1
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Feitosa BDA, Torres BBM, Luginieski M, Coutinho DJ, Faria GC. Non-ideal nernstian behavior in organic electrochemical transistors: fundamental processes and theory. MATERIALS HORIZONS 2024. [PMID: 39320945 DOI: 10.1039/d4mh00758a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2024]
Abstract
Despite the successful implementation of organic electrochemical based devices (OEDs), fundamental processes that regulate their operations and sensing capabilities, specifically those related to ion-to-electron transduction, remain unclear. Indeed, there is still a lack of fundamental models to explain the steady-state and transient characteristics of OEDs, associating fundamentals of the physical-chemistry of the pair polymer-electrolyte with the output performance of such devices. In this study, we bring new highlights to a thermodynamic-based model that qualitatively and quantitatively describes OEDs operation, with a special focus on the organic electrochemical transistor (OECT). In this context, we introduce novel interpretations for traditional drain current models, grounded in thermodynamic and electrochemical principles. The model fitting parameters are correlated to the physical and chemical properties of the polymer-electrolyte pair, and it has been shown to explain trends observed in experimental results from the literature. Moreover, our model reveals that a non-Nerstian electrochemical behavior dominates OECT operation. Also, by analyzing experimental data, we are able to generate guidelines for material design and device development, targeting highly sensitive electrochemical biosensors and devices.
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Affiliation(s)
- Bianca de Andrade Feitosa
- Instituto de Física de São Carlos (USP), São Carlos-SP, 13566-590, Brazil.
- Escola de Engenharia de São Carlos (USP), São Carlos-SP, 13563-120, Brazil
| | | | - Marcos Luginieski
- Instituto de Física de São Carlos (USP), São Carlos-SP, 13566-590, Brazil.
| | - Douglas José Coutinho
- Universidade Tecnológica Federal do Paraná (UTFPR), Toledo-PR, 85902-490 Toledo-PR, Brazil
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2
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Zojer E. Electrostatically Designing Materials and Interfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2406178. [PMID: 39194368 DOI: 10.1002/adma.202406178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/08/2024] [Indexed: 08/29/2024]
Abstract
Collective electrostatic effects arise from the superposition of electrostatic potentials of periodically arranged (di)polar entities and are known to crucially impact the electronic structures of hybrid interfaces. Here, it is discussed, how they can be used outside the beaten paths of materials design for realizing systems with advanced and sometimes unprecedented properties. The versatility of the approach is demonstrated by applying electrostatic design not only to metal-organic interfaces and adsorbed (complex) monolayers, but also to inter-layer interfaces in van der Waals heterostructures, to polar metal-organic frameworks (MOFs), and to the cylindrical pores of covalent organic frameworks (COFs). The presented design ideas are straightforward to simulate and especially for metal-organic interfaces also their experimental implementation has been amply demonstrated. For van der Waals heterostructures, the needed building blocks are available, while the required assembly approaches are just being developed. Conversely, for MOFs the necessary growth techniques exist, but more work on advanced linker molecules is required. Finally, COF structures exist that contain pores decorated with polar groups, but the electrostatic impact of these groups has been largely ignored so far. All this suggest that the dawn of the age of electrostatic design is currently experienced with potential breakthroughs lying ahead.
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Affiliation(s)
- Egbert Zojer
- Institute of Solid State Physics, NAWI Graz, Petersgasse 16, Graz, A-8010, Austria
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3
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Shibuta M, Nakajima A. Imaging of ultrafast photoexcited electron dynamics in pentacene nanocrystals on a graphite substrate. NANOSCALE 2024; 16:12397-12405. [PMID: 38832543 DOI: 10.1039/d4nr00720d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Understanding molecular film growth on substrates and the ultrafast electron dynamics at their interface is crucial for advancing next-generation organic electronics. We have focused on studying the ultrafast photoexcited electron dynamics in nanoscale organic crystals of an aromatic molecule, pentacene, on a two-dimensional material of graphite substrate. Through the use of time-resolved two-photon photoelectron emission microscopy (2P-PEEM), we have visualized the ultrafast lateral evolution of photoexcited electrons. By resonantly tuning the incident photon to excite pentacene molecules, polarization-dependent 2P-PEEM has revealed that pentacene nanocrystals (sub- to several μm) on the substrate exhibit a preferential orientation, in which a molecular π-orbital contacts the substrate in a "lying flat" orientation, facilitating electron transfer to the substrate. The time-resolved 2P-PEEM captures the motion of excited electrons in a femto- to pico-second timescale, clearly imaging the ultrafast charge transfer and lateral expansion two-dimensionally on the graphite substrate. Moreover, we found that the lying-flat molecular orientation of pentacene nanocrystals is transformable into a "standing-up" one through gentle heating up to 50 °C. These experimental insights using time-resolved 2P-PEEM will be highly valuable in enhancing the photofunctionalities of organic electronic devices by controlled molecular deposition.
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Affiliation(s)
- Masahiro Shibuta
- Keio Institute of Pure and Applied Sciences (KiPAS), Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
| | - Atsushi Nakajima
- Keio Institute of Pure and Applied Sciences (KiPAS), Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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4
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Nowik-Boltyk EM, Junghoefer T, Giangrisostomi E, Ovsyannikov R, Shu C, Rajca A, Droghetti A, Casu MB. Radical-Induced Changes in Transition Metal Interfacial Magnetic Properties: A Blatter Derivative on Polycrystalline Cobalt. Angew Chem Int Ed Engl 2024:e202403495. [PMID: 38843268 DOI: 10.1002/anie.202403495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Indexed: 07/23/2024]
Abstract
In this work, we study the interface obtained by depositing a monolayer of a Blatter radical derivative on polycrystalline cobalt. By examining the occupied and unoccupied states at the interface, using soft X-ray techniques, combined with electronic structure calculations, we could simultaneously determine the electronic structure of both the molecular and ferromagnetic sides of the interface, thus obtaining a full understanding of the interfacial magnetic properties. We found that the molecule is strongly hybridized with the surface. Changes in the core level spectra reflect the modification of the molecule and the cobalt electronic structures inducing a decrease in the magnetic moment of the cobalt atoms bonded to the molecules which, in turn, lose their radical character. Our method allowed us to screen, beforehand, organic/ferromagnetic interfaces given their potential applications in spintronics.
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Affiliation(s)
| | - Tobias Junghoefer
- Institute of Physical and Theoretical Chemistry, University of Tübingen, 72076, Tübingen, Germany
| | - Erika Giangrisostomi
- Institute Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin, 12489, Berlin, Germany
| | - Ruslan Ovsyannikov
- Institute Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin, 12489, Berlin, Germany
| | - Chan Shu
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588, United States
| | - Andrea Droghetti
- School of Physics and CRANN, Trinity College, the University of Dublin, Dublin, D02, Ireland
| | - M Benedetta Casu
- Institute of Physical and Theoretical Chemistry, University of Tübingen, 72076, Tübingen, Germany
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5
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Swetha SV, Gayathri R, Ardra M, Imran PM, Nagarajan S. Inherent D-A Architecture in Indoloquinoxalines with an Array of Substituents for Non-Volatile Memory Device Applications. Chemphyschem 2024; 25:e202400003. [PMID: 38372587 DOI: 10.1002/cphc.202400003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 01/30/2024] [Accepted: 02/19/2024] [Indexed: 02/20/2024]
Abstract
Donor-acceptor (D-A)-based architecture has been the key to increase storage capability efficiency through the enhanced charge transportation in the fabricated device. We have designed and synthesized a series of functionalized indoloquinoxalines (IQ) for non-volatile organic memory devices. The investigation on UV-visible spectra reveals the absorption maxima of the compounds around 420 nm, attributed to the intramolecular charge transfer between indole and quinoxaline moiety. The irreversible anodic peak in the 1.0 to 1.5 V range indicates the indole moiety's oxidation ability. Besides, the cathodic peak in the range of -0.5 to -1.0 V, contributed to the stability of the reduced quinoxaline unit. All the compounds exhibited uniformly covered thin film in SEM analysis, potentially facilitating the seamless charge carrier migration between adjacent molecules. The methoxyphenyl substituted compound exhibited the binary write-once read-many (WORM) memory behavior with the lowest threshold voltage of -0.81 V. The molecular simulations displayed the efficient intramolecular charge transfer, providing the fabricated device's distinctive conductive states. Except for the tert-butylphenyl compound, which showed volatile dynamic random-access memory (DRAM) behavior, all the other compounds exhibited non-volatile WORM memory behavior, suggesting IQs potential as an intrinsic D-A molecule in organic memory devices on further structural refinement.
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Affiliation(s)
- Senthilkumar V Swetha
- Department of Chemistry, Central University of TamilNadu, Thiruvarur, 610 005, India
| | - Ramesh Gayathri
- Department of Chemistry, Central University of TamilNadu, Thiruvarur, 610 005, India
| | - Murali Ardra
- Department of Chemistry, Central University of TamilNadu, Thiruvarur, 610 005, India
| | | | - Samuthira Nagarajan
- Department of Chemistry, Central University of TamilNadu, Thiruvarur, 610 005, India
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6
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Pitfield J, Taylor NT, Hepplestone SP. Predicting Phase Stability at Interfaces. PHYSICAL REVIEW LETTERS 2024; 132:066201. [PMID: 38394598 DOI: 10.1103/physrevlett.132.066201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/21/2023] [Accepted: 12/22/2023] [Indexed: 02/25/2024]
Abstract
We present the RAFFLE methodology for structural prediction of the interface between two materials and demonstrate its effectiveness by applying it to MgO encapsulated by two layers of graphene. To address the challenge of interface structure prediction, our methodology combines physical insights derived from morphological features observed in related systems with an iterative machine learning technique. This employs physical-based methods, including void-filling and n-body distribution functions to predict interface structures. For the carbon-MgO encapsulated system, we have shown the rocksalt and hexagonal phases of MgO to be the two most energetically stable in the few-layer regime. We demonstrate that monolayer rocksalt is heavily stabilized by interfacing with graphene, becoming more energetically favorable than the graphenelike monolayer hexagonal MgO. The RAFFLE methodology provides valuable insights into interface behavior, and a route to finding new materials at interfaces.
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Affiliation(s)
- J Pitfield
- University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
| | - N T Taylor
- University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
| | - S P Hepplestone
- University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom
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7
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Ren S, Zhang W, Chen J, Yassar A. Theoretical and Experimental Study of Different Side Chains on 3,4-Ethylenedioxythiophene and Diketopyrrolopyrrole-Derived Polymers: Towards Organic Transistors. Int J Mol Sci 2024; 25:1099. [PMID: 38256172 PMCID: PMC10816275 DOI: 10.3390/ijms25021099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/09/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024] Open
Abstract
In this research, two polymers of P1 and P2 based on monomers consisting of thiophene, 3,4-Ethylenedioxythiophene (EDOT) and diketopyrrolopyrrole (DPP) are designed and obtained via Stille coupling polycondensation. The material shows excellent coplanarity and structural regularity due to the fine planarity of DPP itself and the weak non-covalent bonding interactions existing between the three units. Two different lengths of non-conjugated side chains are introduced and this has an effect on the intermolecular chain stacking, causing the film absorption to display different characteristic properties. On the other hand, the difference in the side chains does not have a significant effect on the thermal stability and the energy levels of the frontier orbitals of the materials, which is related to the fact that the materials both feature extremely high conjugation lengths and specific molecular compositions. Microscopic investigations targeting the side chains provide a contribution to the further design of organic semiconductor materials that meet device requirements. Tests based on organic transistors show a slight difference in conductivity between the two polymers, with P2 having better hole mobility than P1. This study highlights the importance of the impact of side chains on device performance, especially in the field of organic electronics.
