1
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Hawkey A, Dash A, Rodríguez-Martínez X, Zhao Z, Champ A, Lindenthal S, Zharnikov M, Kemerink M, Zaumseil J. Ion-Exchange Doping of Semiconducting Single-Walled Carbon Nanotubes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2404554. [PMID: 39104286 DOI: 10.1002/adma.202404554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 07/04/2024] [Indexed: 08/07/2024]
Abstract
Semiconducting single-walled carbon nanotubes (SWCNTs) are a promising thermoelectric material with high power factors after chemical p- or n-doping. Understanding the impact of dopant counterions on charge transport and thermoelectric properties of nanotube networks is essential to further optimize doping methods and to develop better dopants. This work utilizes ion-exchange doping to systematically vary the size of counterions in thin films of small and large diameter, polymer-sorted semiconducting SWCNTs with AuCl3 as the initial p-dopant and investigates the impact of ion size on conductivity, Seebeck coefficients, and power factors. Larger anions are found to correlate with higher electrical conductivities and improved doping stability, while no significant effect on the power factors is found. Importantly, the effect of counterion size on the thermoelectric properties of dense SWCNT networks is not obscured by morphological changes upon doping. The observed trends of carrier mobilities and Seebeck coefficients can be explained by a random resistor model for the nanotube network that accounts for overlapping Coulomb potentials leading to the formation of an impurity band whose depth depends on the carrier density and counterion size. These insights can be applied more broadly to understand the thermoelectric properties of doped percolating disordered systems, including semiconducting polymers.
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Affiliation(s)
- Angus Hawkey
- Institute for Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Aditya Dash
- Institute for Molecular Systems Engineering and Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | | | - Zhiyong Zhao
- Institute for Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Anna Champ
- Department of Chemistry, Columbia University, New York, New York, 10027, USA
| | - Sebastian Lindenthal
- Institute for Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Michael Zharnikov
- Institute for Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Martijn Kemerink
- Institute for Molecular Systems Engineering and Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
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2
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Jacobs IE, Lin Y, Huang Y, Ren X, Simatos D, Chen C, Tjhe D, Statz M, Lai L, Finn PA, Neal WG, D'Avino G, Lemaur V, Fratini S, Beljonne D, Strzalka J, Nielsen CB, Barlow S, Marder SR, McCulloch I, Sirringhaus H. High-Efficiency Ion-Exchange Doping of Conducting Polymers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2102988. [PMID: 34418878 DOI: 10.1002/adma.202102988] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Molecular doping-the use of redox-active small molecules as dopants for organic semiconductors-has seen a surge in research interest driven by emerging applications in sensing, bioelectronics, and thermoelectrics. However, molecular doping carries with it several intrinsic problems stemming directly from the redox-active character of these materials. A recent breakthrough was a doping technique based on ion-exchange, which separates the redox and charge compensation steps of the doping process. Here, the equilibrium and kinetics of ion exchange doping in a model system, poly(2,5-bis(3-alkylthiophen-2-yl)thieno(3,2-b)thiophene) (PBTTT) doped with FeCl3 and an ionic liquid, is studied, reaching conductivities in excess of 1000 S cm-1 and ion exchange efficiencies above 99%. Several factors that enable such high performance, including the choice of acetonitrile as the doping solvent, which largely eliminates electrolyte association effects and dramatically increases the doping strength of FeCl3 , are demonstrated. In this high ion exchange efficiency regime, a simple connection between electrochemical doping and ion exchange is illustrated, and it is shown that the performance and stability of highly doped PBTTT is ultimately limited by intrinsically poor stability at high redox potential.
