1
|
Zhao W, Fu GE, Yang H, Zhang T. Two-Dimensional Conjugated Polymers: a New Choice For Organic Thin-Film Transistors. Chem Asian J 2023:e202301076. [PMID: 38151907 DOI: 10.1002/asia.202301076] [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: 11/30/2023] [Revised: 12/19/2023] [Accepted: 12/25/2023] [Indexed: 12/29/2023]
Abstract
Organic thin-film transistors (OTFTs) as a vital component among transistors have shown great potential in smart sensing, flexible displays, and bionics due to their flexibility, biocompatibility and customizable chemical structures. Even though linear conjugated polymer semiconductors are common for constructing channel materials of OTFTs, advanced materials with high charge carrier mobility, tunable band structure, robust stability, and clear structure-property relationship are indispensable for propelling the evolution of OTFTs. Two-dimensional conjugated polymers (2DCPs), featured with conjugated lattice, tailorable skeletons, and functional porous structures, match aforementioned criteria closely. In this review, we firstly introduce the synthesis of 2DCP thin films, focusing on their characteristics compatible with the channels of OTFTs. Subsequently, the physics and operating mechanisms of OTFTs and the applications of 2DCPs in OTFTs are summarized in detail. Finally, the outlook and perspective in the field of OTFTs using 2DCPs are provided as well.
Collapse
Affiliation(s)
- Wenkai Zhao
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Key Laboratory of Marine Materials and Related Technologies, 315201, Ningbo, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Guang-En Fu
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Key Laboratory of Marine Materials and Related Technologies, 315201, Ningbo, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Haoyong Yang
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Key Laboratory of Marine Materials and Related Technologies, 315201, Ningbo, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Tao Zhang
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Key Laboratory of Marine Materials and Related Technologies, 315201, Ningbo, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Saeedifard F, Chang YC, Kippelen B, Marder SR, Barlow S. Thermal Insolubilization of Electrically n-Doped Films Achieved Using 7-Alkoxy-Benzocyclobutene-Substituted Fullerene and Dopant Molecules. J Phys Chem B 2022; 126:8094-8101. [PMID: 36170664 DOI: 10.1021/acs.jpcb.2c05286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Insoluble electrically n-doped fullerene-containing films have been obtained by thermal annealing of a fullerene compound and a 1,3-dimethyl-2,3-dihydro-1H-benzo[d]imidazole n-dopant moiety, both of which are functionalized with a 7-butoxybenzocyclobutene group. The covalent tethering and electrical doping reactions are studied by mass spectrometry as well as electron paramagnetic resonance. Optical absorption spectra on BBCB-N-DMBI-H-doped BBCBP indicate films heated at 150 °C for 10 min are unaffected by immersion for 10 min in ortho-dichlorobenzene. Although films containing a 10 mol % loading of the dopant showed electrical conductivity values of 1.1 × 10-5 ± 3.4 × 10-7 S cm-1 prior to heating, the thermal insolubilization process led to values around two orders-of-magnitude lower. However, the thermal insolubilization also leads to immobilization of the dopant molecule and the corresponding cation, reducing their ability to diffuse into an adjacent layer of a stronger electron acceptor.
Collapse
Affiliation(s)
- Farzaneh Saeedifard
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.,Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Yi-Chien Chang
- School of Electrical and Computer Engineering, Center for Organic Photonics and Electronics (COPE), Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Bernard Kippelen
- School of Electrical and Computer Engineering, Center for Organic Photonics and Electronics (COPE), Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Seth R Marder
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.,Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States.,Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States.,Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80303, United States.,Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Stephen Barlow
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.,Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
| |
Collapse
|
4
|
Wang X, Li J, Dong C, Zhang L, Hu J, Liu J, Liu Y. n-Type thermoelectric properties of a doped organoboron polymer. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
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: 57] [Impact Index Per Article: 19.0] [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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Sakai N, Warren R, Zhang F, Nayak S, Liu J, Kesava SV, Lin YH, Biswal HS, Lin X, Grovenor C, Malinauskas T, Basu A, Anthopoulos TD, Getautis V, Kahn A, Riede M, Nayak PK, Snaith HJ. Adduct-based p-doping of organic semiconductors. NATURE MATERIALS 2021; 20:1248-1254. [PMID: 33888905 DOI: 10.1038/s41563-021-00980-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
Electronic doping of organic semiconductors is essential for their usage in highly efficient optoelectronic devices. Although molecular and metal complex-based dopants have already enabled significant progress of devices based on organic semiconductors, there remains a need for clean, efficient and low-cost dopants if a widespread transition towards larger-area organic electronic devices is to occur. Here we report dimethyl sulfoxide adducts as p-dopants that fulfil these conditions for a range of organic semiconductors. These adduct-based dopants are compatible with both solution and vapour-phase processing. We explore the doping mechanism and use the knowledge we gain to 'decouple' the dopants from the choice of counterion. We demonstrate that asymmetric p-doping is possible using solution processing routes, and demonstrate its use in metal halide perovskite solar cells, organic thin-film transistors and organic light-emitting diodes, which showcases the versatility of this doping approach.