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Affiliation(s)
- Shiwei Ren
- Advanced Materials Laboratory, Zhuhai-Fudan Innovation Institute, Guangdong-Macao in-Depth Cooperation Zone in Hengqin, Hengqin 519000, China;
| | - Wenqing Zhang
- Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China;
| | - Jinyang Chen
- Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China;
| | - Abderrahim Yassar
- Laboratory of Physics of Interfaces and Thin Films, Institut Polytechnique de Paris, 91128 Palaiseau, France
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8
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Kumar A, Betti MG, Mariani C, Kumar M, Gargiani P, Soncini C, Pedio M. Intermixing of Unoccupied States of Metal Phthalocyanine Chains Assembled on Au(110). NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:158. [PMID: 38251124 PMCID: PMC10819670 DOI: 10.3390/nano14020158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/29/2023] [Accepted: 01/05/2024] [Indexed: 01/23/2024]
Abstract
A detailed inverse photoemission study unveils the unoccupied electronic structure induced by the adsorption of CuPc and CoPc phthalocyanines on Au(110) reconstructed channels. The different behavior in the two systems is related to the different intermixing of orbitals with the underlying gold states. Broadening of the density of states at the Fermi level is detected after CoPc adsorption, absent in the case CuPc. A detailed comparison with the element-selective X-ray absorption spectroscopy enlightens and complements the IPES results and confirms a surface-driven intermixing of the CoPc orbitals involved in the interaction, with the out-of-plane Co 3dz2 orbital strongly hybridized with the gold electronic states. Moreover, the contribution of the 3d empty states to the IPES data is reported for FePc, CoPc, and CuPc thin films.
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Affiliation(s)
- Abhishek Kumar
- Istituto Officina dei Materiali-Consiglio Nazionale delle Ricerche, Basovizza SS-14, Km 163.5, 34012 Trieste, Italy; (A.K.); (M.K.); (C.S.)
- Department of Physics, University of Trieste, 34127 Trieste, Italy
| | - Maria Grazia Betti
- Dipartimento di Fisica, Università di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185 Roma, Italy; (M.G.B.); (C.M.)
| | - Carlo Mariani
- Dipartimento di Fisica, Università di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185 Roma, Italy; (M.G.B.); (C.M.)
| | - Manvendra Kumar
- Istituto Officina dei Materiali-Consiglio Nazionale delle Ricerche, Basovizza SS-14, Km 163.5, 34012 Trieste, Italy; (A.K.); (M.K.); (C.S.)
- Department of Physics, Institute of Science, Shri Vaishnav Vidyapeeth Vishwavidyalaya, Ujjain Road, Indore 453111, India
| | - Pierluigi Gargiani
- ALBA Synchrotron Light Source, Carrer de la Llum 2-26, 08290 Barcelona, Spain;
| | - Cristian Soncini
- Istituto Officina dei Materiali-Consiglio Nazionale delle Ricerche, Basovizza SS-14, Km 163.5, 34012 Trieste, Italy; (A.K.); (M.K.); (C.S.)
- Department of Physics, University of Trieste, 34127 Trieste, Italy
| | - Maddalena Pedio
- Istituto Officina dei Materiali-Consiglio Nazionale delle Ricerch, V. A. Pascoli s.n.c., 06123 Perugia, Italy
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9
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Niederreiter M, Cartus J, Werkovits A, Hofmann OT, Risse T, Sterrer M. Interplay of Adsorption Geometry and Work Function Evolution at the TCNE/Cu(111) Interface. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:24266-24273. [PMID: 38148848 PMCID: PMC10749461 DOI: 10.1021/acs.jpcc.3c06422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/28/2023]
Abstract
The adsorption of organic electron acceptors on metal surfaces is a powerful way to change the effective work function of the substrate through the formation of charge-transfer-induced dipoles. The work function of the interfaces is hence controlled by the redistribution of charges upon adsorption of the organic layer, which depends not only on the electron affinity of the organic material but also on the adsorption geometry. As shown in this work, the latter dependence controls the work function also in the case of adsorbate layers exhibiting a mixture of various adsorption geometries. Based on a combined experimental (core-level and infrared spectroscopy) and theoretical (density functional theory) study for tetracyanoethylene (TCNE) on Cu(111), we find that TCNE adsorbs in at least three different orientations, depending on TCNE coverage. At low coverage, flat lying TCNE dominates, as it possesses the highest adsorption energy. At a higher coverage, additionally, two different standing orientations are found. This is accompanied by a large increase in the work function of almost 3 eV at full monolayer coverage. Our results suggest that the large increase in work function is mainly due to the surface dipole of the free CN groups of the standing molecules and less dependent on the charge-transfer dipole of the differently oriented and charged molecules. This, in turn, opens new opportunities to control the work function of interfaces, e.g., by synthetic modification of the adsorbates, which may allow one to alter the adsorption geometries of the molecules as well as their contributions to the interface dipoles and, hence, the work function.
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Affiliation(s)
- Max Niederreiter
- Institute
of Physics, University of Graz, NAWI Graz, Universitätsplatz
5, 8010 Graz, Austria
| | - Johannes Cartus
- Institute
of Solid State Physics, Graz University
of Technology, NAWI Graz, Petersgasse, 16/II, 8010 Graz, Austria
| | - Anna Werkovits
- Institute
of Solid State Physics, Graz University
of Technology, NAWI Graz, Petersgasse, 16/II, 8010 Graz, Austria
| | - Oliver T. Hofmann
- Institute
of Solid State Physics, Graz University
of Technology, NAWI Graz, Petersgasse, 16/II, 8010 Graz, Austria
| | - Thomas Risse
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arminallee 22, 14195 Berlin, Germany
| | - Martin Sterrer
- Institute
of Physics, University of Graz, NAWI Graz, Universitätsplatz
5, 8010 Graz, Austria
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10
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Mansour A, Warren R, Lungwitz D, Forster M, Scherf U, Opitz A, Malischewski M, Koch N. Coordination of Tetracyanoquinodimethane-Derivatives with Tris(pentafluorophenyl)borane Provides Stronger p-Dopants with Enhanced Stability. ACS APPLIED MATERIALS & INTERFACES 2023; 15:46148-46156. [PMID: 37730205 PMCID: PMC10561139 DOI: 10.1021/acsami.3c10373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 08/18/2023] [Indexed: 09/22/2023]
Abstract
Strong molecular dopants for organic semiconductors that are stable against diffusion are in demand, enhancing the performance of organic optoelectronic devices. The conventionally used p-dopants based on 7,7,8,8-tetracyanoquinodimethane (TCNQ) and its derivatives "FxTCN(N)Q", such as 2,3,4,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (F6TCNNQ), feature limited oxidation strength, especially for modern polymer semiconductors with high ionization energy (IE). These small molecular dopants also exhibit pronounced diffusion in the polymer hosts. Here, we demonstrate a facile approach to increase the oxidation strength of FxTCN(N)Q by coordination with four tris(pentafluorophenyl)borane (BCF) molecules using a single-step solution mixing process, resulting in bulky dopant complexes "FxTCN(N)Q-4(BCF)". Using a series of polymer semiconductors with IE up to 5.9 eV, we show by optical absorption spectroscopy of solutions and thin films that the efficiency of doping using FxTCN(N)Q-4(BCF) is significantly higher compared to that using FxTCN(N)Q or BCF alone. Electrical transport measurements with the prototypical poly(3-hexylthiophene-2,5-diyl) (P3HT) confirm the higher doping efficiency of F4TCNQ-4(BCF) compared to F4TCNQ. Additionally, the bulkier structure of F4TCNQ-4(BCF) is shown to result in higher stability against drift in P3HT under an applied electric field as compared to F4TCNQ. The simple approach of solution-mixing of readily accessible molecules thus offers access to enhanced molecular p-dopants for the community.
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Affiliation(s)
- Ahmed
E. Mansour
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Ross Warren
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Dominique Lungwitz
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Michael Forster
- Department
of Chemistry and Wuppertal Center for Smart Materials and Systems
(CM@S), Bergische Universität Wuppertal, 42097 Wuppertal, Germany
| | - Ullrich Scherf
- Department
of Chemistry and Wuppertal Center for Smart Materials and Systems
(CM@S), Bergische Universität Wuppertal, 42097 Wuppertal, Germany
| | - Andreas Opitz
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Moritz Malischewski
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, 14195 Berlin, Germany
| | - Norbert Koch
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
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11
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Ferrari E, Pandolfi L, Schweicher G, Geerts Y, Salzillo T, Masino M, Venuti E. Interlayer Sliding Phonon Drives Phase Transition in the Ph-BTBT-10 Organic Semiconductor. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:5777-5783. [PMID: 37576586 PMCID: PMC10413852 DOI: 10.1021/acs.chemmater.3c00209] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 07/11/2023] [Indexed: 08/15/2023]
Abstract
In the field of organic electronics, the semiconductor 7-decyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) has become a benchmark due to its high charge mobility and chemical stability in thin film devices. Its phase diagram is characterized by a crystal phase with a bilayer structure that at high temperature transforms into a Smectic E liquid crystal with monolayer structure. As the charge transport properties appear to depend on the phase present in the thin film, the transition has been the subject of structural and computational studies. Here such a process has been investigated by polarized low frequency Raman spectroscopy, selectively probing the intermolecular dynamics of the two phases. The spectroscopic observations demonstrate the key role played by a displacive component of the transition, with the interpenetration of the crystal bilayers driven by lattice phonon mode softening followed by the intralayer rearrangement of the molecule rigid cores into the herringbone motif of the liquid crystal. The mechanism can be related to the effectiveness of thermal annealing to restore the crystal phase in films.
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Affiliation(s)
- Elena Ferrari
- Dipartimento
di Scienze Chimiche, della Vita e della
Sostenibilità Ambientale & INSTM-UdR Parma, Parco Area delle Scienze, 17/A, Parma 43124, Italy
- IMEM-CNR, Parco Area delle Scienze, 37/A, Parma 43124, Italy
| | - Lorenzo Pandolfi
- Dipartimento
di Chimica Industriale “Toso Montanari” & INSTM-UdR
Bologna, Viale del Risorgimento 4, Bologna 40136, Italy
| | - Guillaume Schweicher
- Laboratoire
de Chimie des Polymères Faculté des Sciences, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, CP 206/01, Brussels 1050, Belgium
| | - Yves Geerts
- Laboratoire
de Chimie des Polymères Faculté des Sciences, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, CP 206/01, Brussels 1050, Belgium
- International
Solvay Institutes of Physics and Chemistry Université Libre
de Bruxelles (ULB), Boulevard
du Triomphe, CP 206/01, Brussels 1050, Belgium
| | - Tommaso Salzillo
- Dipartimento
di Chimica Industriale “Toso Montanari” & INSTM-UdR
Bologna, Viale del Risorgimento 4, Bologna 40136, Italy
| | - Matteo Masino
- Dipartimento
di Scienze Chimiche, della Vita e della
Sostenibilità Ambientale & INSTM-UdR Parma, Parco Area delle Scienze, 17/A, Parma 43124, Italy
| | - Elisabetta Venuti
- Dipartimento
di Chimica Industriale “Toso Montanari” & INSTM-UdR
Bologna, Viale del Risorgimento 4, Bologna 40136, Italy
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12
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Ruiz VG, Wagner C, Maaß F, Arefi HH, Stremlau S, Tegeder P, Tautz FS, Tkatchenko A. Accurate quantification of the stability of the perylene-tetracarboxylic dianhydride on Au(111) molecule-surface interface. Commun Chem 2023; 6:136. [PMID: 37400714 DOI: 10.1038/s42004-023-00925-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 06/05/2023] [Indexed: 07/05/2023] Open
Abstract
Studying inorganic/organic hybrid systems is a stepping stone towards the design of increasingly complex interfaces. A predictive understanding requires robust experimental and theoretical tools to foster trust in the obtained results. The adsorption energy is particularly challenging in this respect, since experimental methods are scarce and the results have large uncertainties even for the most widely studied systems. Here we combine temperature-programmed desorption (TPD), single-molecule atomic force microscopy (AFM), and nonlocal density-functional theory (DFT) calculations, to accurately characterize the stability of a widely studied interface consisting of perylene-tetracarboxylic dianhydride (PTCDA) molecules on Au(111). This network of methods lets us firmly establish the adsorption energy of PTCDA/Au(111) via TPD (1.74 ± 0.10 eV) and single-molecule AFM (2.00 ± 0.25 eV) experiments which agree within error bars, exemplifying how implicit replicability in a research design can benefit the investigation of complex materials properties.