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Affiliation(s)
- Ian E Jacobs
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Yue Lin
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Yuxuan Huang
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Xinglong Ren
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Dimitrios Simatos
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Chen Chen
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Dion Tjhe
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Martin Statz
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Lianglun Lai
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Peter A Finn
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - William G Neal
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Gabriele D'Avino
- Grenoble Alpes University, CNRS, Grenoble INP, Institut Néel, 25 rue des Martyrs, Grenoble, 38042, France
| | - Vincent Lemaur
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, B-7000, Belgium
| | - Simone Fratini
- Grenoble Alpes University, CNRS, Grenoble INP, Institut Néel, 25 rue des Martyrs, Grenoble, 38042, France
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, B-7000, Belgium
| | - Joseph Strzalka
- X-Ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Christian B Nielsen
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Stephen Barlow
- School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Seth R Marder
- School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Iain McCulloch
- KAUST Solar Center, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955, Saudi Arabia
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Henning Sirringhaus
- Optoelectronics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
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3
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Wu R, Matta M, Paulsen BD, Rivnay J. Operando Characterization of Organic Mixed Ionic/Electronic Conducting Materials. Chem Rev 2022; 122:4493-4551. [PMID: 35026108 DOI: 10.1021/acs.chemrev.1c00597] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Operando characterization plays an important role in revealing the structure-property relationships of organic mixed ionic/electronic conductors (OMIECs), enabling the direct observation of dynamic changes during device operation and thus guiding the development of new materials. This review focuses on the application of different operando characterization techniques in the study of OMIECs, highlighting the time-dependent and bias-dependent structure, composition, and morphology information extracted from these techniques. We first illustrate the needs, requirements, and challenges of operando characterization then provide an overview of relevant experimental techniques, including spectroscopy, scattering, microbalance, microprobe, and electron microscopy. We also compare different in silico methods and discuss the interplay of these computational methods with experimental techniques. Finally, we provide an outlook on the future development of operando for OMIEC-based devices and look toward multimodal operando techniques for more comprehensive and accurate description of OMIECs.
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Affiliation(s)
- Ruiheng Wu
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Micaela Matta
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Bryan D Paulsen
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Jonathan Rivnay
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, United States
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4
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Scaccabarozzi AD, Basu A, Aniés F, Liu J, Zapata-Arteaga O, Warren R, Firdaus Y, Nugraha MI, Lin Y, Campoy-Quiles M, Koch N, Müller C, Tsetseris L, Heeney M, Anthopoulos TD. Doping Approaches for Organic Semiconductors. Chem Rev 2021; 122:4420-4492. [PMID: 34793134 DOI: 10.1021/acs.chemrev.1c00581] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Electronic doping in organic materials has remained an elusive concept for several decades. It drew considerable attention in the early days in the quest for organic materials with high electrical conductivity, paving the way for the pioneering work on pristine organic semiconductors (OSCs) and their eventual use in a plethora of applications. Despite this early trend, however, recent strides in the field of organic electronics have been made hand in hand with the development and use of dopants to the point that are now ubiquitous. Here, we give an overview of all important advances in the area of doping of organic semiconductors and their applications. We first review the relevant literature with particular focus on the physical processes involved, discussing established mechanisms but also newly proposed theories. We then continue with a comprehensive summary of the most widely studied dopants to date, placing particular emphasis on the chemical strategies toward the synthesis of molecules with improved functionality. The processing routes toward doped organic films and the important doping-processing-nanostructure relationships, are also discussed. We conclude the review by highlighting how doping can enhance the operating characteristics of various organic devices.
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Affiliation(s)
- Alberto D Scaccabarozzi
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Aniruddha Basu
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Filip Aniés
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, U.K
| | - Jian Liu
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg 412 96, Sweden
| | - Osnat Zapata-Arteaga
- Materials Science Institute of Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Spain
| | - Ross Warren
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Yuliar Firdaus
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia.,Research Center for Electronics and Telecommunication, Indonesian Institute of Science, Jalan Sangkuriang Komplek LIPI Building 20 level 4, Bandung 40135, Indonesia
| | - Mohamad Insan Nugraha
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Yuanbao Lin
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Mariano Campoy-Quiles
- Materials Science Institute of Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Spain
| | - Norbert Koch
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekulé-Strasse 5, 12489 Berlin, Germany.,Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg 412 96, Sweden
| | - Leonidas Tsetseris
- Department of Physics, National Technical University of Athens, Athens GR-15780, Greece
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, U.K
| | - Thomas D Anthopoulos
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
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5
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Geng K, Xie Q, Zhao Y, Yang L, Song Y, Hou H. Unlocking the Remarkable Influence of Intramolecular Group Rotation for Third-order Nonlinear Optical Properties. Chem Asian J 2021; 16:981-987. [PMID: 33751826 DOI: 10.1002/asia.202100160] [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: 02/14/2021] [Revised: 03/06/2021] [Indexed: 12/23/2022]
Abstract
This work exposes for the first time the remarkable influence of intramolecular group rotation on third-order nonlinear optical (NLO) performance. In order to prove the role of group rotation, we designed and synthesized two photo-response compounds tetramethyl 5,5'-(((diazene-1,2-diylbis(4,1-phenylene))bis(oxy))bis(methylene))diisophthalate (1) and 5,5'-(((diazene-1,2-diylbis(4,1-phenylene))bis(oxy))bis(methylene))diisophthalic acid (2) and investigated their NLO performance under different substituent (benzyloxy group) rotation states. 1 and 2 have dynamic benzyloxy group rotation in dilute solution and shows reverse saturated absorption (RSA). When the benzyloxy group rotation of 1 and 2 was restricted by PMMA, their NLO performance not only converted into saturated absorption (SA) and NLO refraction behaviours, but also hardly changed after isomerization. Interestingly, we also restricted the benzyloxy group rotation in solution to a certain extent through photo-induced trans→cis isomerization, and found that the NLO performances of cis isomers of 1 and 2 exhibit SA and positive refraction and are similar to those of 1-PMMA and 2-PMMA. This work provides a new exploratory method for studying the influencing factors of third-order NLO performance.