Collapse
Affiliation(s)
- Nobuya Sakai
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Ross Warren
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Fengyu Zhang
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
| | - Simantini Nayak
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, Oxford, UK
- Materials Chemistry Department, CSIR-Institute of Mineral and Materials Technology, Bhubaneswar, India
| | - Junliang Liu
- Department of Materials, University of Oxford, Oxford, UK
| | - Sameer V Kesava
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Yen-Hung Lin
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Himansu S Biswal
- School of Chemical Sciences, National Institute of Science Education and Research, Bhubaneswar, India
| | - Xin Lin
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
| | - Chris Grovenor
- Department of Materials, University of Oxford, Oxford, UK
| | - Tadas Malinauskas
- Department of Organic Chemistry, Kaunas University of Technology, Kaunas, Lithuania
| | - Aniruddha Basu
- KAUST Solar Center (KSC), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Thomas D Anthopoulos
- KAUST Solar Center (KSC), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Vytautas Getautis
- Department of Organic Chemistry, Kaunas University of Technology, Kaunas, Lithuania
| | - Antoine Kahn
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
| | - Moritz Riede
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Pabitra K Nayak
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, India.
| | - Henry J Snaith
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Liu S, Radha Krishnan RK, Dahal D, Lüssem B. Analytic Device Model of Organic Field-Effect Transistors with Doped Channels. ACS APPLIED MATERIALS & INTERFACES 2020; 12:49857-49865. [PMID: 33103885 DOI: 10.1021/acsami.0c12534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Doping has been shown to not only provide additional degrees of freedom in the design of organic field-effect transistors (OFETs) but to increase their performance and stability as well. An analytical model based on the assumption of a square doping profile inside the channel is presented here that describes the effect of doping on the transfer characteristic of OFETs. The model is validated experimentally by a series of OFETs with varying doping conditions. The precise doping profile in the transistor channel is determined by fitting the capacitance/voltage response of doped metal-insulator-semiconductor (MIS) junctions using an AC small-signal drift-diffusion simulation. It is shown that the real doping profile deviates from the simplifying assumptions of the analytical model, i.e., it is found that the effective doping concentration at the dielectric/semiconductor interface is reduced. However, it is shown that the analytical model is not sensitive to this deviation as only the total density charges per unit area determine the changes in the transistor behavior. Overall, the presented theory provides new design rules that can be used to guide the development of doped OFETs with high performance.
Collapse
Affiliation(s)
- Shiyi Liu
- Department of Physics, Kent State University, Kent, Ohio 44240, United States
| | | | - Drona Dahal
- Department of Physics, Kent State University, Kent, Ohio 44240, United States
| | - Björn Lüssem
- Department of Physics, Kent State University, Kent, Ohio 44240, United States
| |
Collapse
|
10
|
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.
Collapse
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
| | | | | |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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: 41] [Impact Index Per Article: 10.3] [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.
Collapse
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.
| |
Collapse
|
13
|
Babuji A, Temiño I, Pérez-Rodríguez A, Solomeshch O, Tessler N, Vila M, Li J, Mas-Torrent M, Ocal C, Barrena E. Double Beneficial Role of Fluorinated Fullerene Dopants on Organic Thin-Film Transistors: Structural Stability and Improved Performance. ACS APPLIED MATERIALS & INTERFACES 2020; 12:28416-28425. [PMID: 32460481 DOI: 10.1021/acsami.0c06418] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The present work assesses improved carrier injection in organic field-effect transistors by contact doping and provides fundamental insight into the multiple impacts that the dopant/semiconductor interface details have on the long-term and thermal stability of devices. We investigate donor [1]benzothieno[3,2-b]-[1]benzothiophene (BTBT) derivatives with one and two octyl side chains attached to the core, therefore constituting asymmetric (BTBT-C8) and symmetric (C8-BTBT-C8) molecules, respectively. Our results reveal that films formed out of the asymmetric BTBT-C8 expose the same alkyl-terminated surface as the C8-BTBT-C8 films do. In both cases, the consequence of depositing fluorinated fullerene (C60F48) as a molecular p-dopant is the formation of C60F48 crystalline islands decorating the step edges of the underlying semiconductor film surface. We demonstrate that local work function changes along with a peculiar nanomorphology lead to the double beneficial effect of lowering the contact resistance and providing long-term and enhanced thermal stability of the devices.