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Affiliation(s)
- Victor G Ruiz
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109, Berlin, Germany.
| | - Christian Wagner
- Peter Grünberg Institut, Forschungszentrum Jülich, 52425, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425, Jülich, Germany
| | - Friedrich Maaß
- Ruprecht-Karls-Universität Heidelberg, Physikalisch-Chemisches Institut, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Hadi H Arefi
- Peter Grünberg Institut, Forschungszentrum Jülich, 52425, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425, Jülich, Germany
| | - Stephan Stremlau
- Ruprecht-Karls-Universität Heidelberg, Physikalisch-Chemisches Institut, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Petra Tegeder
- Ruprecht-Karls-Universität Heidelberg, Physikalisch-Chemisches Institut, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - F Stefan Tautz
- Peter Grünberg Institut, Forschungszentrum Jülich, 52425, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425, Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074, Aachen, Germany
| | - Alexandre Tkatchenko
- Department of Physics and Materials Science, University of Luxembourg, L-1511, Luxembourg City, Luxembourg.
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13
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Joo E, Hur JW, Ko JY, Kim TG, Hwang JY, Smith KE, Lee H, Cho SW. Effects of HAT-CN Layer Thickness on Molecular Orientation and Energy-Level Alignment with ZnPc. Molecules 2023; 28:molecules28093821. [PMID: 37175231 PMCID: PMC10179936 DOI: 10.3390/molecules28093821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
Efficient energy-level alignment is crucial for achieving high performance in organic electronic devices. Because the electronic structure of an organic semiconductor is significantly influenced by its molecular orientation, comprehensively understanding the molecular orientation and electronic structure of the organic layer is essential. In this study, we investigated the interface between a 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) hole injection layer and a zinc-phthalocyanine (ZnPc) p-type organic semiconductor. To determine the energy-level alignment and molecular orientation, we conducted in situ ultraviolet and X-ray photoelectron spectroscopies, as well as angle-resolved X-ray absorption spectroscopy. We found that the HAT-CN molecules were oriented relatively face-on (40°) in the thin (5 nm) layer, whereas they were oriented relatively edge-on (62°) in the thick (100 nm) layer. By contrast, ZnPc orientation was not significantly altered by the underlying HAT-CN orientation. The highest occupied molecular orbital (HOMO) level of ZnPc was closer to the Fermi level on the 100 nm thick HAT-CN layer than on the 5 nm thick HAT-CN layer because of the higher work function. Consequently, a considerably low energy gap between the lowest unoccupied molecular orbital level of HAT-CN and the HOMO level of ZnPc was formed in the 100 nm thick HAT-CN case. This may improve the hole injection ability of the anode system, which can be utilized in various electronic devices.
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Affiliation(s)
- Eunah Joo
- Department of Physics and Engineering Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si 26493, Republic of Korea
| | - Jin Woo Hur
- Department of Physics and Engineering Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si 26493, Republic of Korea
| | - Joon Young Ko
- Department of Physics and Engineering Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si 26493, Republic of Korea
| | - Tae Gyun Kim
- Department of Physics and Engineering Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si 26493, Republic of Korea
| | - Jung Yeon Hwang
- Department of Physics and Engineering Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si 26493, Republic of Korea
| | - Kevin E Smith
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Hyunbok Lee
- Department of Physics and Institute of Quantum Convergence Technology, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon-si 24341, Republic of Korea
| | - Sang Wan Cho
- Department of Physics and Engineering Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si 26493, Republic of Korea
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14
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Cartus JJ, Jeindl A, Werkovits A, Hörmann L, Hofmann OT. Polymorphism mediated by electric fields: a first principles study on organic/inorganic interfaces. NANOSCALE ADVANCES 2023; 5:2288-2298. [PMID: 37056613 PMCID: PMC10089127 DOI: 10.1039/d2na00851c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 03/19/2023] [Indexed: 06/19/2023]
Abstract
Organic/inorganic interfaces are known to exhibit rich polymorphism, where different polymorphs often possess significantly different properties. Which polymorph forms during an experiment depends strongly on environmental parameters such as deposition temperature and partial pressure of the molecule to be adsorbed. To prepare desired polymorphs these parameters are varied. However, many polymorphs are difficult to access within the experimentally available temperature-pressure ranges. In this contribution, we investigate how electric fields can be used as an additional lever to make certain structures more readily accessible. On the example of tetracyanoethylene (TCNE) on Cu(111), we analyze how electric fields change the energy landscape of interface systems. TCNE on Cu(111) can form either lying or standing polymorphs, which exhibit significantly different work functions. We combine first-principles calculations with a machine-learning based structure search algorithm and ab initio thermodynamics to demonstrate that electric fields can be exploited to shift the temperature of the phase transition between standing and lying polymorphs by up to 100 K.
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Affiliation(s)
- Johannes J Cartus
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz Petersgasse 16 8010 Graz Austria
| | - Andreas Jeindl
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz Petersgasse 16 8010 Graz Austria
| | - Anna Werkovits
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz Petersgasse 16 8010 Graz Austria
| | - Lukas Hörmann
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz Petersgasse 16 8010 Graz Austria
| | - Oliver T Hofmann
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz Petersgasse 16 8010 Graz Austria
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15
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Tanguturi RG, Tsai JC, Li YS, Tsay JS. Structural characterization and electronic properties of Ni/rubrene bilayers with alternative stacking sequences. Phys Chem Chem Phys 2023; 25:7927-7936. [PMID: 36861757 DOI: 10.1039/d3cp00297g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Recent progress in organic electronics has attracted interest due to their excellent characteristics that include photovoltaic, light emission, and semiconducting behaviours. Spin-induced properties play important roles in organic electronics, while introducing spin into an organic layer in which spin responses, such as a weak spin-orbital coupling and long spin-relaxation time, allows a variety of spintronic applications to be achieved. However, such spin responses are rapidly attenuated by misalignment in the electronic structure of hybrid structures. We report herein on the energy level diagrams of Ni/rubrene bilayers that can be tuned by an alternating stacking. The band edges of the highest occupied molecular orbital (HOMO) levels were determined to be 1.24 and 0.48 eV relative to the Fermi level for Ni/rubrene/Si and rubrene/Ni/Si bilayers, respectively. This raises a possibility of accumulating electric dipoles at the ferromagnetic/organic semiconductor (FM/OSC) interface, which would inhibit the transfer of spin in the OSC layer. This phenomenon is caused by the formation of a Schottky-like barrier in the rubrene/Ni heterostructures. According to the information about the band edges of the HOMO levels, schematic plots of the HOMO shift in the electronic structure of the bilayers are presented. Based on the lower value of the effective uniaxial anisotropy for Ni/rubrene/Si, the uniaxial anisotropy was suppressed compared to that of rubrene/Ni/Si. The characteristics of the formation of Schottky barriers at the FM/OSC interface have an impact on the temperature-dependent spin states in the bilayers.
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Affiliation(s)
| | - Jian-Chen Tsai
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan.
| | - You-Siang Li
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan.
| | - Jyh-Shen Tsay
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan.
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16
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Lee H, Kim YE, Bae J, Jung S, Sporea RA, Kim CH. High-Performance Organic Source-Gated Transistors Enabled by the Indium-Tin Oxide-Diketopyrrolopyrrole Polymer Interface. ACS APPLIED MATERIALS & INTERFACES 2023; 15:10918-10925. [PMID: 36799771 DOI: 10.1021/acsami.2c22350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Source-gated transistors are a new driver of low-power high-gain thin-film electronics. However, source-gated transistors based on organic semiconductors are not widely investigated yet despite their potential for future display and sensor technologies. We report on the fabrication and modeling of high-performance organic source-gated transistors utilizing a critical junction formed between indium-tin oxide and diketopyrrolopyrrole polymer. This partially blocked hole-injection interface is shown to offer both a sufficient level of drain currents and a strong depletion effect necessary for source pinch-off. As a result, our transistors exhibit a set of outstanding metrics, including an intrinsic gain of 160 V/V, an output resistance of 4.6 GΩ, and a saturation coefficient of 0.2 at an operating voltage of 5 V. Drift-diffusion simulation is employed to reproduce and rationalize the experimental data. The modeling reveals that the effective contact length is significantly reduced in an interdigitated electrode geometry, eventually contributing to the realization of low-voltage saturation.