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Affiliation(s)
- Kangshuai Geng
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 450001, Zhengzhou, P. R. China
| | - Qiong Xie
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 450001, Zhengzhou, P. R. China
| | - Yujie Zhao
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 450001, Zhengzhou, P. R. China
| | - Linpo Yang
- Department of Applied Physics, Harbin Institute of Technology, 150001, Harbin, P. R. China
| | - Yinglin Song
- Department of Applied Physics, Harbin Institute of Technology, 150001, Harbin, P. R. China
| | - Hongwei Hou
- Green Catalysis Center and College of Chemistry, Zhengzhou University, 450001, Zhengzhou, P. R. China
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6
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Wang S, Ruoko TP, Wang G, Riera-Galindo S, Hultmark S, Puttisong Y, Moro F, Yan H, Chen WM, Berggren M, Müller C, Fabiano S. Sequential Doping of Ladder-Type Conjugated Polymers for Thermally Stable n-Type Organic Conductors. ACS APPLIED MATERIALS & INTERFACES 2020; 12:53003-53011. [PMID: 33179508 PMCID: PMC7735673 DOI: 10.1021/acsami.0c16254] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/29/2020] [Indexed: 06/11/2023]
Abstract
Doping of organic semiconductors is a powerful tool to optimize the performance of various organic (opto)electronic and bioelectronic devices. Despite recent advances, the low thermal stability of the electronic properties of doped polymers still represents a significant obstacle to implementing these materials into practical applications. Hence, the development of conducting doped polymers with excellent long-term stability at elevated temperatures is highly desirable. Here, we report on the sequential doping of the ladder-type polymer poly(benzimidazobenzophenanthroline) (BBL) with a benzimidazole-based dopant (i.e., N-DMBI). By combining electrical, UV-vis/infrared, X-ray diffraction, and electron paramagnetic resonance measurements, we quantitatively characterized the conductivity, Seebeck coefficient, spin density, and microstructure of the sequentially doped polymer films as a function of the thermal annealing temperature. Importantly, we observed that the electrical conductivity of N-DMBI-doped BBL remains unchanged even after 20 h of heating at 190 °C. This finding is remarkable and of particular interest for organic thermoelectrics.