Collapse
Affiliation(s)
- Adara Babuji
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
| | - Inés Temiño
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
| | - Ana Pérez-Rodríguez
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
| | - Olga Solomeshch
- Electrical Engineering Department, Nanoelectronic Center, Technion, 32000 Haifa, Israel
| | - Nir Tessler
- Electrical Engineering Department, Nanoelectronic Center, Technion, 32000 Haifa, Israel
| | - Maria Vila
- SpLine CRG BM25 Beamline, European Synchrotron Radiation Facility, 71, Avenue des Martyrs, 38000 Grenoble, France
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), 28049 Madrid, Spain
| | - Jinghai Li
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
| | - Marta Mas-Torrent
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
- CIBER-BBN, Campus UAB, 08193 Bellaterra, Spain
| | - Carmen Ocal
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
| | - Esther Barrena
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), 08193 Bellaterra, Barcelona, Spain
| |
Collapse
|
14
|
Silvestri F, Prieto MJ, Babuji A, Tănase LC, de Souza Caldas L, Solomeshch O, Schmidt T, Ocal C, Barrena E. Impact of Nanomorphology on Surface Doping of Organic Semiconductors: The Pentacene-C 60F 48 Interface. ACS APPLIED MATERIALS & INTERFACES 2020; 12:25444-25452. [PMID: 32388975 DOI: 10.1021/acsami.0c05583] [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
Establishing the rather complex correlation between the structure and the charge transfer in organic-organic heterostructures is of utmost importance for organic electronics and requires spatially resolved structural, chemical, and electronic details. Insight into this issue is provided here by combining atomic force microscopy, Kelvin probe force microscopy, photoemission electron microscopy, and low-energy electron microscopy for investigating a case study. We select the interface formed by pentacene (PEN), benchmark among the donor organic semiconductors, and a p-type dopant from the family of fluorinated fullerenes. As for Buckminsterfullerene (C60), the growth of its fluorinated derivative C60F48 is influenced by the thickness and crystallinity of the PEN buffer layer, but the behavior is markedly different. We provide a microscopic description of the C60F48/PEN interface formation and analyze the consequences in the electronic properties of the final heterostructure. For just one single layer of PEN, a laterally complete but noncompact C60F48/PEN interface is created, importantly affecting the surface work function. Nonetheless, from the very beginning of the second layer formation, the presence of epitaxial and nonepitaxial PEN domains dramatically influences the growth dynamics and extremely well packed two-dimensional C60F48 islands develop. Insightful elemental maps of the C60F48/PEN surface spatially resolve the nonuniform distribution of the dopant molecules, which leads to a heterogeneous work function landscape.
Collapse
Affiliation(s)
- Francesco Silvestri
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Bellaterra, 08193 Barcelona, Spain
| | - Mauricio J Prieto
- Department of Interface Science, Fritz-Haber Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Adara Babuji
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Bellaterra, 08193 Barcelona, Spain
| | - Liviu C Tănase
- Department of Interface Science, Fritz-Haber Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Lucas de Souza Caldas
- Department of Interface Science, Fritz-Haber Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Olga Solomeshch
- Electrical Engineering Department, Nanoelectronic Center, Technion, Haifa 32000, Israel
| | - Thomas Schmidt
- Department of Interface Science, Fritz-Haber Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Carmen Ocal
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Bellaterra, 08193 Barcelona, Spain
| | - Esther Barrena
- Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Bellaterra, 08193 Barcelona, Spain
| |
Collapse
|
15
|
Zapata-Arteaga O, Dörling B, Perevedentsev A, Martín J, Reparaz JS, Campoy-Quiles M. Closing the Stability-Performance Gap in Organic Thermoelectrics by Adjusting the Partial to Integer Charge Transfer Ratio. Macromolecules 2020; 53:609-620. [PMID: 32089566 PMCID: PMC7032849 DOI: 10.1021/acs.macromol.9b02263] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/17/2019] [Indexed: 12/25/2022]
Abstract
Two doping mechanisms are known for the well-studied materials poly(3-hexylthiophene) (P3HT) and poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT), namely, integer charge transfer (ICT) and charge transfer complex (CTC) formation. Yet, there is poor understanding of the effect of doping mechanism on thermal stability and the thermoelectric properties. In this work, we present a method to finely adjust the ICT to CTC ratio. Using it, we characterize electrical and thermal conductivities as well as the Seebeck coefficient and the long-term stability under thermal stress of P3HT and PBTTT of different ICT/CTC ratios. We establish that doping through the CTC results in more stable, yet lower conductivity samples compared to ICT doped films. Importantly, moderate CTC fractions of ∼33% are found to improve the long-term stability without a significant sacrifice in electrical conductivity. Through visible and IR spectroscopies, polarized optical microscopy, and grazing-incidence wide-angle X-ray scattering, we find that the CTC dopant molecule access sites within the polymer network are less prone to dedoping upon thermal exposure.
