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Wu Y, Salamat CZ, León Ruiz A, Simafranca AF, Akmanşen-Kalayci N, Wu EC, Doud E, Mehmedović Z, Lindemuth JR, Phan MD, Spokoyny AM, Schwartz BJ, Tolbert SH. Using Bulky Dodecaborane-Based Dopants to Produce Mobile Charge Carriers in Amorphous Semiconducting Polymers. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:5552-5562. [PMID: 38883433 PMCID: PMC11171275 DOI: 10.1021/acs.chemmater.4c00502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 06/18/2024]
Abstract
Conjugated polymers are a versatile class of electronic materials featured in a variety of next-generation electronic devices. The utility of such polymers is contingent in large part on their electrical conductivity, which depends both on the density of charge carriers (polarons) and on the carrier mobility. Carrier mobility, in turn, is largely controlled by the separation between the polarons and dopant counterions, as counterions can produce Coulombic traps. In previous work, we showed that large dopants based on dodecaborane (DDB) clusters were able to reduce Coulombic binding and thus increase carrier mobility in regioregular (RR) poly(3-hexylthiophene-2,5-diyl) (P3HT). Here, we use a DDB-based dopant to study the effects of polaron-counterion separation in chemically doped regiorandom (RRa) P3HT, which is highly amorphous. X-ray scattering shows that the DDB dopants, despite their large size, can partially order the RRa P3HT during doping and produce a doped polymer crystal structure similar to that of DDB-doped RR P3HT; Alternating Field (AC) Hall measurements also confirm a similar hole mobility. We also show that use of the large DDB dopants successfully reduces Coulombic binding of polarons and counterions in amorphous polymer regions, resulting in a 77% doping efficiency in RRa P3HT films. The DDB dopants are able to produce RRa P3HT films with a 4.92 S/cm conductivity, a value that is ∼200× higher than that achieved with 3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), the traditional dopant molecule. These results show that tailoring dopants to produce mobile carriers in both the amorphous and semicrystalline regions of conjugated polymers is an effective strategy for increasing achievable polymer conductivities, particularly in low-cost polymers with random regiochemistry. The results also emphasize the importance of dopant size and shape for producing Coulombically unbound, mobile polarons capable of electrical conduction in less-ordered materials.
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Affiliation(s)
- Yutong Wu
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Charlene Z Salamat
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Alex León Ruiz
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Alexander F Simafranca
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Nesibe Akmanşen-Kalayci
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Eric C Wu
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Evan Doud
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Zerina Mehmedović
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | | | - Minh D Phan
- Center for Neutron Science, Department of Chemical and Biochemical Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
| | - Sarah H Tolbert
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095-1569, United States
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095-1595, United States
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2
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Xiong M, Deng XY, Tian SY, Liu KK, Fang YH, Wang JR, Wang Y, Liu G, Chen J, Villalva DR, Baran D, Gu X, Lei T. Counterion docking: a general approach to reducing energetic disorder in doped polymeric semiconductors. Nat Commun 2024; 15:4972. [PMID: 38862491 PMCID: PMC11166965 DOI: 10.1038/s41467-024-49208-x] [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: 09/01/2023] [Accepted: 05/21/2024] [Indexed: 06/13/2024] Open
Abstract
Molecular doping plays an important role in controlling the carrier concentration of organic semiconductors. However, the introduction of dopant counterions often results in increased energetic disorder and traps due to the molecular packing disruption and Coulomb potential wells. To date, no general strategy has been proposed to reduce the counterion-induced structural and energetic disorder. Here, we demonstrate the critical role of non-covalent interactions (NCIs) between counterions and polymers. Employing a computer-aided approach, we identified the optimal counterions and discovered that NCIs determine their docking positions, which significantly affect the counterion-induced energetic disorder. With the optimal counterions, we successfully reduced the energetic disorder to levels even lower than that of the undoped polymer. As a result, we achieved a high n-doped electrical conductivity of over 200 S cm-1 and an eight-fold increase in the thermoelectric power factor. We found that the NCIs have substantial effects on doping efficiency, polymer backbone planarity, and Coulomb potential landscape. Our work not only provides a general strategy for identifying the most suitable counterions but also deepens our understanding of the counterion effects on doped polymeric semiconductors.