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Affiliation(s)
- Hyuna Lee
- School of Electronic Engineering, Gachon University, Seongnam 13120, Republic of Korea
| | - Yeo Eun Kim
- School of Electronic Engineering, Gachon University, Seongnam 13120, Republic of Korea
| | - Jisuk Bae
- School of Electronic Engineering, Gachon University, Seongnam 13120, Republic of Korea
| | - Sungyeop Jung
- Advanced Institute of Convergence Technology, Seoul National University, Suwon 16229, Republic of Korea
| | - Radu A Sporea
- Advanced Technology Institute, School of Computer Science and Electronic Engineering, University of Surrey, Guildford GU2 7XH, Surrey, U.K
| | - Chang-Hyun Kim
- School of Electronic Engineering, Gachon University, Seongnam 13120, Republic of Korea
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17
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Ishtaiwi Z, Taher D, Korb M, Helal W, Al-Hunaiti A, Juwhari HK, Amarne H, Amer MW, YouSef YA, Klaib S, Abu-Orabi ST. Syntheses, crystal structures, DFT calculation and solid-state spectroscopic properties of new zincate(II) complexes with N-(4-substituted phenyl)-N'-(4-nitrophenyl)-oxamate. ARAB J CHEM 2022. [DOI: 10.1016/j.arabjc.2022.104349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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18
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Haskew MJ, Nikman S, O'Sullivan CE, Galeb HA, Halcovitch NR, Hardy JG, Murphy ST. Mg/Zn metal‐air primary batteries using silk fibroin‐ionic liquid polymer electrolytes. NANO SELECT 2022. [DOI: 10.1002/nano.202200200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Mathew J. Haskew
- School of Engineering Lancaster University Bailrigg Lancaster UK
- Department of Chemistry Lancaster University Faraday Building Bailrigg Lancaster UK
| | - Shahin Nikman
- Department of Chemistry Lancaster University Faraday Building Bailrigg Lancaster UK
| | - Carys E. O'Sullivan
- Department of Chemistry Lancaster University Faraday Building Bailrigg Lancaster UK
| | - Hanaa A. Galeb
- Department of Chemistry Lancaster University Faraday Building Bailrigg Lancaster UK
- Department of Chemistry Science and Arts College, Rabigh Campus King Abdulaziz University Jeddah Saudi Arabia
| | - Nathan R. Halcovitch
- Department of Chemistry Lancaster University Faraday Building Bailrigg Lancaster UK
| | - John G. Hardy
- Department of Chemistry Lancaster University Faraday Building Bailrigg Lancaster UK
- Materials Science Institute Lancaster University Faraday Building, John Creed Avenue Bailrigg Lancaster UK
| | - Samuel T. Murphy
- School of Engineering Lancaster University Bailrigg Lancaster UK
- Materials Science Institute Lancaster University Faraday Building, John Creed Avenue Bailrigg Lancaster UK
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19
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Yang M, Zhao TX, Ji SC, Tao XD, Chen XL, Meng L, Liang D, Lu CZ. Voltage-Dependent Emission Varying from Blue to Orange–Red from a Nondoped Organic Light-Emitting Diode with a Single Emitter. NANOMATERIALS 2022; 12:nano12142333. [PMID: 35889558 PMCID: PMC9320025 DOI: 10.3390/nano12142333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/29/2022]
Abstract
Organic light-emitting diodes (OLEDs) with tunable emission colors, especially white OLEDs, have rarely been observed with a single emitter in a single emissive layer. In this paper, we report a new compound featuring a D–A–D structure, 9,9′-(pyrimidine-2,5-diylbis(2,1-phenylene))bis(3,6-di-tert-butyl-9H-carbazole) (PDPC). A nondoped OLED using this compound as a single emitter exhibits unique voltage-dependent dual emission. The emission colors range from blue to orange–red with an increase in voltage, during which white electroluminescence with a Commission Internationale De L’Eclairage (CIE) coordinate of (0.35, 0.29) and a color render index (CRI) value of 93 was observed. A comparative study revealed that the dual emission simultaneously originates from the monomers and excimers of the emitter. This study provides insight into understanding the multimer-excited mechanism and developing novel color-tunable OLEDs.
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Affiliation(s)
- Mingxue Yang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Tian-Xiang Zhao
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Si-Chao Ji
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xiao-Dong Tao
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xu-Lin Chen
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Lingyi Meng
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Dong Liang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
| | - Can-Zhong Lu
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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20
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Sohail U, Ullah F, Mahmood T, Muhammad S, Ayub K. Adsorption of Industrial Gases (CH 4, CO 2, and CO) on Olympicene: A DFT and CCSD(T) Investigation. ACS OMEGA 2022; 7:18852-18860. [PMID: 35694488 PMCID: PMC9178626 DOI: 10.1021/acsomega.2c01796] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/05/2022] [Indexed: 05/20/2023]
Abstract
Olympicene C19H12, an organic semiconductor, is investigated as an adsorption material for toxic industrial gas molecules such as CH4, CO2, and CO. A deep insight of complexation of CH4, CO2, and CO with olympicene (analyte@OLY) was obtained by interaction energy, symmetry-adopted perturbation theory (SAPT2+), quantum theory of atoms in molecules (QTAIM), density of states (DOS), noncovalent interaction (NCI), and frontier molecular orbital and natural bond orbital analysis. Domain-based local pair natural orbital coupled cluster theory single-point energy calculations were performed using the cc-pVTZ basis set in combination with corresponding auxiliary cc-pVTZ/JK and cc-pVTZ/C basis sets. For all property calculations of doped olympicene complexes, the ωB97M-V functional was employed. The stability trend for interaction energies is CO2@OLY > CH4@OLY > CO@OLY. QTAIM and NCI analysis confirmed the presence of NCIs, where the dispersion factor (in CH4@OLY) has the highest contribution, as revealed from SAPT2+. The chemical sensitivity of the system was evidenced by the origination of new energy states in DOS spectra. The recovery time for the analyte@OLY complex was calculated at 300 K, and an excellent recovery response was observed. All results evidently indicated weak interactions of the olympicene surface with CH4, CO2, and CO.
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Affiliation(s)
- Uroosa Sohail
- Department
of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan
| | - Faizan Ullah
- Department
of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan
| | - Tariq Mahmood
- Department
of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan
- Department
of Chemistry, College of Science, University
of Bahrain, P.O. Box
32038, Barhrain 1051, Bahrain
| | - Shabbir Muhammad
- Department
of Chemistry, College of Science, King Khalid
University, P.O. Box 9004, Abha 61413, Saudi Arabia
| | - Khurshid Ayub
- Department
of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan
- . Phone: +92-992-383591. Fax: +92-992-383441
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21
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Berger R, Jeindl A, Hörmann L, Hofmann OT. Role of Adatoms for the Adsorption of F4TCNQ on Au(111). THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:7718-7727. [PMID: 35558824 PMCID: PMC9082607 DOI: 10.1021/acs.jpcc.2c00994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/25/2022] [Indexed: 06/15/2023]
Abstract
Organic adlayers on inorganic substrates often contain adatoms, which can be incorporated within the adsorbed molecular species, forming two-dimensional metal-organic frameworks at the substrate surface. The interplay between native adatoms and adsorbed molecules significantly changes various adlayer properties such as the adsorption geometry, the bond strength between the substrate and the adsorbed species, or the work function at the interface. Here, we use dispersion-corrected density functional theory to gain insight into the energetics that drive the incorporation of native adatoms within molecular adlayers based on the prototypical, experimentally well-characterized system of F4TCNQ on Au(111). We explain the adatom-induced modifications in the adsorption geometry and the adsorption energy based on the electronic structure and charge transfer at the interface.
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Affiliation(s)
- Richard
K. Berger
- Institute of Solid State Physics, Graz University of Technology, 8010 Graz, Austria
| | - Andreas Jeindl
- Institute of Solid State Physics, Graz University of Technology, 8010 Graz, Austria
| | - Lukas Hörmann
- Institute of Solid State Physics, Graz University of Technology, 8010 Graz, Austria
| | - Oliver T. Hofmann
- Institute of Solid State Physics, Graz University of Technology, 8010 Graz, Austria
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22
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Zotti LA, Dednam W, Lombardi EB, Palacios JJ. Constrained DFT for Molecular Junctions. NANOMATERIALS 2022; 12:nano12071234. [PMID: 35407352 PMCID: PMC9002544 DOI: 10.3390/nano12071234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 02/01/2023]
Abstract
We have explored the use of constrained density functional theory (cDFT) for molecular junctions based on benzenediamine. By elongating the junction, we observe that the energy gap between the ionization potential and the electronic affinity increases with the stretching distance. This is consistent with the trend expected from the electrostatic screening. A more detailed analysis shows how this influences the charge distribution of both the individual metal layers and the molecular atoms. Overall, our work shows that constrained DFT is a powerful tool for studying screening effects in molecular junctions.
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Affiliation(s)
- Linda Angela Zotti
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain;
- Correspondence:
| | - Wynand Dednam
- Department of Physics, Science Campus, University of South Africa, Private Bag X6, Florida Park 1710, South Africa; (W.D.); (E.B.L.)
| | - Enrico B. Lombardi
- Department of Physics, Science Campus, University of South Africa, Private Bag X6, Florida Park 1710, South Africa; (W.D.); (E.B.L.)
| | - Juan Jose Palacios
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain;
- Departamento de Física de la Materia Condensada and Instituto Nicolás Cabrera (INC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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23
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Mansour AE, Valencia AM, Lungwitz D, Wegner B, Tanaka N, Shoji Y, Fukushima T, Opitz A, Cocchi C, Koch N. Understanding the evolution of the Raman spectra of molecularly p-doped poly(3-hexylthiophene-2,5-diyl): signatures of polarons and bipolarons. Phys Chem Chem Phys 2022; 24:3109-3118. [PMID: 35040854 DOI: 10.1039/d1cp04985b] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular doping is a key process to increase the density of charge carriers in organic semiconductors. Doping-induced charges in polymer semiconductors result in the formation of polarons and/or bipolarons due to the strong electron-vibron coupling in conjugated organic materials. Identifying the nature of charge carriers in doped polymers is essential to optimize the doping process for applications. In this work, we use Raman spectroscopy to investigate the formation of charge carriers in molecularly doped poly(3-hexylthiophene-2,5-diyl) (P3HT) for increasing dopant concentration, with the organic salt dimesityl borinium tetrakis(penta-fluorophenyl)borate (Mes2B+ [B(C6F5)4]-) and the Lewis acid tris(pentafluorophenyl)borane [B(C6F5)3]. While the Raman signatures of neutral P3HT and singly charged P3HT segments (polarons) are known, the Raman spectra of doubly charged P3HT segments (bipolarons) are not yet sufficiently understood. Combining Raman spectroscopy measurements on doped P3HT thin films with first-principles calculations on oligomer models, we explain the evolution of the Raman spectra from neutral P3HT to increasingly doped P3HT featuring polarons and eventually bipolarons at high doping levels. We identify and explain the origin of the spectral features related to bipolarons by tracing the Raman signature of the symmetric collective vibrations along the polymer backbone, which - compared to neutral P3HT - redshifts for polarons and blueshifts for bipolarons. This is explained by a planarization of the singly charged P3HT segments with polarons and rather high order in thin films, while the doubly charged segments with bipolarons are located in comparably disordered regions of the P3HT film due to the high dopant concentration. Furthermore, we identify additional Raman peaks associated with vibrations in the quinoid doubly charged segments of the polymer. Our results offer the opportunity for readily identifying the nature of charge carriers in molecularly doped P3HT while taking advantage of the simplicity, versatility, and non-destructive nature of Raman spectroscopy.
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Affiliation(s)
- Ahmed E Mansour
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - Ana M Valencia
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Carl von Ossietzky Universität Oldenburg, Institute of Physics, 26129 Oldenburg, Germany
| | - Dominique Lungwitz
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
| | - Berthold Wegner
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - Naoki Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Yoshiaki Shoji
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Takanori Fukushima
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Andreas Opitz
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
| | - Caterina Cocchi
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Carl von Ossietzky Universität Oldenburg, Institute of Physics, 26129 Oldenburg, Germany
| | - Norbert Koch
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
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24
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Werkovits A, Jeindl A, Hörmann L, Cartus JJ, Hofmann OT. Toward Targeted Kinetic Trapping of Organic–Inorganic Interfaces: A Computational Case Study. ACS PHYSICAL CHEMISTRY AU 2022; 2:38-46. [PMID: 35098244 PMCID: PMC8796281 DOI: 10.1021/acsphyschemau.1c00015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 11/29/2022]
Abstract
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Properties of inorganic–organic interfaces, such as their
interface dipole, strongly depend on the structural arrangements of
the organic molecules. A prime example is tetracyanoethylene (TCNE)
on Cu(111), which shows two different phases with significantly different
work functions. However, the thermodynamically preferred phase is
not always the one that is best suited for a given application. Rather,
it may be desirable to selectively grow a kinetically trapped structure.
In this work, we employ density functional theory and transition state
theory to discuss under which conditions such a kinetic trapping might
be possible for the model system of TCNE on Cu. Specifically, we want
to trap the molecules in the first layer in a flat-lying orientation.