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Affiliation(s)
- Suhao Wang
- Laboratory of Organic
Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
| | - Tero-Petri Ruoko
- Laboratory of Organic
Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
| | - Gang Wang
- Laboratory of Organic
Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
| | - Sergi Riera-Galindo
- Laboratory of Organic
Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
| | - Sandra Hultmark
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Goteborg, Sweden
| | - Yuttapoom Puttisong
- Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Fabrizio Moro
- Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Hongping Yan
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, 94025 California, United States
| | - Weimin M. Chen
- Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Magnus Berggren
- Laboratory of Organic
Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Goteborg, Sweden
| | - Simone Fabiano
- Laboratory of Organic
Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
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7
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Watts KE, Neelamraju B, Moser M, McCulloch I, Ratcliff EL, Pemberton JE. Thermally Induced Formation of HF 4TCNQ - in F 4TCNQ-Doped Regioregular P3HT. J Phys Chem Lett 2020; 11:6586-6592. [PMID: 32701299 DOI: 10.1021/acs.jpclett.0c01673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The prototypical system for understanding doping in solution-processed organic electronics has been poly(3-hexylthiophene) (P3HT) p-doped with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). Multiple charge-transfer states, defined by the fraction of electron transfer to F4TCNQ, are known to coexist and are dependent on polymer molecular weight, crystallinity, and processing. Less well-understood is the loss of conductivity after thermal annealing of these materials. Specifically, in thermoelectrics, F4TCNQ-doped regioregular (rr) P3HT exhibits significant conductivity losses at temperatures lower than other thiophene-based polymers. Through detailed spectroscopic investigation of progressively heated P3HT films coprocessed with F4TCNQ, we demonstrate that this diminished conductivity is due to formation of the nonchromophoric, weak dopant HF4TCNQ-. This species is likely formed through hydrogen abstraction from the α aliphatic carbon of the hexyl chain at the 3-position of thiophene rings of rr-P3HT. This reaction is eliminated for polymers with ethylene glycol-containing side chains, which retain conductivity at higher operating temperatures. In total, these results provide a critical materials design guideline for organic electronics.
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Affiliation(s)
| | | | - Maximilian Moser
- Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London, U.K
| | - Iain McCulloch
- Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London, U.K
- KSC, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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8
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Kim Y, Broch K, Lee W, Ahn H, Lee J, Yoo D, Kim J, Chung S, Sirringhaus H, Kang K, Lee T. Highly Stable Contact Doping in Organic Field Effect Transistors by Dopant-Blockade Method. ADVANCED FUNCTIONAL MATERIALS 2020; 30:2000058. [PMID: 32684904 PMCID: PMC7357569 DOI: 10.1002/adfm.202000058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/08/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
In organic device applications, a high contact resistance between metal electrodes and organic semiconductors prevents an efficient charge injection and extraction, which fundamentally limits the device performance. Recently, various contact doping methods have been reported as an effective way to resolve the contact resistance problem. However, the contact doping has not been explored extensively in organic field effect transistors (OFETs) due to dopant diffusion problem, which significantly degrades the device stability by damaging the ON/OFF switching performance. Here, the stability of a contact doping method is improved by incorporating "dopant-blockade molecules" in the poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) film in order to suppress the diffusion of the dopant molecules. By carefully selecting the dopant-blockade molecules for effectively blocking the dopant diffusion paths, the ON/OFF ratio of PBTTT OFETs can be maintained over 2 months. This work will maximize the potential of OFETs by employing the contact doping method as a promising route toward resolving the contact resistance problem.
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Affiliation(s)
- Youngrok Kim
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Katharina Broch
- Institute for Applied PhysicsUniversity of TuebingenAuf der Morgenstelle 10Tuebingen72076Germany
| | - Woocheol Lee
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Heebeom Ahn
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Jonghoon Lee
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Daekyoung Yoo
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Junwoo Kim
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Seungjun Chung
- Photo‐Electronic Hybrids Research CenterKorea Institute of Science and TechnologySeoul02792Korea
| | - Henning Sirringhaus
- Cavendish LaboratoryUniversity of CambridgeJ. J. Thomson AvenueCambridgeCB3 0HEUK
| | - Keehoon Kang
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Takhee Lee
- Department of Physics and Astronomy and Institute of Applied PhysicsSeoul National UniversitySeoul08826Korea
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9
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Xu K, Sun H, Ruoko TP, Wang G, Kroon R, Kolhe NB, Puttisong Y, Liu X, Fazzi D, Shibata K, Yang CY, Sun N, Persson G, Yankovich AB, Olsson E, Yoshida H, Chen WM, Fahlman M, Kemerink M, Jenekhe SA, Müller C, Berggren M, Fabiano S. Ground-state electron transfer in all-polymer donor-acceptor heterojunctions. NATURE MATERIALS 2020; 19:738-744. [PMID: 32152564 DOI: 10.1038/s41563-020-0618-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Doping of organic semiconductors is crucial for the operation of organic (opto)electronic and electrochemical devices. Typically, this is achieved by adding heterogeneous dopant molecules to the polymer bulk, often resulting in poor stability and performance due to dopant sublimation or aggregation. In small-molecule donor-acceptor systems, charge transfer can yield high and stable electrical conductivities, an approach not yet explored in all-conjugated polymer systems. Here, we report ground-state electron transfer in all-polymer donor-acceptor heterojunctions. Combining low-ionization-energy polymers with high-electron-affinity counterparts yields conducting interfaces with resistivity values five to six orders of magnitude lower than the separate single-layer polymers. The large decrease in resistivity originates from two parallel quasi-two-dimensional electron and hole distributions reaching a concentration of ∼1013 cm-2. Furthermore, we transfer the concept to three-dimensional bulk heterojunctions, displaying exceptional thermal stability due to the absence of molecular dopants. Our findings hold promise for electro-active composites of potential use in, for example, thermoelectrics and wearable electronics.