Collapse
Affiliation(s)
- Osnat Zapata-Arteaga
- Institute
of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| | - Bernhard Dörling
- Institute
of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| | - Aleksandr Perevedentsev
- Institute
of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| | - Jaime Martín
- POLYMAT
and Polymer Science and Technology Department, Faculty of Chemistry, University of the Basque Country UPV/EHU, Manuel de Lardizabal 3, 20018 Donostia-San Sebastián, Spain
- Ikerbasque,
Basque Foundation for Science, E-48011 Bilbao, Spain
| | - J. Sebastian Reparaz
- Institute
of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| | - Mariano Campoy-Quiles
- Institute
of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| |
Collapse
|
16
|
Kim H, Lee W, Moon H, Kim SJ, Chung HK, Chae H. Interlayer doping with p-type dopant for charge balance in indium phosphide (InP)-based quantum dot light-emitting diodes. OPTICS EXPRESS 2019; 27:A1287-A1296. [PMID: 31510582 DOI: 10.1364/oe.27.0a1287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/14/2019] [Indexed: 06/10/2023]
Abstract
A 2,3,4,6-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4-TCNQ) doping interlayer was developed to improve charge imbalance and the efficiency in indium phosphide (InP)-based quantum dot light-emitting diodes (QLEDs). The doping layer was coated between a hole injecting layer (HIL) and a hole transport layer (HTL) and successfully diffused with thermal annealing. This doping reduces the hole injection barrier and improves the charge balance of InP-based QLEDs, resulting in enhancement of an external quantum efficiency (EQE) of 3.78% (up from 1.6%) and a power efficiency of 6.41 lm/W (up from 2.77 lm/W). This work shows that F4-TCNQ interlayer doping into both HIL and HTL facilitates hole injection and can provide an efficient solution of improving charge balance in QLED for the device efficiency.
Collapse
|
17
|
Chen MT, Hofmann OT, Gerlach A, Bröker B, Bürker C, Niederhausen J, Hosokai T, Zegenhagen J, Vollmer A, Rieger R, Müllen K, Schreiber F, Salzmann I, Koch N, Zojer E, Duhm S. Energy-level alignment at strongly coupled organic-metal interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:194002. [PMID: 30673641 DOI: 10.1088/1361-648x/ab0171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Energy-level alignment at organic-metal interfaces plays a crucial role for the performance of organic electronic devices. However, reliable models to predict energetics at strongly coupled interfaces are still lacking. We elucidate contact formation of 1,2,5,6,9,10-coronenehexone (COHON) to the (1 1 1)-surfaces of coinage metals by means of ultraviolet photoelectron spectroscopy, x-ray photoelectron spectroscopy, the x-ray standing wave technique, and density functional theory calculations. While for low COHON thicknesses, the work-functions of the systems vary considerably, for thicker organic films Fermi-level pinning leads to identical work functions of 5.2 eV for all COHON-covered metals irrespective of the pristine substrate work function and the interfacial interaction strength.
Collapse
Affiliation(s)
- 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, 199 Ren-Ai Road, Suzhou 215123, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Thussing S, Fernández L, Jakob P. Thermal stability and interlayer exchange processes in heterolayers of TiOPc and PTCDA on Ag(1 1 1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:134002. [PMID: 30625431 DOI: 10.1088/1361-648x/aafcf8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Organic-organic interfaces, in particular donor-acceptor type heterointerfaces, represent central elements of organic electronic devices. Understanding and controlling their physical properties is key to improve and modify their performance. For this purpose we have investigated the structural properties and thermal evolution of molecular heterointerface model systems. Specifically, various stacked titanyl-phthalocyanine (TiOPc)-3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) heterolayers grown on Ag(1 1 1) have been examined using Fourier transform infrared absorption spectroscopy and spot-profile analysis low-energy electron diffraction. An accurate description of the thermal evolution and prevalence of the various phases of TiOPc and PTCDA is derived from the spectral signatures of the two molecular species explored in previous studies. Exceptionally high thermal stability is found for stacked heterolayers comprising TiOPc double layers with characteristic up-down arrangement of its axial Ti-O unit and single layers of PTCDA. Thereby, interlayer exchange is negligible in a wide temperature range ([Formula: see text] K). This is ascribed to attractive intermolecular interaction (dipole-dipole interaction, hydrogen bonding) among the TiOPc molecules oriented face-to-face within the TiOPc bilayer sheet. Stacked layers of comprising single layers of TiOPc and of PTCDA turn out to be thermally much less stable and more heterogeneous. In the course of their thermal evolution, a number of processes such as interlayer exchange, TiOPc double-layer formation and dewetting are encountered.