This requires temperatures that are sufficiently low to suppress the
reorientation of the molecules, which is thermodynamically more favorable
for high dosages, but still high enough to enable ordered growth through
diffusion of molecules. On the basis of the temperature-dependent
diffusion and reorientation rates, we propose a temperature range
at which the reorientation can be successfully suppressed.
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Affiliation(s)
- Anna Werkovits
- Institute of Solid State Physics, TU Graz, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria
| | - Andreas Jeindl
- Institute of Solid State Physics, TU Graz, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria
| | - Lukas Hörmann
- Institute of Solid State Physics, TU Graz, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria
| | - Johannes J. Cartus
- Institute of Solid State Physics, TU Graz, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria
| | - Oliver T. Hofmann
- Institute of Solid State Physics, TU Graz, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria
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25
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Borchert JW, Weitz RT, Ludwigs S, Klauk H. A Critical Outlook for the Pursuit of Lower Contact Resistance in Organic Transistors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2104075. [PMID: 34623710 DOI: 10.1002/adma.202104075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/20/2021] [Indexed: 06/13/2023]
Abstract
To take full advantage of recent and anticipated improvements in the performance of organic semiconductors employed in organic transistors, the high contact resistance arising at the interfaces between the organic semiconductor and the source and drain contacts must be reduced significantly. To date, only a small portion of the accumulated research on organic thin-film transistors (TFTs) has reported channel-width-normalized contact resistances below 100 Ωcm, well above what is regularly demonstrated in transistors based on inorganic semiconductors. A closer look at these cases and the relevant literature strongly suggests that the most significant factor leading to the lowest contact resistances in organic TFTs so far has been the control of the thin-film morphology of the organic semiconductor. By contrast, approaches aimed at increasing the charge-carrier density and/or reducing the intrinsic Schottky barrier height have so far played a relatively minor role in achieving the lowest contact resistances. Herein, the possible explanations for these observations are explored, including the prevalence of Fermi-level pinning and the difficulties in forming optimized interfaces with organic semiconductors. An overview of the research on these topics is provided, and potential device-engineering solutions are discussed based on recent advancements in the theoretical and experimental work on both organic and inorganic semiconductors.
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Affiliation(s)
- James W Borchert
- 1st Institute of Physics, Georg August University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - R Thomas Weitz
- 1st Institute of Physics, Georg August University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Sabine Ludwigs
- IPOC - Functional Polymers, Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Hagen Klauk
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569, Stuttgart, Germany
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26
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Cartus J, Jeindl A, Hofmann OT. Can We Predict Interface Dipoles Based on Molecular Properties? ACS OMEGA 2021; 6:32270-32276. [PMID: 34870047 PMCID: PMC8638305 DOI: 10.1021/acsomega.1c05092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/02/2021] [Indexed: 05/12/2023]
Abstract
We apply high-throughput density functional theory calculations and symbolic regression to hybrid inorganic/organic interfaces with the intent to extract physically meaningful correlations between the adsorption-induced work function modifications and the properties of the constituents. We separately investigate two cases: (1) hypothetical, free-standing self-assembled monolayers with a large intrinsic dipole moment and (2) metal-organic interfaces with a large charge-transfer-induced dipole. For the former, we find, without notable prior assumptions, the Topping model, as expected from the literature. For the latter, highly accurate correlations are found, which are, however, clearly unphysical.
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27
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Islam MF, Sindt AJ, Hossain MS, Ayare PJ, Smith MD, Vannucci AK, Garashchuk S, Shimizu LS. Assembled triphenylamine bis-urea macrocycles: exploring photodriven electron transfer from host to guests. Phys Chem Chem Phys 2021; 23:23953-23960. [PMID: 34661219 DOI: 10.1039/d1cp03000k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Absorption of electronic acceptors in the accessible channels of an assembled triphenylamine (TPA) bis-urea macrocycle 1 enabled the study of electron transfer from the walls of the TPA framework to the encapsulated guests. The TPA host is isoskeletal in all host-guest structures analyzed with guests 2,1,3-benzothiadiazole, 2,5-dichlorobenzoquinone and I2 loading in single-crystal-to-single-crystal transformations. Analysis of the crystal structures highlights how the spatial proximity and orientation of the TPA host and the entrapped guests influence their resulting photophysical properties and allow direct comparison of the different donor-acceptor complexes. Diffuse reflectance spectroscopy shows that upon complex formation 1·2,5-dichlorobenzoquinone exhibits a charge transfer (CT) transition. Whereas, the 1·2,1,3-benzothiadiazole complex undergoes a photoinduced electron transfer (PET) upon irradiation with 365 nm LEDs. The CT absorptions were also identified with the aid of time dependent density functional theory (TD-DFT) calculations. Cyclic voltammetry experiments show that 2,1,3-benzothiadiazole undergoes reversible reduction within the host-guest complex. Moreover, the optical band gaps of the host 1·2,5-dichlorobenzoquinone (1.66 eV), and host 1·2,1,3-benzothiadiazole (2.15 eV) complexes are significantly smaller as compared to the free host 1 material (3.19 eV). Overall, understanding this supramolecular electron transfer strategy should pave the way towards designing lower band gap inclusion complexes.
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Affiliation(s)
- Md Faizul Islam
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Ammon J Sindt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Muhammad Saddam Hossain
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Pooja J Ayare
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Mark D Smith
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Aaron K Vannucci
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Sophya Garashchuk
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
| | - Linda S Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia South Carolina 29208, USA.
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28
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Burmeister D, Trunk MG, Bojdys MJ. Development of metal-free layered semiconductors for 2D organic field-effect transistors. Chem Soc Rev 2021; 50:11559-11576. [PMID: 34661213 PMCID: PMC8521667 DOI: 10.1039/d1cs00497b] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Indexed: 12/23/2022]
Abstract
To this day, the active components of integrated circuits consist mostly of (semi-)metals. Concerns for raw material supply and pricing aside, the overreliance on (semi-)metals in electronics limits our abilities (i) to tune the properties and composition of the active components, (ii) to freely process their physical dimensions, and (iii) to expand their deployment to applications that require optical transparency, mechanical flexibility, and permeability. 2D organic semiconductors match these criteria more closely. In this review, we discuss a number of 2D organic materials that can facilitate charge transport across and in-between their π-conjugated layers as well as the challenges that arise from modulation and processing of organic polymer semiconductors in electronic devices such as organic field-effect transistors.
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Affiliation(s)
- David Burmeister
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
- Integrative Research Institute for the Sciences Adlershof, Humboldt-Universität zu Berlin, Zum Großen Windkanal 2, 12489 Berlin, Germany
| | - Matthias G Trunk
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
- Integrative Research Institute for the Sciences Adlershof, Humboldt-Universität zu Berlin, Zum Großen Windkanal 2, 12489 Berlin, Germany
| | - Michael J Bojdys
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
- Integrative Research Institute for the Sciences Adlershof, Humboldt-Universität zu Berlin, Zum Großen Windkanal 2, 12489 Berlin, Germany
- Department of Chemistry, King's College London, Britannia House Guy's Campus, 7 Trinity Street, London, SE1 1DB, UK
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29
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Stein A, Rolf D, Lotze C, Feldmann S, Gerbert D, Günther B, Jeindl A, Cartus JJ, Hofmann OT, Gade LH, Franke KJ, Tegeder P. Electronic Properties of Tetraazaperopyrene Derivatives on Au(111): Energy-Level Alignment and Interfacial Band Formation. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:19969-19979. [PMID: 34557263 PMCID: PMC8450938 DOI: 10.1021/acs.jpcc.1c04217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/18/2021] [Indexed: 06/13/2023]
Abstract
N-heteropolycyclic aromatic compounds are promising organic electron-transporting semiconductors for applications in field-effect transistors. Here, we investigated the electronic properties of 1,3,8,10-tetraazaperopyrene derivatives adsorbed on Au(111) using a complementary experimental approach, namely, scanning tunneling spectroscopy and two-photon photoemission combined with state-of-the-art density functional theory. We find signatures of weak physisorption of the molecular layers, such as the absence of charge transfer, a nearly unperturbed surface state, and an intact herringbone reconstruction underneath the molecular layer. Interestingly, molecular states in the energy region of the sp- and d-bands of the Au(111) substrate exhibit hole-like dispersive character. We ascribe this band character to hybridization with the delocalized states of the substrate. We suggest that such bands, which leave the molecular frontier orbitals largely unperturbed, are a promising lead for the design of organic-metal interfaces with a low charge injection barrier.
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Affiliation(s)
- Arnulf Stein
- Physikalisch-Chemisches
Institut, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany
| | - Daniela Rolf
- Fachbereich
Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Christian Lotze
- Fachbereich
Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Sascha Feldmann
- Physikalisch-Chemisches
Institut, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany
| | - David Gerbert
- Physikalisch-Chemisches
Institut, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany
| | - Benjamin Günther
- Anorganisch-Chemisches
Institut, Universität Heidelberg, Im Neuenheimer Feld 270, D-69120 Heidelberg, Germany
| | - Andreas Jeindl
- Technische
Universität Graz, Institut für Festkörperphysik, NAWI Graz, Petersgasse 16, 8010 Graz, Austria
| | - Johannes J. Cartus
- Technische
Universität Graz, Institut für Festkörperphysik, NAWI Graz, Petersgasse 16, 8010 Graz, Austria
| | - Oliver T. Hofmann
- Technische
Universität Graz, Institut für Festkörperphysik, NAWI Graz, Petersgasse 16, 8010 Graz, Austria
| | - Lutz H. Gade
- Anorganisch-Chemisches
Institut, Universität Heidelberg, Im Neuenheimer Feld 270, D-69120 Heidelberg, Germany
| | - Katharina J. Franke
- Fachbereich
Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Petra Tegeder
- Physikalisch-Chemisches
Institut, Universität Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany
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30
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Belser A, Greulich K, Sättele MS, Fingerle M, Ovsyannikov R, Giangrisostomi E, Chassé T, Peisert H. Interface Properties of CoPc on Nanographene-Covered Au(111) and the Influence of Annealing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:10750-10761. [PMID: 34464137 DOI: 10.1021/acs.langmuir.1c01438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Organic bilayer systems and heterostructures are of enormous importance for optoelectronic devices. We study interface properties and the structural ordering of cobalt phthalocyanine (CoPc) on a highly ordered monolayer hexa-peri-hexabenzocoronene (HBC), grown on Au(111), using photoemission, X-ray absorption, scanning tunneling microscopy, and low-energy electron diffraction. A charge transfer between CoPc and the gold substrate is almost completely prevented by the HBC intermediate layer. We show that HBC acts as a template for the initial growth of CoPc molecules. After annealing to 630 K, a molecular exchange takes place, resulting in a coexistence of domains of both CoPc and HBC molecules on the surface.