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Affiliation(s)
- Kai Xu
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden
| | - Hengda Sun
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden.
| | - Tero-Petri Ruoko
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden
| | - Gang Wang
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden
| | - Renee Kroon
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Nagesh B Kolhe
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Yuttapoom Puttisong
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Xianjie Liu
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden
| | - Daniele Fazzi
- Institute of Physical Chemistry, Department Chemistry, University of Cologne, Cologne, Germany
| | - Koki Shibata
- Graduate School of Science and Engineering, Chiba University, Inage-ku, Chiba, Japan
| | - Chi-Yuan Yang
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden
| | - Ning Sun
- Department of Physics, Center for Optoelectronics Engineering Research, Yunnan University, Kunming, China
| | - Gustav Persson
- Department of Physics, Chalmers University of Technology, Göteborg, Sweden
| | - Andrew B Yankovich
- Department of Physics, Chalmers University of Technology, Göteborg, Sweden
| | - Eva Olsson
- Department of Physics, Chalmers University of Technology, Göteborg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, Göteborg, Sweden
| | - Hiroyuki Yoshida
- Graduate School of Engineering, Chiba University, Inage-ku, Chiba, Japan
- Molecular Chirality Research Center, Chiba University, Inage-ku, Chiba, Japan
| | - Weimin M Chen
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Mats Fahlman
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden
- Wallenberg Wood Science Center, Linköping University, Norrköping, Sweden
| | - Martijn Kemerink
- Complex Materials and Devices, Department of Physics Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Samson A Jenekhe
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, Göteborg, Sweden
| | - Magnus Berggren
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden.
- Wallenberg Wood Science Center, Linköping University, Norrköping, Sweden.
| | - Simone Fabiano
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, Sweden.
- Wallenberg Wood Science Center, Linköping University, Norrköping, Sweden.
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10
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Zhao W, Ding J, Zou Y, Di CA, Zhu D. Chemical doping of organic semiconductors for thermoelectric applications. Chem Soc Rev 2020; 49:7210-7228. [DOI: 10.1039/d0cs00204f] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review highlights thermoelectric-oriented chemical doping of organic semiconductors from molecular design, doping mechanisms, doping methods and insightful strategies.
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Affiliation(s)
- Wenrui Zhao
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Organic Solids
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Jiamin Ding
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Organic Solids
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Ye Zou
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Organic Solids
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Chong-an Di
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Organic Solids
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Daoben Zhu
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Organic Solids
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
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11
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Cavaye H. Neutron Spectroscopy: An Under-Utilised Tool for Organic Electronics Research? Angew Chem Int Ed Engl 2019; 58:9338-9346. [PMID: 30561867 DOI: 10.1002/anie.201812950] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Indexed: 11/08/2022]
Abstract
Neutron scattering is a well-established technique that has proven to be an invaluable tool in myriad fields of chemical and physical research. Neutrons offer unique ways to study in situ or operando functional materials due to their highly penetrating nature and specific interactions with the nuclei of different isotopes. While some neutron scattering techniques, such as neutron diffraction (ND), neutron reflectometry (NR), and small-angle neutron scattering (SANS), have already been heavily adopted by the scientific community for use in the research of organic electronics, there are a number of techniques that are far less widely used: spectroscopic neutron scattering. This article aims to highlight these "under-utilised" techniques, to emphasise their potential use within the field of organic electronics, and to increase awareness of their utility among new research communities.