Collapse
Affiliation(s)
- S Thussing
- Fachbereich Physik und Wissenschaftliches Zentrum für Materialwissenschaften der Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | | | | |
Collapse
|
19
|
Zhang S, Moudgil K, Jucov E, Risko C, Timofeeva TV, Marder SR, Barlow S. Organometallic hydride-transfer agents as reductants for organic semiconductor molecules. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
20
|
Jang HJ, Wagner J, Li H, Zhang Q, Mukhopadhyaya T, Katz HE. Analytical Platform To Characterize Dopant Solution Concentrations, Charge Carrier Densities in Films and Interfaces, and Physical Diffusion in Polymers Utilizing Remote Field-Effect Transistors. J Am Chem Soc 2019; 141:4861-4869. [PMID: 30816046 DOI: 10.1021/jacs.8b13026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Characterizing doping effects in a conductive polymer and physical diffusion in a passive polymer were performed using a remote-gate field-effect transistor (RG FET) detection system that was able to measure the electrical potential perturbation of a polymer film coupled to the gate of a silicon FET. Poly(3-hexylthiophene) (P3HT) film doped using various concentrations of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) solutions imposed additional positive potentials on the P3HT RG, resulting in a lower threshold voltage ( Vth) on the n-channel silicon FET. Changes in Vth were related to the induced hole concentrations and hole mobility in P3HT films by using our Vth shifting model for the RG FET. We discovered that the electron-donating P3HT and even inorganic materials, indium tin oxide and gold, showed similar electrical potential perturbations dependent on the concentration of F4TCNQ in overlying solutions as the dopant radical anions maximally covered the surfaces. This suggests that there are limited electroactive sites for F4TCNQ binding on electron donor surfaces which results in a similar number of positive charges in film materials forming dipoles with the F4TCNQ radical counteranions. The effect of electron acceptors such as 7,7,8,8-tetracyanoquinodimethane and tetracyanoethylene was compared to that of F4TCNQ in terms of Vth shift using our analytical tool, with differences attributed to acceptor size and reduction potential. Meanwhile, this FET analysis tool offered a means of monitoring the physical diffusion of small molecules, exemplified by F4TCNQ, in the passive polymer polystyrene, driven by concentration gradients. The technique allows for nondestructive, nonspectroscopic, ambient characterization of electron donor-acceptor interactions at surfaces.
Collapse
Affiliation(s)
- Hyun-June Jang
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Justine Wagner
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Hui Li
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Qingyang Zhang
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Tushita Mukhopadhyaya
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Howard E. Katz
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| |
Collapse
|
21
|
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: 9] [Impact Index Per Article: 1.8] [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.
Collapse
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
| |
Collapse
|
22
|
Karpov Y, Kiriy N, Formanek P, Zessin J, Hambsch M, Mannsfeld SCB, Lissel F, Beryozkina T, Bakulev V, Voit B, Kiriy A. Layer-by-Layer Assembly Enabled by the Anionic p-Dopant CN6-CP •-K +: a Route to Achieve Interfacial Doping of Organic Semiconductors. ACS APPLIED MATERIALS & INTERFACES 2019; 11:4159-4168. [PMID: 30608639 DOI: 10.1021/acsami.8b15033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Highly efficient 2D (interfacial) doping of organic semiconductors, poly(3-hexylthiophene) (P3HT) and TIPS-pentacene, was achieved by a polyelectrolyte-supported layer-by-layer assembly of the dual-mode functional dopant CN6-CP•-K+, having an anionic group for its fixation onto oppositely charged surfaces/molecules as well as electron-deficient groups providing its p-doping ability. Polyelectrolyte-supported dopant layers were used to generate conductive channels at the bottom or at the top of semiconducting films. Unlike to the case of sequentially processed P3HT films doped by F4TCNQ ( Moulé , J. Chem. Mater. 2015 , 27 , 5765 ; Koech , P. K. J. Mater. Chem. C 2013 , 1 , 1876 ; Schwartz , B. J. J. Phys. Chem. Lett. 2015 , 6 , 4786 ), the use of more polar CN6-CP•-K+ dopant and ultrathin polycation separation interlayer enables predominantly interfacial kind of doping placement with no or minimal intercalation of the dopant into the semiconductor bulk. The layered structure of the doped film was proved by transmission electron microscopy of the cross-section and it agrees well with other data obtained in this work. The interfacial doping enabled an impressive conductivity of 13 S/cm even for ultrathin P3HT films. We propose to explain the superior efficiency of the interfacial doping compared to the bulk doping in terms of unperturbed morphology of the semiconductor and high mobility of charge carriers, which are spatially separated from the dopant phase.