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Affiliation(s)
- Axel Belser
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Katharina Greulich
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Marie S Sättele
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
- Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Michael Fingerle
- Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Ruslan Ovsyannikov
- Institute for Methods and Instrumentation in Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin 12489, Germany
| | - Erika Giangrisostomi
- Institute for Methods and Instrumentation in Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin 12489, Germany
| | - Thomas Chassé
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+) at the University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Heiko Peisert
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
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31
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Okutan M, Coşkun R, Öztürk M, Yalçın O, Toker C. Equivalent circuit properties of organic food extracts doped hydrogels and their applications in bioelectronics. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Sattari-Esfahlan SM, Lee EC, Kim CH. Synergistic Effects of Self-Assembled Monolayers in Solution-Processed 6,13-Bis(triisopropylsilylethynyl)Pentacene Transistors. Chemphyschem 2021; 22:1706-1711. [PMID: 34101321 DOI: 10.1002/cphc.202100261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/14/2021] [Indexed: 12/15/2022]
Abstract
Organic semiconductors are highly interface-sensitive, and therefore chemical functionalization using self-assembled monolayers (SAMs) is often adopted to tailor their properties. This study clarifies the synergistic effects of electrode and dielectric SAMs on the behavior of solution-processed organic field-effect transistors (OFETs). Utilization of a self-consistent device model enables a physically robust treatment of the measured electrical characteristics of the OFETs, thus providing highly reliable materials, interface, morphology, and transport parameters. These parameters are further extended and correlated to build a comprehensive picture on trap energy and injection-transport relationship, finally revealing a set of fundamental insights into chemically modified OFETs.
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Affiliation(s)
- S M Sattari-Esfahlan
- Department of Electronic Engineering, Gachon University, Seongnam, 13120, Republic of Korea
| | - Eun-Cheol Lee
- Department of Physics, Gachon University, Seognam, 13120, Republic of Korea
| | - Chang-Hyun Kim
- Department of Electronic Engineering, Gachon University, Seongnam, 13120, Republic of Korea
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33
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Park S, Mutz N, Kovalenko SA, Schultz T, Shin D, Aljarb A, Li L, Tung V, Amsalem P, List‐Kratochvil EJW, Stähler J, Xu X, Blumstengel S, Koch N. Type-I Energy Level Alignment at the PTCDA-Monolayer MoS 2 Interface Promotes Resonance Energy Transfer and Luminescence Enhancement. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2100215. [PMID: 34194946 PMCID: PMC8224443 DOI: 10.1002/advs.202100215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/24/2021] [Indexed: 06/13/2023]
Abstract
Van der Waals heterostructures consisting of 2D semiconductors and conjugated molecules are of increasing interest because of the prospect of a synergistic enhancement of (opto)electronic properties. In particular, perylenetetracarboxylic dianhydride (PTCDA) on monolayer (ML)-MoS2 has been identified as promising candidate and a staggered type-II energy level alignment and excited state interfacial charge transfer have been proposed. In contrast, it is here found with inverse and direct angle resolved photoelectron spectroscopy that PTCDA/ML-MoS2 supported by insulating sapphire exhibits a straddling type-I level alignment, with PTCDA having the wider energy gap. Photoluminescence (PL) and sub-picosecond transient absorption measurements reveal that resonance energy transfer, i.e., electron-hole pair (exciton) transfer, from PTCDA to ML-MoS2 occurs on a sub-picosecond time scale. This gives rise to an enhanced PL yield from ML-MoS2 in the heterostructure and an according overall modulation of the photoresponse. These results underpin the importance of a precise knowledge of the interfacial electronic structure in order to understand excited state dynamics and to devise reliable design strategies for optimized optoelectronic functionality in van der Waals heterostructures.
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Affiliation(s)
- Soohyung Park
- Advanced Analysis CenterKorea Institute of Science and Technology (KIST)Seoul02792South Korea
| | - Niklas Mutz
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
| | | | - Thorsten Schultz
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Helmholtz‐Zentrum für Materialien und Energie GmbHBerlin12489Germany
| | - Dongguen Shin
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
| | - Areej Aljarb
- Physical Sciences and EngineeringKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Lain‐Jong Li
- Department of Mechanical EngineeringThe University of Hong KongPokfulam RoadHong Kong
| | - Vincent Tung
- Physical Sciences and EngineeringKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Patrick Amsalem
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
| | - Emil J. W. List‐Kratochvil
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Humboldt‐Universität zu BerlinInstitut für ChemieBerlin12489Germany
- Helmholtz‐Zentrum für Materialien und Energie GmbHBerlin12489Germany
| | - Julia Stähler
- Humboldt‐Universität zu BerlinInstitut für ChemieBerlin12489Germany
| | - Xiaomin Xu
- Shenzhen Geim Graphene CenterTsinghua‐Berkeley Shenzhen InstituteTsinghua UniversityShenzhen518055China
| | - Sylke Blumstengel
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Humboldt‐Universität zu BerlinInstitut für ChemieBerlin12489Germany
| | - Norbert Koch
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Helmholtz‐Zentrum für Materialien und Energie GmbHBerlin12489Germany
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34
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Karstens R, Chassé T, Peisert H. Interface interaction of transition metal phthalocyanines with strontium titanate (100). BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:485-496. [PMID: 34104625 PMCID: PMC8144905 DOI: 10.3762/bjnano.12.39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
We study interface properties of CoPcF x and FePcFx (x = 0 or 16) on niobium-doped SrTiO3(100) surfaces using mainly X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. For all studied molecules, a rather complex, bidirectional charge transfer with the oxide substrate was observed, involving both the macrocycle and the central metal atom. For molecules of the first monolayer, an electron transfer to the central metal atom is concluded from transition metal 2p core level photoemission spectra. The number of interacting molecules in the first monolayer on the oxide surface depends on the central metal atom of the phthalocyanine, whereas the substrate preparation has minor influence on the interaction between CoPc and SrTiO3(100). Differences of the interaction mechanism to related TiO2 surfaces are discussed.
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Affiliation(s)
- Reimer Karstens
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Thomas Chassé
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
- Center for Light–Matter Interaction, Sensors & Analytics (LISA+) at the University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Heiko Peisert
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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35
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Improving organic photovoltaic cells by forcing electrode work function well beyond onset of Ohmic transition. Nat Commun 2021; 12:2250. [PMID: 33854070 PMCID: PMC8047006 DOI: 10.1038/s41467-021-22358-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 02/23/2021] [Indexed: 12/03/2022] Open
Abstract
As electrode work function rises or falls sufficiently, the organic semiconductor/electrode contact reaches Fermi-level pinning, and then, few tenths of an electron-volt later, Ohmic transition. For organic solar cells, the resultant flattening of open-circuit voltage (Voc) and fill factor (FF) leads to a ‘plateau’ that maximizes power conversion efficiency (PCE). Here, we demonstrate this plateau in fact tilts slightly upwards. Thus, further driving of the electrode work function can continue to improve Voc and FF, albeit slowly. The first effect arises from the coercion of Fermi level up the semiconductor density-of-states in the case of ‘soft’ Fermi pinning, raising cell built-in potential. The second effect arises from the contact-induced enhancement of majority-carrier mobility. We exemplify these using PBDTTPD:PCBM solar cells, where PBDTTPD is a prototypal face-stacked semiconductor, and where work function of the hole collection layer is systematically ‘tuned’ from onset of Fermi-level pinning, through Ohmic transition, and well into the Ohmic regime. Both open-circuit voltage and fill factor of organic solar cells are affected by the metal-organic semiconductor interface. Here, the authors demonstrate that the voltage can continue to rise when the Fermi level is forced up to the semiconductor density-of-states tail.
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36
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Hofmann OT, Zojer E, Hörmann L, Jeindl A, Maurer RJ. First-principles calculations of hybrid inorganic-organic interfaces: from state-of-the-art to best practice. Phys Chem Chem Phys 2021; 23:8132-8180. [PMID: 33875987 PMCID: PMC8237233 DOI: 10.1039/d0cp06605b] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/05/2021] [Indexed: 12/18/2022]
Abstract
The computational characterization of inorganic-organic hybrid interfaces is arguably one of the technically most challenging applications of density functional theory. Due to the fundamentally different electronic properties of the inorganic and the organic components of a hybrid interface, the proper choice of the electronic structure method, of the algorithms to solve these methods, and of the parameters that enter these algorithms is highly non-trivial. In fact, computational choices that work well for one of the components often perform poorly for the other. As a consequence, default settings for one materials class are typically inadequate for the hybrid system, which makes calculations employing such settings inefficient and sometimes even prone to erroneous results. To address this issue, we discuss how to choose appropriate atomistic representations for the system under investigation, we highlight the role of the exchange-correlation functional and the van der Waals correction employed in the calculation and we provide tips and tricks how to efficiently converge the self-consistent field cycle and to obtain accurate geometries. We particularly focus on potentially unexpected pitfalls and the errors they incur. As a summary, we provide a list of best practice rules for interface simulations that should especially serve as a useful starting point for less experienced users and newcomers to the field.
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Affiliation(s)
- Oliver T Hofmann
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria.
| | - Egbert Zojer
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria.
| | - Lukas Hörmann
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria.
| | - Andreas Jeindl
- Institute of Solid State Physics, Graz University of Technology, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria.
| | - Reinhard J Maurer
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
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Salomón FF, Vega NC, Jurado JP, Morán Vieyra FE, Tirado M, Comedi D, Campoy-Quiles M, Cattaneo M, Katz NE. Heteroleptic Ruthenium(II) Complexes with 2,2'-Bipyridines Having Carbonitriles as Anchoring Groups for ZnO Surfaces: Syntheses, Physicochemical Properties, and Applications in Organic Solar Cells. Inorg Chem 2021; 60:5660-5672. [PMID: 33821633 DOI: 10.1021/acs.inorgchem.0c03691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heteroleptic ruthenium (II) complexes were used for sensitizing ZnO surfaces in organic solar cells (OSCs) as mediators with photoactive layers. The complexes [Ru(4,4'-X2-bpy)(Mebpy-CN)2]2+ (with X = -CH3, -OCH3 and -N(CH3)2; bpy = 2,2'-bipyridine; Mebpy-CN = 4-methyl-2,2'-bipyridine-4'-carbonitrile) were synthesized and studied by analytical and spectroscopical techniques. Spectroscopic, photophysical, and electrochemical properties were tuned by changing the electron-donating ability of the -X substituents at the 4,4'-positions of the bpy ring and rationalized by quantum mechanical calculations. These complexes were attached through nitrile groups to ZnO as interfacial layer in an OSC device with a PBDB-T:ITIC photoactive layer. This modified inorganic electron transport layer generates enhancement in photoconversion of the solar cells, reaching up to a 23% increase with respect to the unsensitized OSCs. The introduction of these dyes suppresses some degradative reactions of the nonfullerene acceptor due to the photocatalytic activity of zinc oxide, which was maintained stable for about 11 months. Improving OSC efficiencies and stabilities can thus be achieved by a judicious combination of new inorganic and organic materials.