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Affiliation(s)
- Hamish Cavaye
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot, OX11 0QX, UK
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12
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Cavaye H. Neutron Spectroscopy: An Under‐Utilised Tool for Organic Electronics Research? Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201812950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hamish Cavaye
- ISIS Neutron and Muon SourceRutherford Appleton LaboratoryScience and Technology Facilities Council Didcot OX11 0QX UK
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13
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Kim Y, Chung S, Cho K, Harkin D, Hwang WT, Yoo D, Kim JK, Lee W, Song Y, Ahn H, Hong Y, Sirringhaus H, Kang K, Lee T. Enhanced Charge Injection Properties of Organic Field-Effect Transistor by Molecular Implantation Doping. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806697. [PMID: 30667548 DOI: 10.1002/adma.201806697] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/13/2018] [Indexed: 06/09/2023]
Abstract
Organic semiconductors (OSCs) have been widely studied due to their merits such as mechanical flexibility, solution processability, and large-area fabrication. However, OSC devices still have to overcome contact resistance issues for better performances. Because of the Schottky contact at the metal-OSC interfaces, a non-ideal transfer curve feature often appears in the low-drain voltage region. To improve the contact properties of OSCs, there have been several methods reported, including interface treatment by self-assembled monolayers and introducing charge injection layers. Here, a selective contact doping of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4 -TCNQ) by solid-state diffusion in poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) to enhance carrier injection in bottom-gate PBTTT organic field-effect transistors (OFETs) is demonstrated. Furthermore, the effect of post-doping treatment on diffusion of F4 -TCNQ molecules in order to improve the device stability is investigated. In addition, the application of the doping technique to the low-voltage operation of PBTTT OFETs with high-k gate dielectrics demonstrated a potential for designing scalable and low-power organic devices by utilizing doping of conjugated polymers.
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Affiliation(s)
- Youngrok Kim
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Seungjun Chung
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - Kyungjune Cho
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - David Harkin
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, 0HE, UK
| | - Wang-Taek Hwang
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Daekyoung Yoo
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jae-Keun Kim
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Woocheol Lee
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Younggul Song
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Heebeom Ahn
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Yongtaek Hong
- Department of Electrical and Computer Engineering, Inter-University Semiconductor Research Center, Seoul National University, Seoul, 08826, Korea
| | - Henning Sirringhaus
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, 0HE, UK
| | - Keehoon Kang
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Takhee Lee
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
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14
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Vijayakumar V, Zaborova E, Biniek L, Zeng H, Herrmann L, Carvalho A, Boyron O, Leclerc N, Brinkmann M. Effect of Alkyl Side Chain Length on Doping Kinetics, Thermopower, and Charge Transport Properties in Highly Oriented F 4TCNQ-Doped PBTTT Films. ACS APPLIED MATERIALS & INTERFACES 2019; 11:4942-4953. [PMID: 30644706 DOI: 10.1021/acsami.8b17594] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Doping of polymer semiconductors such as poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2- b]thiophene) (PBTTT) with acceptor molecules such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) is widely used to tune the charge transport and thermoelectric (TE) properties in thin films. However, the mechanism of dopant insertion in the polymer matrix, insertion kinetics, and the ultimate doping levels reached have been investigated only marginally. This contribution addresses the effect of alkyl side chain length on the doping mechanism of a series of PBTTTs with linear side chains ranging from n-octyl to n-octyldecyl. The study focuses on thin films oriented by high-temperature rubbing and sequentially doped in F4TCNQ solution. Structure-property correlations are established as a function of side chain length by a combination of transmission electron microscopy, polarized UV-vis-NIR spectroscopy, and charge transport/thermopower measurements. Intercalation of F4TCNQ into the layers of side chains results in the expansion of the lattice along the side chains and the contraction along the π-stacking direction for all polymers. The extent of lattice expansion decreases with the increasing side chain length. UV-vis-NIR spectroscopy demonstrates integer charge transfer for all investigated PBTTTs. The doping kinetics and the final doping level depend on both the side chain length and packing. Highly disordered n-octyl and crystalline n-octyldecyl side chain layers tend to hamper dopant diffusion in the side chain layers contrary to n-dodecyl side chains that can host the highest proportion of dopants. Consequently, the best TE properties are observed for C12-PBTTT films. Alignment of the polymers significantly enhances the TE performance by increasing the charge conductivity and the thermopower along the rubbing direction. Aligned films of C12-PBTTT show charge conductivities of 193 S cm-1 along the rubbing direction and power factors of approximately 100 μW m-1 K-2 versus a few μW m-1 K-2 for nonoriented films.