Collapse
Affiliation(s)
- Yevhen Karpov
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
| | - Nataliya Kiriy
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
| | - Petr Formanek
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
| | - Jakob Zessin
- Center for Advancing Electronics Dresden (cfaed) , Technische Universität Dresden , Dresden 01062 , Germany
| | - Mike Hambsch
- Center for Advancing Electronics Dresden (cfaed) , Technische Universität Dresden , Dresden 01062 , Germany
| | - Stefan C B Mannsfeld
- Center for Advancing Electronics Dresden (cfaed) , Technische Universität Dresden , Dresden 01062 , Germany
| | - Franziska Lissel
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
| | - Tetyana Beryozkina
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
- TOSLab , Ural Federal University named after the first President of Russia B.N.Yeltsin , Mira str., 28 , 620002 Yekaterinburg , Russia
| | - Vasiliy Bakulev
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
- TOSLab , Ural Federal University named after the first President of Russia B.N.Yeltsin , Mira str., 28 , 620002 Yekaterinburg , Russia
| | - Brigitte Voit
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
- Center for Advancing Electronics Dresden (cfaed) , Technische Universität Dresden , Dresden 01062 , Germany
| | - Anton Kiriy
- Leibniz Institute of Polymer Research Dresden , Hohe Straße 6 , 01069 Dresden , Germany
| |
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
Liu Y, Cole MD, Jiang Y, Kim PY, Nordlund D, Emrick T, Russell TP. Chemical and Morphological Control of Interfacial Self-Doping for Efficient Organic Electronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1705976. [PMID: 29504157 DOI: 10.1002/adma.201705976] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/27/2017] [Indexed: 06/08/2023]
Abstract
Solution-based processing of materials for electrical doping of organic semiconductor interfaces is attractive for boosting the efficiency of organic electronic devices with multilayer structures. To simplify this process, self-doping perylene diimide (PDI)-based ionene polymers are synthesized, in which the semiconductor PDI components are embedded together with electrolyte dopants in the polymer backbone. Functionality contained within the PDI monomers suppresses their aggregation, affording self-doping interlayers with controllable thickness when processed from solution into organic photovoltaic devices (OPVs). Optimal results for interfacial self-doping lead to increased power conversion efficiencies (PCEs) of the fullerene-based OPVs, from 2.62% to 10.64%, and of the nonfullerene-based OPVs, from 3.34% to 10.59%. These PDI-ionene interlayers enable chemical and morphological control of interfacial doping and conductivity, demonstrating that the conductive channels are crucial for charge transport in doped organic semiconductor films. Using these novel interlayers with efficient doping and high conductivity, both fullerene- and nonfullerene-based OPVs are achieved with PCEs exceeding 9% over interlayer thicknesses ranging from ≈3 to 40 nm.
Collapse
Affiliation(s)
- Yao Liu
- Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, MA, 01003, USA
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Marcus D Cole
- Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, MA, 01003, USA
| | - Yufeng Jiang
- Materials Sciences Division, Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Paul Y Kim
- Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, MA, 01003, USA
| | - Dennis Nordlund
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Todd Emrick
- Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, MA, 01003, USA
| | - Thomas P Russell
- Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, MA, 01003, USA
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| |
Collapse
|
25
|
Tietze ML, Benduhn J, Pahner P, Nell B, Schwarze M, Kleemann H, Krammer M, Zojer K, Vandewal K, Leo K. Elementary steps in electrical doping of organic semiconductors. Nat Commun 2018; 9:1182. [PMID: 29563497 PMCID: PMC5862893 DOI: 10.1038/s41467-018-03302-z] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/29/2018] [Indexed: 11/12/2022] Open
Abstract
Fermi level control by doping is established since decades in inorganic semiconductors and has been successfully introduced in organic semiconductors. Despite its commercial success in the multi-billion OLED display business, molecular doping is little understood, with its elementary steps controversially discussed and mostly-empirical-materials design. Particularly puzzling is the efficient carrier release, despite a presumably large Coulomb barrier. Here we quantitatively investigate doping as a two-step process, involving single-electron transfer from donor to acceptor molecules and subsequent dissociation of the ground-state integer-charge transfer complex (ICTC). We show that carrier release by ICTC dissociation has an activation energy of only a few tens of meV, despite a Coulomb binding of several 100 meV. We resolve this discrepancy by taking energetic disorder into account. The overall doping process is explained by an extended semiconductor model in which occupation of ICTCs causes the classically known reserve regime at device-relevant doping concentrations. Molecular doping is routinely used in organic semiconductor devices nowadays, but the physics at play remains unclarified. Tietze et al. describe it as a two-step process and show it costs little, energetically, to dissociate charge transfer complexes due to energetic disorder of organic semiconductors.
Collapse
Affiliation(s)
- Max L Tietze
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany. .,Physical Science and Engineering Division, KAUST Solar Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia. .,Department of Microbial and Molecular Systems, Centre for Surface Chemistry and Catalysis, KU Leuven-University of Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium.
| | - Johannes Benduhn
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Paul Pahner
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Bernhard Nell
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Martin Schwarze
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Hans Kleemann
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Markus Krammer
- NAWI Graz, Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010, Graz, Austria
| | - Karin Zojer
- NAWI Graz, Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010, Graz, Austria
| | - Koen Vandewal
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany.,Instituut voor Materiaalonderzoek, Hasselt University, Wetenschapspark 1, 3590, Diepenbeek, Belgium
| | - Karl Leo
- Dresden Integrated Center for Applied Physics and Photonic Materials, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany.
| |
Collapse
|
26
|
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: 177] [Impact Index Per Article: 25.3] [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.