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Affiliation(s)
- Fernando F Salomón
- INQUINOA (CONICET-UNT), Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Argentina
| | - Nadia C Vega
- INFINOA (CONICET-UNT), NANOPROJECT, Depto. de Física, FACET, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina
| | - José Piers Jurado
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, España
| | - Faustino E Morán Vieyra
- INBIONATEC (CONICET-UNSE), Laboratorio de Cinética y Fotoquímica, Universidad Nacional de Santiago del Estero, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - Mónica Tirado
- INFINOA (CONICET-UNT), NANOPROJECT, Depto. de Física, FACET, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina
| | - David Comedi
- INFINOA (CONICET-UNT), NANOPROJECT, Depto. de Física, FACET, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina
| | - Mariano Campoy-Quiles
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, España
| | - Mauricio Cattaneo
- INQUINOA (CONICET-UNT), Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Argentina
| | - Néstor E Katz
- INQUINOA (CONICET-UNT), Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000 San Miguel de Tucumán, Argentina
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38
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Park S, Choi S, Lee H, Lee J, Woo Y, Jung YJ, Jung YM, Jeong J, Park J, Yi Y, Park S, Lee H. Impact of gamma-ray irradiation on the electronic structures of PCBM and P3HT organic semiconductor films. Polym Degrad Stab 2021. [DOI: 10.1016/j.polymdegradstab.2021.109518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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39
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Weymouth AJ, Riegel E, Simmet B, Gretz O, Giessibl FJ. Lateral Force Microscopy Reveals the Energy Barrier of a Molecular Switch. ACS NANO 2021; 15:3264-3271. [PMID: 33523628 DOI: 10.1021/acsnano.0c09965] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Copper phthalocyanine (CuPc) is a small molecule often used in organic light emitting diodes where it is deposited on a conducting electrode. Previous scanning tunneling microscopy (STM) studies of CuPc on Cu(111) have shown that inelastic tunneling events can cause CuPc to switch between a ground state and two symmetrically equivalent metastable states in which the molecule is rotated. We investigated CuPc on Cu(111) and Ag(111) with STM and lateral force microscopy (LFM). Even without inelastic events, the presence of the tip can induce rotations and upon closer approach, causes the rotated states to be favored. Combining STM measurements at various temperatures and LFM measurements, we show that the long-range attraction of the tip changes the potential energy landscape of this molecular switch. We can also determine the geometry of the rotated and ground states. We compare our observations of CuPc on Cu(111) to CuPc on Ag(111). On Ag(111), CuPc appears flat and does not rotate. Stronger bonding typically involves shorter bond lengths, larger shifts of energy levels, and structural stability. Although the binding of CuPc to Cu(111) is stronger than that on Ag(111), the nonplanar geometry of CuPc on Cu(111) is accompanied by two metastable states which are not present on the Ag(111) surface.
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Affiliation(s)
| | | | | | - Oliver Gretz
- University of Regensburg, Regensburg 93053, Germany
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40
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Braun K, Hauler O, Zhang D, Wang X, Chassé T, Meixner AJ. Probing Bias-Induced Electron Density Shifts in Metal-Molecule Interfaces via Tip-Enhanced Raman Scattering. J Am Chem Soc 2021; 143:1816-1821. [PMID: 33492134 DOI: 10.1021/jacs.0c09392] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Surface charging effects at metal-molecule interfaces, for example, charge transfer, charge transport, charge injection, and so on, have a strong impact on the performance of organic electronics. Only having molecules bound or adsorbed on different metals results in a doping-like behavior at the interface by the different work functions of the metals and creates hybrid surface states, which strongly affect the efficiencies. With the ongoing downsizing and thinning of the organic components, the impact of the interface will even further increase. However, most of the investigations only monitor the interface without the additional charging effects from applying a voltage to the interface. In this work we present a spectroscopic approach based on tip-enhanced Raman spectroscopy (TERS) to study metal-molecule interfaces with an applied voltage simulating the electric field strength in real devices. We monitor how an intrinsic inductive effect of partial functional groups in molecules can shift the molecular electron density (ED) distribution when a bias voltage is applied. Therefore, we choose two molecules as model systems, which are similar in size and binding condition to a smooth gold surface, but with different electronic structure. By placing the tip 1 nm over the molecular surface at a fixed position and changing the applied bias voltage, we record electric-field-dependent tip-enhanced Raman spectra. Specific vibrational bands exhibit voltage-dependent intensity changes related to the shift of the local ED inside the molecules. We believe this experiment is valuable to gain deeper insights into charged metal-molecule interfaces.
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Affiliation(s)
- Kai Braun
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.,Center for Light-Matter Interaction, Sensors & Analytics (LISA+), University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Otto Hauler
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Dai Zhang
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.,Center for Light-Matter Interaction, Sensors & Analytics (LISA+), University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Xiao Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, School of Physics and Electronics, Hunan University, Changsha, Hunan 410012, China
| | - Thomas Chassé
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.,Center for Light-Matter Interaction, Sensors & Analytics (LISA+), University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.,Center for Light-Matter Interaction, Sensors & Analytics (LISA+), University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
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41
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Fidanyan K, Hamada I, Rossi M. Quantum Nuclei at Weakly Bonded Interfaces: The Case of Cyclohexane on Rh(111). ADVANCED THEORY AND SIMULATIONS 2021. [DOI: 10.1002/adts.202000241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Karen Fidanyan
- Fritz Haber Institute of the Max Planck Society Faradayweg 4‐6 Berlin 14195 Germany
- Max Planck Institute for the Structure and Dynamics of Matter Luruper Chaussee 149 Hamburg 22761 Germany
| | - Ikutaro Hamada
- Department of Precision Engineering Graduate School of Engineering Osaka University 2‐1 Yamadaoka Suita Osaka 565‐0871 Japan
| | - Mariana Rossi
- Fritz Haber Institute of the Max Planck Society Faradayweg 4‐6 Berlin 14195 Germany
- Max Planck Institute for the Structure and Dynamics of Matter Luruper Chaussee 149 Hamburg 22761 Germany
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42
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Mirzehmet A, Ohtsuka T, Abd Rahman SA, Yuyama T, Krüger P, Yoshida H. Surface Termination of Solution-Processed CH 3NH 3PbI 3 Perovskite Film Examined using Electron Spectroscopies. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004981. [PMID: 33617084 DOI: 10.1002/adma.202004981] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/19/2020] [Indexed: 05/21/2023]
Abstract
The interfaces of a perovskite solar cell significantly influence the charge processes in the cell, which contributes to the device performance with direct implication for surface potential, electronic structure, and chemical reactivity. The properties of the interface are strongly affected by the surface termination. In this work, the combination of ultraviolet photoelectron spectroscopy (UPS) and metastable-atom electron spectroscopy is demonstrated, to examine the surface termination of a solution-processed CH3NH3PbI3 perovskite film. The results show that the surface of the CH3NH3PbI3 perovskite film is terminated with a layer consisting of CH3NH3 and I. The interface energy level alignment for both occupied and unoccupied levels between CH3NH3PbI3 and C60 is also examined using UPS and low-energy inverse photoelectron spectroscopy. It turns out that an ideal energy level alignment is established for the electron collection and hole block at the perovskite and C60 interface.
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Affiliation(s)
- Abduheber Mirzehmet
- Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Tomoki Ohtsuka
- Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Syed A Abd Rahman
- Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Tomoki Yuyama
- Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Peter Krüger
- Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
- Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Hiroyuki Yoshida
- Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
- Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
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43
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Zhao Y, Liu X, Li L, Wang S, Li Y, Xie H, Niu D, Huang H, Gao Y. Modification of an ultrathin C 60 interlayer on the electronic structure and molecular packing of C8-BTBT on HOPG. Phys Chem Chem Phys 2020; 22:25264-25271. [PMID: 33135703 DOI: 10.1039/d0cp04288a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), atomic force microscopy (AFM) and X-ray diffraction (XRD) were applied to investigate the electronic structure and molecular packing of C8-BTBT on HOPG with an ultrathin C60 interlayer. It was found that C8-BTBT displays a Vollmer-Weber (V-W) growth mode on HOPG, with an ultrathin C60 interlayer (0.7 nm). Compared to the uniform lying-down growth mode as directly grown on HOPG, the C8-BTBT molecules here adopt a lying-down orientation at low coverage with some small tilt angles because the π-π interaction between C8-BTBT and HOPG is partly disturbed by the C60 interlayer, delivering a higher highest occupied molecular orbital (HOMO) in C8-BTBT. An interface dipole of 0.14 eV is observed due to electron transport from C8-BTBT to C60. The upward and downward band bending in C8-BTBT and C60, respectively, near the C8-BTBT/C60 interface reduces the hole transport barrier at the interface, facilitating the hole injection from C60 to C8-BTBT, while a large electron transfer barrier from C60 to C8-BTBT is detected at this interface, which effectively limits electron injection from C60 to C8-BTBT. The HOMO of C8-BTBT near the interface is largely lifted up by the C60 insertion layer, which causes a p-doping effect and increases the hole mobility in C8-BTBT. Furthermore, owing to the lowest occupied molecular orbital (LUMO) of C60 residing in the gap of C8-BTBT, charge transfer occurs between C60 and the trap states in C8-BTBT to effectively passivate the trapping states. Our efforts aid a better understanding of the electron structure and film growth of anisotropic molecules and provide a useful strategy to improve the performance of C8-BTBT-based devices.
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Affiliation(s)
- Yuan Zhao
- School of Physics and Electronics, Central South University, Changsha, 410083, P. R. China
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44
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Lo MF, Ng TW, Shen D, Lee CS. Charge Energetics and Electronic Level Changes At the Copper(II) Phthalocyanine/Fullerene Junction Upon Photoexcitation. ACS APPLIED MATERIALS & INTERFACES 2020; 12:42992-42996. [PMID: 32845116 DOI: 10.1021/acsami.0c08497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Energy offset at the donor (D)/acceptor (A) interface plays an important role in charge separation in organic photovoltaics. Its magnitude determines the charge separation process under illumination. Extensive studies have been carried out for elucidating the charge transfer (CT) process at different D/A junctions. These works lead to two different views: upon photoexcitation, energies would be (1) consumed in molecular polarization and orientation such that those opposite charges would overcome mutual Coulombic attractive potential at the interface and (2) spent on promoting charges to high-lying delocalized energy states (i.e., hot states), which is necessarily important prior to charge separation. Under these two scheme of studies, the electronic structures and the charge behaviors at the D/A interface should be different under photoexcitation, yet there is so far no direct experimental approach for probing the changes in electronics structures (i.e., Fermi level, vacuum level, frontier molecular orbitals, etc.) upon photoexcitation. Herein, a modified photoelectron spectroscopy (PES) system with an additional solar simulator is used to study the charge distributions and electronic interactions for a standard D/A heterojunction (i.e., copper phthalocyanine (CuPc)/ fullerene (C60)) under photoexcitation. CT states formed as a result of photon energy transfer at the CuPc/C60 junction. Subsequent superpositions of charge transfer and electron polarization effects increase the D/A energy level offsets from 0.75 (ground state measured in the dark) to 1.07 eV (high-lying state measured upon illumination). We showed that there is excess energy consumed for a subtle change in the energy level alignment of the CuPc/C60 junction under illumination, suggesting a new insight for the energy loss mechanism during the photocharge generation processes.
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Affiliation(s)
- Ming-Fai Lo
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518000, P. R. China
| | - Tsz-Wai Ng
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518000, P. R. China
| | - Dong Shen
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR, P. R. China
| | - Chun-Sing Lee
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, Hong Kong SAR, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518000, P. R. China
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45
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Wang Q, Chen MT, Franco-Cañellas A, Shen B, Geiger T, F. Bettinger H, Schreiber F, Salzmann I, Gerlach A, Duhm S. Impact of fluorination on interface energetics and growth of pentacene on Ag(111). BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:1361-1370. [PMID: 32974114 PMCID: PMC7492695 DOI: 10.3762/bjnano.11.120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/19/2020] [Indexed: 05/26/2023]
Abstract
We studied the structural and electronic properties of 2,3,9,10-tetrafluoropentacene (F4PEN) on Ag(111) via X-ray standing waves (XSW), low-energy electron diffraction (LEED) as well as ultraviolet and X-ray photoelectron spectroscopy (UPS and XPS). XSW revealed that the adsorption distances of F4PEN in (sub)monolayers on Ag(111) were 3.00 Å for carbon atoms and 3.05 Å for fluorine atoms. The F4PEN monolayer was essentially lying on Ag(111), and multilayers adopted π-stacking. Our study shed light not only on the F4PEN-Ag(111) interface but also on the fundamental adsorption behavior of fluorinated pentacene derivatives on metals in the context of interface energetics and growth mode.