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Affiliation(s)
- Miao Xiong
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
- Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Xin-Yu Deng
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Shuang-Yan Tian
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Kai-Kai Liu
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Yu-Hui Fang
- Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Juan-Rong Wang
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Yunfei Wang
- School of Polymer Science and Engineering, Center for Optoelectronic Materials and Devices, The University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Guangchao Liu
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Jupeng Chen
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China
| | - Diego Rosas Villalva
- Materials Science and Engineering Program (MSE), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Derya Baran
- Materials Science and Engineering Program (MSE), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Xiaodan Gu
- School of Polymer Science and Engineering, Center for Optoelectronic Materials and Devices, The University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Ting Lei
- Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
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3
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Ready AD, Nelson YA, Torres Pomares DF, Spokoyny AM. Redox-Active Boron Clusters. Acc Chem Res 2024; 57:1310-1324. [PMID: 38619089 DOI: 10.1021/acs.accounts.4c00040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
ConspectusIn this Account, we discuss our group's research over the past decade on a class of functionalized boron clusters with tunable chemical and physical properties, with an emphasis on accessing and controlling their redox behavior. These clusters can be thought of as three-dimensional aromatic systems that have distinct redox behavior and photophysical properties compared to their two-dimensional organic counterparts. Specifically, our lab has studied the highly tunable, multielectron redox behavior of B12(OR)12 clusters and applied these molecules in various settings. We first discuss the spectroscopic and electrochemical characterization of B12(OR)12 clusters in various oxidation states, followed by their use as catholytes and/or anolytes in redox flow batteries and chemical dopants in conjugated polymers. Additionally, the high oxidizing potential and visible light-absorbing nature of fluoroaryl-functionalized B12(OR)12 clusters have been leveraged by our group to generate weakly coordinating, photoexcitable species that can promote photooxidation chemistry.We have further translated these solution-phase studies of B12(OR)12 clusters to the solid state by using the precursor [B12(OH)12]2- cluster as a robust building block for hybrid metal oxide materials. Specifically, we have shown that the boron cluster can act as a thermally stable cross-linking material, which enhances electron transport between metal oxide nanoparticles. We applied this structural motif to create TiO2- and WO3-containing materials that showed promising properties as photocatalysts and electroactive materials for supercapacitors. Building on this concept, we later discovered that B12(OCH3)12, the smallest of the B12(OR)12 family, could retain its redox behavior in the solid state, a previously unseen phenomenon. We successfully harnessed this unique behavior for solid-state energy storage by implementing this boron cluster as a cathode-active material in a Li-ion prototype cell device. Recently, our group has also explored how to tune the redox properties of clusters other than B12(OR)12 species by synthesizing a library of vertex-differentiated clusters containing both B-OR and B-halogen groups. Due to the additive qualities of different functional groups on the cluster, these species allow access to a region of electrochemical potentials previously inaccessible by fully substituted closo-dodecaborate alkoxy-based derivatives.Lastly, we discuss our research into smaller-sized redox-active polyhedral boranes (B6- and B10-based cluster cores). Interestingly, these clusters show significantly less redox stability and reversibility than their dodecaborate-based counterparts. While exploring the functionalization of closo-hexaborate to create fully substituted derivates (i.e., [B6R6Hfac]-), we observed unique oxidative decomposition pathways for this cluster system. Consequently, we leveraged this oxidative instability to generate useful alkyl boronate esters via selective chemical oxidation. We further explored a closo-decaborate cluster as a platform to access electrophilic [B10H13]+ species capable of directly borylating arene compounds with unique regioselectivity. Upon chemical oxidation of the arylated decaborate clusters, we successfully synthesized various aryl boronate esters, establishing the generality of the oxidative cluster deconstruction concept.Overall, our work shows that boron clusters are an appealing class of redox-active molecules, and this fundamental and understudied property can be leveraged for constructing novel materials with tunable physical and electrochemical properties, as well as producing unique chemical reagents for small molecule synthesis.