Collapse
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
| |
Collapse
|
27
|
Müller L, Rhim SY, Sivanesan V, Wang D, Hietzschold S, Reiser P, Mankel E, Beck S, Barlow S, Marder SR, Pucci A, Kowalsky W, Lovrincic R. Electric-Field-Controlled Dopant Distribution in Organic Semiconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1701466. [PMID: 28585293 DOI: 10.1002/adma.201701466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/24/2017] [Indexed: 06/07/2023]
Abstract
Stable electrical doping of organic semiconductors is fundamental for the functionality of high performance devices. It is known that dopants can be subjected to strong diffusion in certain organic semiconductors. This work studies the impact of operating conditions on thin films of the polymer poly(3-hexylthiophene) (P3HT) and the small molecule Spiro-MeOTAD, doped with two differently sized p-type dopants. The negatively charged dopants can drift upon application of an electric field in thin films of doped P3HT over surprisingly large distances. This drift is not observed in the small molecule Spiro-MeOTAD. Upon the dopants' directional movement in P3HT, a dedoped region forms at the negatively biased electrode, increasing the overall resistance of the thin film. In addition to electrical measurements, optical microscopy, spatially resolved infrared spectroscopy, and scanning Kelvin probe microscopy are used to investigate the drift of dopants. Dopant mobilities of 10-9 to 10-8 cm2 V-1 s-1 are estimated. This drift over several micrometers is reversible and can be controlled. Furthermore, this study presents a novel memory device to illustrate the applicability of this effect. The results emphasize the importance of dynamic processes under operating conditions that must be considered even for single doped layers.
Collapse
Affiliation(s)
- Lars Müller
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Institute for High-Frequency Technology, TU Braunschweig, Schleinitzstr. 22, 38106, Braunschweig, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Seon-Young Rhim
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Vipilan Sivanesan
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Dongxiang Wang
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131, Karlsruhe, Germany
| | - Sebastian Hietzschold
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Institute for High-Frequency Technology, TU Braunschweig, Schleinitzstr. 22, 38106, Braunschweig, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Patrick Reiser
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Materials Science Department, Surface Science Division, TU Darmstadt, Jovanka-Bontschits-Str. 2, 64287, Darmstadt, Germany
| | - Eric Mankel
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Materials Science Department, Surface Science Division, TU Darmstadt, Jovanka-Bontschits-Str. 2, 64287, Darmstadt, Germany
| | - Sebastian Beck
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Stephen Barlow
- Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Seth R Marder
- Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Annemarie Pucci
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
- Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Wolfgang Kowalsky
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Institute for High-Frequency Technology, TU Braunschweig, Schleinitzstr. 22, 38106, Braunschweig, Germany
- Kirchhoff Institute for Physics, Heidelberg University, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Robert Lovrincic
- InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
- Institute for High-Frequency Technology, TU Braunschweig, Schleinitzstr. 22, 38106, Braunschweig, Germany
| |
Collapse
|
28
|
Li J, Koshnick C, Diallo SO, Ackling S, Huang DM, Jacobs IE, Harrelson TF, Hong K, Zhang G, Beckett J, Mascal M, Moulé AJ. Quantitative Measurements of the Temperature-Dependent Microscopic and Macroscopic Dynamics of a Molecular Dopant in a Conjugated Polymer. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00672] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | | | | | - Sophia Ackling
- Department
of Chemistry, School of Physical Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | - David M. Huang
- Department
of Chemistry, School of Physical Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Patel SN, Glaudell AM, Peterson KA, Thomas EM, O’Hara KA, Lim E, Chabinyc ML. Morphology controls the thermoelectric power factor of a doped semiconducting polymer. SCIENCE ADVANCES 2017; 3:e1700434. [PMID: 28630931 PMCID: PMC5473677 DOI: 10.1126/sciadv.1700434] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/28/2017] [Indexed: 05/15/2023]
Abstract
The electrical performance of doped semiconducting polymers is strongly governed by processing methods and underlying thin-film microstructure. We report on the influence of different doping methods (solution versus vapor) on the thermoelectric power factor (PF) of PBTTT molecularly p-doped with F n TCNQ (n = 2 or 4). The vapor-doped films have more than two orders of magnitude higher electronic conductivity (σ) relative to solution-doped films. On the basis of resonant soft x-ray scattering, vapor-doped samples are shown to have a large orientational correlation length (OCL) (that is, length scale of aligned backbones) that correlates to a high apparent charge carrier mobility (μ). The Seebeck coefficient (α) is largely independent of OCL. This reveals that, unlike σ, leveraging strategies to improve μ have a smaller impact on α. Our best-performing sample with the largest OCL, vapor-doped PBTTT:F4TCNQ thin film, has a σ of 670 S/cm and an α of 42 μV/K, which translates to a large PF of 120 μW m-1 K-2. In addition, despite the unfavorable offset for charge transfer, doping by F2TCNQ also leads to a large PF of 70 μW m-1 K-2, which reveals the potential utility of weak molecular dopants. Overall, our work introduces important general processing guidelines for the continued development of doped semiconducting polymers for thermoelectrics.