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Affiliation(s)
- Qi Wang
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Meng-Ting Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, People’s Republic of China
| | - Antoni Franco-Cañellas
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Bin Shen
- Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Thomas Geiger
- Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Holger F. Bettinger
- Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Ingo Salzmann
- Department of Physics, Department of Chemistry & Biochemistry, Concordia University, 7141 Sherbrooke St. West, Montreal, Quebec H4B 1R6, Canada
| | - Alexander Gerlach
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Steffen Duhm
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, People’s Republic of China
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46
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Franco-Cañellas A, Duhm S, Gerlach A, Schreiber F. Binding and electronic level alignment of π-conjugated systems on metals. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2020; 83:066501. [PMID: 32101802 DOI: 10.1088/1361-6633/ab7a42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We review the binding and energy level alignment of π-conjugated systems on metals, a field which during the last two decades has seen tremendous progress both in terms of experimental characterization as well as in the depth of theoretical understanding. Precise measurements of vertical adsorption distances and the electronic structure together with ab initio calculations have shown that most of the molecular systems have to be considered as intermediate cases between weak physisorption and strong chemisorption. In this regime, the subtle interplay of different effects such as covalent bonding, charge transfer, electrostatic and van der Waals interactions yields a complex situation with different adsorption mechanisms. In order to establish a better understanding of the binding and the electronic level alignment of π-conjugated molecules on metals, we provide an up-to-date overview of the literature, explain the fundamental concepts as well as the experimental techniques and discuss typical case studies. Thereby, we relate the geometric with the electronic structure in a consistent picture and cover the entire range from weak to strong coupling.
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Affiliation(s)
- Antoni Franco-Cañellas
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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47
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Michnowicz T, Borca B, Pétuya R, Schendel V, Pristl M, Pentegov I, Kraft U, Klauk H, Wahl P, Mutombo P, Jelínek P, Arnau A, Schlickum U, Kern K. Controlling Single Molecule Conductance by a Locally Induced Chemical Reaction on Individual Thiophene Units. Angew Chem Int Ed Engl 2020; 59:6207-6212. [PMID: 31965698 PMCID: PMC7187382 DOI: 10.1002/anie.201915200] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/04/2020] [Indexed: 11/09/2022]
Abstract
Among the prerequisites for the progress of single-molecule-based electronic devices are a better understanding of the electronic properties at the individual molecular level and the development of methods to tune the charge transport through molecular junctions. Scanning tunneling microscopy (STM) is an ideal tool not only for the characterization, but also for the manipulation of single atoms and molecules on surfaces. The conductance through a single molecule can be measured by contacting the molecule with atomic precision and forming a molecular bridge between the metallic STM tip electrode and the metallic surface electrode. The parameters affecting the conductance are mainly related to their electronic structure and to the coupling to the metallic electrodes. Here, the experimental and theoretical analyses are focused on single tetracenothiophene molecules and demonstrate that an in situ-induced direct desulfurization reaction of the thiophene moiety strongly improves the molecular anchoring by forming covalent bonds between molecular carbon and copper surface atoms. This bond formation leads to an increase of the conductance by about 50 % compared to the initial state.
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Affiliation(s)
- Tomasz Michnowicz
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
| | - Bogdana Borca
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
- National Institute of Materials PhysicsAtomistilor Strasse, No. 405A077125MagureleRomania
- Present address: Institute of Applied PhysicsTechnische Universität BraunschweigMendelssohnstrasse 238106BraunschweigGermany
| | - Rémi Pétuya
- Institution: Donostia International Physics CentrePaseo Manuel de Lardizabal 420018Donostia—San SebastiánSpain
- Present address: University of LiverpoolDepartment of ChemistryCrown StreetLiverpoolL69 7ZDUK
| | - Verena Schendel
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
| | - Marcel Pristl
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
| | - Ivan Pentegov
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
| | - Ulrike Kraft
- Department of Organic ElectronicsMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
- Present address: University of CambridgeCavendish LaboratoryJ J Thomson AvenueCambridgeCB3 0HEUK
| | - Hagen Klauk
- Department of Organic ElectronicsMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
| | - Peter Wahl
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
- SUPASchool of Physics and AstronomyUniversity of St AndrewsNorth HaughSt AndrewsKY16 9SSUK
| | - Pingo Mutombo
- Nanosurf LabInstitute of Physics of the Czech Academy of ScienceCukrovarnicka 1016253Praha 6Czech Republic
| | - Pavel Jelínek
- Nanosurf LabInstitute of Physics of the Czech Academy of ScienceCukrovarnicka 1016253Praha 6Czech Republic
| | - Andrés Arnau
- Institution: Donostia International Physics CentrePaseo Manuel de Lardizabal 420018Donostia—San SebastiánSpain
- UPV/EHU and Material Physics Center (MPC)Centro Mixto CSIC-UPV/EHUPaseo Manuel de Lardizabal 520018Donostia—San SebastiánSpain
| | - Uta Schlickum
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
- Institute of Applied PhysicsTechnische Universität BraunschweigMendelssohnstraße 238106BraunschweigGermany
| | - Klaus Kern
- Department of Nanoscale ScienceMax Planck Institute for Solid State ResearchHeisenbergstrasse 170569StuttgartGermany
- Institut de PhysiqueÉcole Polytechnique Fédérale de Lausanne (EPFL)EPFL SB IPHYS-Direction Bâtiment PH, Station 31015LausanneSwitzerland
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48
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Michnowicz T, Borca B, Pétuya R, Schendel V, Pristl M, Pentegov I, Kraft U, Klauk H, Wahl P, Mutombo P, Jelínek P, Arnau A, Schlickum U, Kern K. Controlling Single Molecule Conductance by a Locally Induced Chemical Reaction on Individual Thiophene Units. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201915200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tomasz Michnowicz
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
| | - Bogdana Borca
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
- National Institute of Materials Physics Atomistilor Strasse, No. 405A 077125 Magurele Romania
- Present address: Institute of Applied PhysicsTechnische Universität Braunschweig Mendelssohnstrasse 2 38106 Braunschweig Germany
| | - Rémi Pétuya
- Institution: Donostia International Physics Centre Paseo Manuel de Lardizabal 4 20018 Donostia—San Sebastián Spain
- Present address: University of LiverpoolDepartment of Chemistry Crown Street Liverpool L69 7ZD UK
| | - Verena Schendel
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
| | - Marcel Pristl
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
| | - Ivan Pentegov
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
| | - Ulrike Kraft
- Department of Organic ElectronicsMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
- Present address: University of CambridgeCavendish Laboratory J J Thomson Avenue Cambridge CB3 0HE UK
| | - Hagen Klauk
- Department of Organic ElectronicsMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
| | - Peter Wahl
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
- SUPASchool of Physics and AstronomyUniversity of St Andrews North Haugh St Andrews KY16 9SS UK
| | - Pingo Mutombo
- Nanosurf LabInstitute of Physics of the Czech Academy of Science Cukrovarnicka 10 16253 Praha 6 Czech Republic
| | - Pavel Jelínek
- Nanosurf LabInstitute of Physics of the Czech Academy of Science Cukrovarnicka 10 16253 Praha 6 Czech Republic
| | - Andrés Arnau
- Institution: Donostia International Physics Centre Paseo Manuel de Lardizabal 4 20018 Donostia—San Sebastián Spain
- UPV/EHU and Material Physics Center (MPC)Centro Mixto CSIC-UPV/EHU Paseo Manuel de Lardizabal 5 20018 Donostia—San Sebastián Spain
| | - Uta Schlickum
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
- Institute of Applied PhysicsTechnische Universität Braunschweig Mendelssohnstraße 2 38106 Braunschweig Germany
| | - Klaus Kern
- Department of Nanoscale ScienceMax Planck Institute for Solid State Research Heisenbergstrasse 1 70569 Stuttgart Germany
- Institut de PhysiqueÉcole Polytechnique Fédérale de Lausanne (EPFL) EPFL SB IPHYS-Direction Bâtiment PH, Station 3 1015 Lausanne Switzerland
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49
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Wang Q, Franco-Cañellas A, Yang J, Hausch J, Struzek S, Chen M, Thakur PK, Gerlach A, Duhm S, Schreiber F. Heteromolecular Bilayers on a Weakly Interacting Substrate: Physisorptive Bonding and Molecular Distortions of Copper-Hexadecafluorophthalocyanine. ACS APPLIED MATERIALS & INTERFACES 2020; 12:14542-14551. [PMID: 32109044 DOI: 10.1021/acsami.9b22812] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Heteromolecular bilayers of π-conjugated organic molecules on metals, considered as model systems for more complex thin film heterostructures, are investigated with respect to their structural and electronic properties. By exploring the influence of the organic-metal interaction strength in bilayer systems, we determine the molecular arrangement in the physisorptive regime for copper-hexadecafluorophthalocyanine (F16CuPc) on Au(111) with intermediate layers of 5,7,12,14-pentacenetetrone and perylene-3,4,9,10-tetracarboxylic diimide. Using the X-ray standing wave technique to distinguish the different molecular layers, we show that these two bilayers are ordered following their deposition sequence. Surprisingly, F16CuPc as the second layer within the heterostructures exhibits an inverted intramolecular distortion compared to its monolayer structure.
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Affiliation(s)
- Qi Wang
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | | | - Jiacheng Yang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, People's Republic of China
| | - Julian Hausch
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Samuel Struzek
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Mengting Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, People's Republic of China
| | - Pardeep Kumar Thakur
- Diamond Light Source, Harwell Science and Innovation Campus, Oxfordshire OX11 0DE, United Kingdom
| | - Alexander Gerlach
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Steffen Duhm
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, People's Republic of China
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
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50
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García-Iglesias M, Mayoral MJ, Serrano-Molina D, Aparicio F, Vázquez-González V, González-Rodríguez D. Self-Assembly of Diacetylene-Bridged Phenylenevinylene Oligomers in Water and Organic Solvents. Chempluschem 2020; 84:488-492. [PMID: 31943897 DOI: 10.1002/cplu.201900207] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/23/2019] [Indexed: 11/06/2022]
Abstract
Rodlike π-conjugated molecules in which two OPV fragments are connected through a diacetylene bond self-assemble in aqueous and organic media. Optical spectroscopy and AFM measurements indicated that, in water, strong hydrophobic interactions between π-cores promote aggregation into robust, uniform micellar structures. In contrast, in apolar solvents, a fibrilar morphology is obtained by coiling of columnar stacks. These stacks are formed in a nucleation-elongation process with degrees of cooperativity of 0.006, that is influenced by the low rotation barriers around the σ-bonds in the diacetylene linker.
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Affiliation(s)
- Miguel García-Iglesias
- Departamento de Química Orgánica Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - María José Mayoral
- Departamento de Química Orgánica Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - David Serrano-Molina
- Departamento de Química Orgánica Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Fátima Aparicio
- Departamento de Química Orgánica Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Violeta Vázquez-González
- Departamento de Química Orgánica Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - David González-Rodríguez
- Departamento de Química Orgánica Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049, Madrid, Spain
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