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Affiliation(s)
- Austin D Ready
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Yessica A Nelson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Daniel F Torres Pomares
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
- California NanoSystems Institute (CNSI), University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095, United States
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4
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Jia Y, Jiang Q, Gan H, Wang B, He X, Zhou J, Ma Z, Zhang J, Ma Y. Band-like transport in solution-processed perylene diimide dianion films with high Hall mobility. Natl Sci Rev 2024; 11:nwae087. [PMID: 38606386 PMCID: PMC11008685 DOI: 10.1093/nsr/nwae087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/27/2024] [Accepted: 03/06/2024] [Indexed: 04/13/2024] Open
Abstract
It is crucial to prepare high-mobility organic polycrystalline film through solution processing. However, the delocalized carrier transport of polycrystalline films in organic semiconductors has rarely been investigated through Hall-effect measurement. This study presents a strategy for building strong intermolecular interactions to fabricate solution-crystallized p-type perylene diimide (PDI) dianion films with a closer intermolecular π-π stacking distance of 3.25 Å. The highly delocalized carriers enable a competitive Hall mobility of 3 cm2 V-1 s-1, comparable to that of the reported high-mobility organic single crystals. The PDI dianion films exhibit a high electrical conductivity of 17 S cm-1 and typical band-like transport, as evidenced by the negative temperature linear coefficient of mobility proportional to T-3/2. This work demonstrates that, as the intermolecular π-π interactions become strong enough, they will display high mobility and conductivity, providing a new approach to developing high-mobility organic semiconductor materials.
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Affiliation(s)
- Yanhua Jia
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Qinglin Jiang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Hanlin Gan
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Bohan Wang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Xiandong He
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Jiadong Zhou
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Zetong Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Jiang Zhang
- Department of Physics, South China University of Technology, Guangzhou 510640, China
| | - Yuguang Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
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5
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Dagar M, Brennessel WW, Matson EM. Elucidation of Design Criteria for V-based Redox Mediators: Structure-Function Relationships that Dictate Rates of Heterogeneous Electron Transfer. Chemistry 2024:e202400764. [PMID: 38574277 DOI: 10.1002/chem.202400764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 03/30/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024]
Abstract
Redox mediators are attractive solutions for addressing the stringent kinetic stipulations required for efficient energy conversion processes. In this work, we compare the electrochemical properties of four vanadium complexes, namely [V(acac)3], [V6O7(OMe)12], [nBu4N]3[V6O13(TRISNO2)2], and [nBu4N]5[V18O46(NO3)] in non-aqueous solutions on glassy carbon electrodes. The goal of this study is to investigate the electron transfer kinetics and diffusivity of these compounds under identical experimental conditions to develop an understanding of structure-function relationships that dictate the physicochemical properties of vanadium oxide assemblies. Complex selection was dictated by two criteria - (1) nuclearity of the transition metal complexes (2) distribution of electron density in the native electronic configuration. Our analyses establish that electronic communication between metal centers significantly impacts charge transfer kinetics of these vanadium-based compounds.
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Affiliation(s)
- Mamta Dagar
- University of Rochester, Department of Chemistry, Rochester, NY 14627, USA
| | | | - Ellen M Matson
- University of Rochester, Department of Chemistry, Rochester, NY 14627, USA
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6
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Verma A, Jackson NE. Assessing molecular doping efficiency in organic semiconductors with reactive Monte Carlo. J Chem Phys 2024; 160:104106. [PMID: 38465678 DOI: 10.1063/5.0197816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/22/2024] [Indexed: 03/12/2024] Open
Abstract
The addition of molecular dopants into organic semiconductors (OSCs) is a ubiquitous augmentation strategy to enhance the electrical conductivity of OSCs. Although the importance of optimizing OSC-dopant interactions is well-recognized, chemically generalizable structure-function relationships are difficult to extract due to the sensitivity and dependence of doping efficiency on chemistry, processing conditions, and morphology. Computational modeling for an integrated OSC-dopant design is an attractive approach to systematically isolate fundamental relationships, but requires the challenging simultaneous treatment of molecular reactivity and morphology evolution. We present the first computational study to couple molecular reactivity with morphology evolution in a molecularly doped OSC. Reactive Monte Carlo is employed to examine the evolution of OSC-dopant morphologies and doping efficiency with respect to dielectric, the thermodynamic driving for the doping reaction, and dopant aggregation. We observe that for well-mixed systems with experimentally relevant dielectric constants, doping efficiency is near unity with a very weak dependence on the ionization potential and electron affinity of OSC and dopant, respectively. At experimental dielectric constants, reaction-induced aggregation is observed, corresponding to the well-known insolubility of solution-doped materials. Simulations are qualitatively consistent with a number of experimental studies showing a decrease of doping efficiency with increasing dopant concentration. Finally, we observe that the aggregation of dopants lowers doping efficiency and thus presents a rational design strategy for maximizing doping efficiency in molecularly doped OSCs. This work represents an important first step toward the systematic integration of molecular reactivity and morphology evolution into the characterization of multi-scale structure-function relationships in molecularly doped OSCs.
