraction, room-temperature scanning tunneling microscopy, noncontact atomic force microscopy, and density functional theory calculations. The phase transformation is shown to exhibit a rich variety of phenomena, including Ostwald ripening of the α domains, burst nucleation of the β domains outside the α phase, remote dissolution of the α domains by nearby β domains, and a structural change from disorder to order. We show that all phenomena are well described by a general growth-conversion-growth (GCG) model. Here, the two-dimensional gas of admolecules has a dual role: it mediates mass transport between the molecular islands and hosts a slow deprotonation reaction. Further, we conclude that burst nucleation is consistent with a combination of rather weak intermolecular bonding and the onset of an additional weak many-body attractive interaction when a molecule is surrounded by its nearest neighbors. In addition, we conclude that Ostwald ripening and remote dissolution are essentially the same phenomenon, where a more stable structure grows at the expense of a kinetically formed, less stable entity via transport through the 2D gas. The proposed GCG model is validated through kinetic Monte Carlo (kMC) simulations.
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Affiliation(s)
- Pavel Procházka
- CEITEC, Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic
| | - Miguel A Gosalvez
- Department of Materials Physics, Faculty of Chemistry, University of the Basque Country UPV/EHU, Manuel Lardizabal 3, 20018 Donostia-San Sebastián, Spain
- Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Manuel Lardizabal 5, 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), Manuel Lardizabal 4, 20018 Donostia-San Sebastián, Spain
| | - Lukáš Kormoš
- CEITEC, Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Bruno de la Torre
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Aurelio Gallardo
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Prague, Czech Republic
| | - Joseba Alberdi-Rodriguez
- Department of Materials Physics, Faculty of Chemistry, University of the Basque Country UPV/EHU, Manuel Lardizabal 3, 20018 Donostia-San Sebastián, Spain
- Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Manuel Lardizabal 5, 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), Manuel Lardizabal 4, 20018 Donostia-San Sebastián, Spain
| | - Taras Chutora
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Anton O Makoveev
- CEITEC, Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Azin Shahsavar
- CEITEC, Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
| | - Andres Arnau
- Department of Materials Physics, Faculty of Chemistry, University of the Basque Country UPV/EHU, Manuel Lardizabal 3, 20018 Donostia-San Sebastián, Spain
- Centro de Física de Materiales CFM-Materials Physics Center MPC, Centro Mixto CSIC-UPV/EHU, Manuel Lardizabal 5, 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), Manuel Lardizabal 4, 20018 Donostia-San Sebastián, Spain
| | - Pavel Jelínek
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague 6, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Jan Čechal
- CEITEC, Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic
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