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Affiliation(s)
- Vishnu Vijayakumar
- Université de Strasbourg, CNRS, ICS UPR 22 , F-67000 Strasbourg , France
| | - Elena Zaborova
- CiNaM, UMR 7325, Université Aix Marseille , Campus de Luminy, Case 913 , 13288 Marseille Cedex 9, France
- Université de Strasbourg, CNRS, ICPEES UMR 7515 , F-67087 Strasbourg , France
| | - Laure Biniek
- Université de Strasbourg, CNRS, ICS UPR 22 , F-67000 Strasbourg , France
| | - Huiyan Zeng
- Université de Strasbourg, CNRS, ICS UPR 22 , F-67000 Strasbourg , France
| | - Laurent Herrmann
- Université de Strasbourg, CNRS, ICS UPR 22 , F-67000 Strasbourg , France
| | - Alain Carvalho
- Université de Strasbourg, CNRS, ICS UPR 22 , F-67000 Strasbourg , France
| | - Olivier Boyron
- Laboratoire de Chimie Catalyse Polymères et Procédés (C2P2) , Université de Lyon 1, CPE Lyon, CNRS UMR 5265 , Bat 308F, 43 bd du 11 Novembre 1918 , 69616 Villeurbanne , France
| | - Nicolas Leclerc
- Université de Strasbourg, CNRS, ICPEES UMR 7515 , F-67087 Strasbourg , France
| | - Martin Brinkmann
- Université de Strasbourg, CNRS, ICS UPR 22 , F-67000 Strasbourg , France
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15
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He H, Kim KH, Danilov A, Montemurro D, Yu L, Park YW, Lombardi F, Bauch T, Moth-Poulsen K, Iakimov T, Yakimova R, Malmberg P, Müller C, Kubatkin S, Lara-Avila S. Uniform doping of graphene close to the Dirac point by polymer-assisted assembly of molecular dopants. Nat Commun 2018; 9:3956. [PMID: 30262825 PMCID: PMC6160407 DOI: 10.1038/s41467-018-06352-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 08/31/2018] [Indexed: 11/12/2022] Open
Abstract
Tuning the charge carrier density of two-dimensional (2D) materials by incorporating dopants into the crystal lattice is a challenging task. An attractive alternative is the surface transfer doping by adsorption of molecules on 2D crystals, which can lead to ordered molecular arrays. However, such systems, demonstrated in ultra-high vacuum conditions (UHV), are often unstable in ambient conditions. Here we show that air-stable doping of epitaxial graphene on SiC—achieved by spin-coating deposition of 2,3,5,6-tetrafluoro-tetracyano-quino-dimethane (F4TCNQ) incorporated in poly(methyl-methacrylate)—proceeds via the spontaneous accumulation of dopants at the graphene-polymer interface and by the formation of a charge-transfer complex that yields low-disorder, charge-neutral, large-area graphene with carrier mobilities ~70 000 cm2 V−1 s−1 at cryogenic temperatures. The assembly of dopants on 2D materials assisted by a polymer matrix, demonstrated by spin-coating wafer-scale substrates in ambient conditions, opens up a scalable technological route toward expanding the functionality of 2D materials. Incorporating dopants in the graphene lattice to tune its electronic properties is a challenging task. Here, the authors report a strategy to dope epitaxial large-area graphene on SiC by means of spin-coating deposition of F4TCNQ polymers in ambient conditions.
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Affiliation(s)
- Hans He
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Kyung Ho Kim
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden.,Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
| | - Andrey Danilov
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Domenico Montemurro
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Liyang Yu
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Göteborg, Sweden
| | - Yung Woo Park
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.,Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea.,Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Floriana Lombardi
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Thilo Bauch
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Kasper Moth-Poulsen
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Göteborg, Sweden
| | - Tihomir Iakimov
- Department of Physics, Chemistry and Biology, Linkoping University, 581 83, Linköping, Sweden
| | - Rositsa Yakimova
- Department of Physics, Chemistry and Biology, Linkoping University, 581 83, Linköping, Sweden
| | - Per Malmberg
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Göteborg, Sweden
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Göteborg, Sweden
| | - Sergey Kubatkin
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Samuel Lara-Avila
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96, Gothenburg, Sweden. .,National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK.