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Affiliation(s)
- Archana Verma
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Nicholas E Jackson
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
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7
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Zhang P, Zhu B, Du P, Travas-Sejdic J. Electrochemical and Electrical Biosensors for Wearable and Implantable Electronics Based on Conducting Polymers and Carbon-Based Materials. Chem Rev 2024; 124:722-767. [PMID: 38157565 DOI: 10.1021/acs.chemrev.3c00392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Bioelectronic devices are designed to translate biological information into electrical signals and vice versa, thereby bridging the gap between the living biological world and electronic systems. Among different types of bioelectronics devices, wearable and implantable biosensors are particularly important as they offer access to the physiological and biochemical activities of tissues and organs, which is significant in diagnosing and researching various medical conditions. Organic conducting and semiconducting materials, including conducting polymers (CPs) and graphene and carbon nanotubes (CNTs), are some of the most promising candidates for wearable and implantable biosensors. Their unique electrical, electrochemical, and mechanical properties bring new possibilities to bioelectronics that could not be realized by utilizing metals- or silicon-based analogues. The use of organic- and carbon-based conductors in the development of wearable and implantable biosensors has emerged as a rapidly growing research field, with remarkable progress being made in recent years. The use of such materials addresses the issue of mismatched properties between biological tissues and electronic devices, as well as the improvement in the accuracy and fidelity of the transferred information. In this review, we highlight the most recent advances in this field and provide insights into organic and carbon-based (semi)conducting materials' properties and relate these to their applications in wearable/implantable biosensors. We also provide a perspective on the promising potential and exciting future developments of wearable/implantable biosensors.
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Affiliation(s)
- Peikai Zhang
- Centre for Innovative Materials for Health, School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand
- Auckland Bioengineering Institute, The University of Auckland, Auckland 1010, New Zealand
| | - Bicheng Zhu
- Centre for Innovative Materials for Health, School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, The University of Auckland, Auckland 1010, New Zealand
| | - Jadranka Travas-Sejdic
- Centre for Innovative Materials for Health, School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand
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8
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Dyksik M, Beret D, Baranowski M, Duim H, Moyano S, Posmyk K, Mlayah A, Adjokatse S, Maude DK, Loi MA, Puech P, Plochocka P. Polaron Vibronic Progression Shapes the Optical Response of 2D Perovskites. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305182. [PMID: 38072637 PMCID: PMC10870061 DOI: 10.1002/advs.202305182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/23/2023] [Indexed: 02/17/2024]
Abstract
The optical response of 2D layered perovskites is composed of multiple equally-spaced spectral features, often interpreted as phonon replicas, separated by an energy Δ ≃ 12 - 40 meV, depending upon the compound. Here the authors show that the characteristic energy spacing, seen in both absorption and emission, is correlated with a substantial scattering response above ≃ 200 cm-1 (≃ 25 meV) observed in resonant Raman. This peculiar high-frequency signal, which dominates both Stokes and anti-Stokes regions of the scattering spectra, possesses the characteristic spectral fingerprints of polarons. Notably, its spectral position is shifted away from the Rayleigh line, with a tail on the high energy side. The internal structure of the polaron consists of a series of equidistant signals separated by 25-32 cm-1 (3-4 meV), depending upon the compound, forming a polaron vibronic progression. The observed progression is characterized by a large Huang-Rhys factor (S > 6) for all of the 2D layered perovskites investigated here, indicative of a strong charge carrier - lattice coupling. The polaron binding energy spans a range ≃ 20-35 meV, which is corroborated by the temperature-dependent Raman scattering data. The investigation provides a complete understanding of the optical response of 2D layered perovskites via the direct observation of polaron vibronic progression. The understanding of polaronic effects in perovskites is essential, as it directly influences the suitability of these materials for future opto-electronic applications.