Collapse
Affiliation(s)
- Shrayesh N. Patel
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Anne M. Glaudell
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Kelly A. Peterson
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Elayne M. Thomas
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Kathryn A. O’Hara
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Eunhee Lim
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | | |
Collapse
|
30
|
Kolesov VA, Fuentes-Hernandez C, Chou WF, Aizawa N, Larrain FA, Wang M, Perrotta A, Choi S, Graham S, Bazan GC, Nguyen TQ, Marder SR, Kippelen B. Solution-based electrical doping of semiconducting polymer films over a limited depth. NATURE MATERIALS 2017; 16:474-480. [PMID: 27918568 DOI: 10.1038/nmat4818] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
Solution-based electrical doping protocols may allow more versatility in the design of organic electronic devices; yet, controlling the diffusion of dopants in organic semiconductors and their stability has proven challenging. Here we present a solution-based approach for electrical p-doping of films of donor conjugated organic semiconductors and their blends with acceptors over a limited depth with a decay constant of 10-20 nm by post-process immersion into a polyoxometalate solution (phosphomolybdic acid, PMA) in nitromethane. PMA-doped films show increased electrical conductivity and work function, reduced solubility in the processing solvent, and improved photo-oxidative stability in air. This approach is applicable to a variety of organic semiconductors used in photovoltaics and field-effect transistors. PMA doping over a limited depth of bulk heterojunction polymeric films, in which amine-containing polymers were mixed in the solution used for film formation, enables single-layer organic photovoltaic devices, processed at room temperature, with power conversion efficiencies up to 5.9 ± 0.2% and stable performance on shelf-lifetime studies at 60 °C for at least 280 h.
Collapse
Affiliation(s)
- Vladimir A Kolesov
- Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Canek Fuentes-Hernandez
- Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Wen-Fang Chou
- Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Naoya Aizawa
- INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Felipe A Larrain
- Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Ming Wang
- Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA
| | - Alberto Perrotta
- Department of Applied Physics, Eindhoven University of Technology, Box 513, 5600 MB Eindhoven, Netherlands
| | - Sangmoo Choi
- Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Samuel Graham
- Center for Organic Photonics and Electronics (COPE), School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Guillermo C Bazan
- Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA
| | - Thuc-Quyen Nguyen
- Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA
| | - Seth R Marder
- Center for Organic Photonics and Electronics (COPE), School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Bernard Kippelen
- Center for Organic Photonics and Electronics (COPE), School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| |
Collapse
|
31
|
Streletskiy AV, Kellner ID, Nye LC, Drewello T, Hvelplund P, Boltalina OV. Formation of gas-phase metal fluorides in reactions of fluorinated fullerenes at activated metal surfaces. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2016.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
32
|
Fathollahi M, Ameri M, Mohajerani E, Mehrparvar E, Babaei M. Organic/Organic Heterointerface Engineering to Boost Carrier Injection in OLEDs. Sci Rep 2017; 7:42787. [PMID: 28218246 PMCID: PMC5316975 DOI: 10.1038/srep42787] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 01/17/2017] [Indexed: 12/03/2022] Open
Abstract
We investigate dynamic formation of nanosheet charge accumulations by heterointerface engineering in double injection layer (DIL) based organic light emitting diodes (OLEDs). Our experimental results show that the device performance is considerably improved for the DIL device as the result of heterointerface injection layer (HIIL) formation, in comparison to reference devices, namely, the current density is doubled and even quadrupled and the turn-on voltage is favorably halved, to 3.7 V, which is promising for simple small-molecule OLEDs. The simulation reveals the (i) formation of dynamic p-type doping (DPD) region which treats the quasi Fermi level at the organic/electrode interface, and (ii) formation of dynamic dipole layer (DDL) and the associated electric field at the organic/organic interface which accelerates the ejection of the carriers and their transference to the successive layer. HIIL formation proposes alternate scenarios for device design. For instance, no prerequisite for plasma treatment of transparent anode electrode, our freedom in varying the thicknesses of the organic layers between 10 nm and 60 nm for the first layer and between 6 nm and 24 nm for the second layer. The implications of the present work give insight into the dynamic phenomena in OLEDs and facilitates the development of their inexpensive fabrication for lighting applications.
Collapse
Affiliation(s)
- Mohammadreza Fathollahi
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| | - Mohsen Ameri
- Department of Physics, Bu-Ali Sina University, P.O. Box 65174, Hamedan, Iran
| | - Ezeddin Mohajerani
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| | - Ebrahim Mehrparvar
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| | - Mohammadrasoul Babaei
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113, Iran
| |
Collapse
|
33
|
Synthesis, characterization, and crystal structures of molybdenum complexes of unsymmetrical electron-poor dithiolene ligands. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.04.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|