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16
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Saller C, Kahle FJ, Müller T, Hahn T, Tscheuschner S, Priadko D, Strohriegl P, Bässler H, Köhler A. Facile Method for the Investigation of Temperature-Dependent C 60 Diffusion in Conjugated Polymers. ACS APPLIED MATERIALS & INTERFACES 2018; 10:21499-21509. [PMID: 29847088 DOI: 10.1021/acsami.8b05520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We developed a novel all-optical method for monitoring the diffusion of a small quencher molecule through a polymer layer in a bilayer architecture. Experimentally, we injected C60 molecules from a C60 layer into the adjacent donor layer by stepwise heating, and we measured how the photoluminescence (PL) of the donor layer becomes gradually quenched by the incoming C60 molecules. By analyzing the temporal evolution of the PL, the diffusion coefficient of C60 can be extracted, as well as its activation energy and an approximate concentration profile in the film. We applied this technique to three carbazole-based low-bandgap polymers with different glass temperatures with a view to study the impact of structural changes of the polymer matrix on the diffusion process. We find that C60 diffusion is thermally activated and not driven by WFL-type collective motion above Tg but rather by local motions mediated by the sidechains. The results are useful as guidance for material design and device engineering, and the approach can be adapted to a wide range of donor and acceptor materials.
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17
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Nakano K, Shibamori T, Tajima K. Quantitative Evaluation of Molecular Diffusion in Organic Planar Heterojunctions by Time-of-Flight Secondary Ion Mass Spectroscopy. ACS OMEGA 2018; 3:1522-1528. [PMID: 31458477 PMCID: PMC6641331 DOI: 10.1021/acsomega.7b01524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/22/2017] [Indexed: 06/08/2023]
Abstract
Understanding molecular diffusion across the interfaces in planar heterojunctions is fundamentally important to improving the performance and stability of organic electronic devices. In this study, we quantitatively evaluated the diffusion of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) across the interface of planar heterojunctions into the polymer layers by time-of-flight secondary ion mass spectroscopy. Careful calibration allowed the concentration of PCBM to be determined in the polymer layer at concentrations as low as 0.01 wt %. We found that approximately 1 wt % PCBM was present in the poly(3-hexylthiophene) layer in the planar heterojunction with no thermal treatments, indicating that a small amount of PCBM diffused into the polymer layer even at room temperature. The diffusion behavior depended strongly on the crystallinity of the PCBM layer and the properties of the polymer layers such as glass transition temperature. Further analysis suggested that the diffusion of PCBM into the polymer layers was also related to the interface free energy between the layers.
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Affiliation(s)
- Kyohei Nakano
- RIKEN
Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takahiro Shibamori
- TORAY
Research Center, Inc., 3-3-7, Sonoyama, Otsu, Shiga 520-8567, Japan
| | - Keisuke Tajima
- RIKEN
Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Precursory
Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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18
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Jacobs IE, Moulé AJ. Controlling Molecular Doping in Organic Semiconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703063. [PMID: 28921668 DOI: 10.1002/adma.201703063] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/24/2017] [Indexed: 05/23/2023]
Abstract
The field of organic electronics thrives on the hope of enabling low-cost, solution-processed electronic devices with mechanical, optoelectronic, and chemical properties not available from inorganic semiconductors. A key to the success of these aspirations is the ability to controllably dope organic semiconductors with high spatial resolution. Here, recent progress in molecular doping of organic semiconductors is summarized, with an emphasis on solution-processed p-type doped polymeric semiconductors. Highlighted topics include how solution-processing techniques can control the distribution, diffusion, and density of dopants within the organic semiconductor, and, in turn, affect the electronic properties of the material. Research in these areas has recently intensified, thanks to advances in chemical synthesis, improved understanding of charged states in organic materials, and a focus on relating fabrication techniques to morphology. Significant disorder in these systems, along with complex interactions between doping and film morphology, is often responsible for charge trapping and low doping efficiency. However, the strong coupling between doping, solubility, and morphology can be harnessed to control crystallinity, create doping gradients, and pattern polymers. These breakthroughs suggest a role for molecular doping not only in device function but also in fabrication-applications beyond those directly analogous to inorganic doping.
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Affiliation(s)
- Ian E Jacobs
- Department of Materials Science, University of California, Davis, 1 Shields Avenue, Davis, CA, 95616, USA
| | - Adam J Moulé
- Department of Chemical Engineering, University of California, Davis, 1 Shields Avenue, Davis, CA, 95616, USA
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