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Affiliation(s)
- Mateusz Dyksik
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
| | - Dorian Beret
- CEMES‐UPR8011CNRSUniversity of Toulouse29 rue Jeanne MarvigToulouse31500France
| | - Michal Baranowski
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
| | - Herman Duim
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Sébastien Moyano
- CEMES‐UPR8011CNRSUniversity of Toulouse29 rue Jeanne MarvigToulouse31500France
| | - Katarzyna Posmyk
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
- Laboratoire National des Champs Magnétiques IntensesEMFL, CNRS UPR 3228University Toulouse, University Toulouse 3, INSA‐T, University Grenoble AlpesGrenoble and ToulouseFrance
| | - Adnen Mlayah
- LAASUniversity of ToulouseCNRS, UPS, 7 Avenue du Colonel RocheToulouse31031France
| | - Sampson Adjokatse
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Duncan K. Maude
- Laboratoire National des Champs Magnétiques IntensesEMFL, CNRS UPR 3228University Toulouse, University Toulouse 3, INSA‐T, University Grenoble AlpesGrenoble and ToulouseFrance
| | - Maria Antonietta Loi
- Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Pascal Puech
- CEMES‐UPR8011CNRSUniversity of Toulouse29 rue Jeanne MarvigToulouse31500France
| | - Paulina Plochocka
- Department of Experimental PhysicsFaculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclaw50370Poland
- Laboratoire National des Champs Magnétiques IntensesEMFL, CNRS UPR 3228University Toulouse, University Toulouse 3, INSA‐T, University Grenoble AlpesGrenoble and ToulouseFrance
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9
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Hermosilla-Palacios MA, Martinez M, Doud EA, Hertel T, Spokoyny AM, Cambré S, Wenseleers W, Kim YH, Ferguson AJ, Blackburn JL. Carrier density and delocalization signatures in doped carbon nanotubes from quantitative magnetic resonance. NANOSCALE HORIZONS 2024; 9:278-284. [PMID: 38044846 DOI: 10.1039/d3nh00480e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
High-performance semiconductor materials and devices are needed to supply the growing energy and computing demand. Organic semiconductors (OSCs) are attractive options for opto-electronic devices, due to their low cost, extensive tunability, easy fabrication, and flexibility. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been extensively studied due to their high carrier mobility, stability and opto-electronic tunability. Although molecular charge transfer doping affords widely tunable carrier density and conductivity in s-SWCNTs (and OSCs in general), a pervasive challenge for such systems is reliable measurement of charge carrier density and mobility. In this work we demonstrate a direct quantification of charge carrier density, and by extension carrier mobility, in chemically doped s-SWCNTs by a nuclear magnetic resonance approach. The experimental results are verified by a phase-space filling doping model, and we suggest this approach should be broadly applicable for OSCs. Our results show that hole mobility in doped s-SWCNT networks increases with increasing charge carrier density, a finding that is contrary to that expected for mobility limited by ionized impurity scattering. We discuss the implications of this important finding for additional tunability and applicability of s-SWCNT and OSC devices.
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Affiliation(s)
| | - Marissa Martinez
- National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
| | - Evan A Doud
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
| | - Tobias Hertel
- Institute of Physical and Theoretical Chemistry, Julius-Maximilian, University Würzburg, 97074, Würzburg, Germany
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
| | - Sofie Cambré
- Department of Physics, University of Antwerp, Antwerp 2610, Belgium
| | - Wim Wenseleers
- Department of Physics, University of Antwerp, Antwerp 2610, Belgium
| | - Yong-Hyun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
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10
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Fidanovski K, Gu M, Travaglini L, Lauto A, Mawad D. Self-Doping and Self-Acid-Doping of Conjugated Polymer Bioelectronics: The Case for Accuracy in Nomenclature. Adv Healthc Mater 2023:e2302354. [PMID: 37883783 DOI: 10.1002/adhm.202302354] [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: 07/24/2023] [Revised: 10/16/2023] [Indexed: 10/28/2023]
Abstract
Conjugated polymers are enabling the development of flexible bioelectronics, largely driven by their organic nature which facilitates modification and tuning to suit a variety of applications. As organic semiconductors, conjugated polymers require a dopant to exhibit electrical conductivity, which in physiological conditions can result in dopant loss and thereby deterioration in electronic properties. To overcome this challenge, "self-doped" and self-acid-doped conjugated polymers having ionized pendant groups covalently bound to their backbone are being developed. The ionized group in a "self-doped" polymer behaves as the counterion that maintains electroneutrality, while an external dopant is required to induce charge transfer. The ionized group in a self-acid-doped polymer induces charge transfer and behaves as the counterion balancing the charges. Despite their doping processes being different, the two terms, self-doped and self-acid-doped, are often used interchangeably in the literature. Here, the differences are highlighted in the doping mechanisms of self-doped and self-acid-doped polymers, and it is proposed that the term "self-doped" should be replaced by "self-compensated," while reserving the term self-acid-doped for polymers that are intrinsically doped without the need of an external dopant. This is followed by a summary of examples of self-acid-doping in bioelectronics, highlighting their stability in the conductive state under physiological conditions.
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Affiliation(s)
- Kristina Fidanovski
- School of Materials Science and Engineering, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Modi Gu
- School of Materials Science and Engineering, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Lorenzo Travaglini
- School of Materials Science and Engineering, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Antonio Lauto
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, 2751, Australia
| | - Damia Mawad
- School of Materials Science and Engineering, UNSW Sydney, Sydney, New South Wales, 2052, Australia
- Australian Centre for NanoMedicine, UNSW Sydney, Sydney, New South Wales, 2052, Australia
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11
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Wu EC, Schwartz BJ. Does the Traditional Band Picture Describe the Electronic Structure of Doped Conjugated Polymers? TD-DFT and Natural Transition Orbital Study of Doped P3HT. J Chem Theory Comput 2023; 19:6761-6769. [PMID: 37769199 DOI: 10.1021/acs.jctc.3c00743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Polarons and bipolarons are created when one or two electrons are removed from the π-system of a p-type conjugated polymer, respectively. In the traditional band picture, the creation of a polaron causes two electronic energy levels to move into the band gap. The removal of a second electron to form a bipolaron causes the two intragap states to move further into the gap. Several groups, however, who looked at the energies of the Kohn-Sham orbitals from DFT calculations, have recently argued that the traditional band picture is incorrect for explaining the spectroscopy of doped conjugated polymers. Instead, the DFT calculations suggest that polaron creation causes only one unoccupied state to move into the band gap near the valence band edge while half-filled state in the valence band and the conduction band bend downward in energy. To understand the discrepancy, we performed TD-DFT calculations of polarons and bipolarons on poly(3-hexylthiophene) (P3HT). Not only do the TD-DFT-calculated absorption spectra match the experimental absorption spectra, but an analysis using natural transitional orbitals (NTOs), which provides an approximate one-electron picture from the many-electron TD-DFT results, supports the traditional band picture. Our TD-DFT/NTO analysis indicates that the traditional band picture also works for bipolarons, a system for which DFT calculations were unable to determine the electronic structure.
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Affiliation(s)
- Eric C Wu
- Department of Chemistry and Biochemistry University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry University of California, Los Angeles, Los Angeles, California 90095-1569, United States
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12
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Mansour A, Warren R, Lungwitz D, Forster M, Scherf U, Opitz A, Malischewski M, Koch N. Coordination of Tetracyanoquinodimethane-Derivatives with Tris(pentafluorophenyl)borane Provides Stronger p-Dopants with Enhanced Stability. ACS APPLIED MATERIALS & INTERFACES 2023; 15:46148-46156. [PMID: 37730205 PMCID: PMC10561139 DOI: 10.1021/acsami.3c10373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 08/18/2023] [Indexed: 09/22/2023]
Abstract
Strong molecular dopants for organic semiconductors that are stable against diffusion are in demand, enhancing the performance of organic optoelectronic devices. The conventionally used p-dopants based on 7,7,8,8-tetracyanoquinodimethane (TCNQ) and its derivatives "FxTCN(N)Q", such as 2,3,4,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (F6TCNNQ), feature limited oxidation strength, especially for modern polymer semiconductors with high ionization energy (IE). These small molecular dopants also exhibit pronounced diffusion in the polymer hosts. Here, we demonstrate a facile approach to increase the oxidation strength of FxTCN(N)Q by coordination with four tris(pentafluorophenyl)borane (BCF) molecules using a single-step solution mixing process, resulting in bulky dopant complexes "FxTCN(N)Q-4(BCF)". Using a series of polymer semiconductors with IE up to 5.9 eV, we show by optical absorption spectroscopy of solutions and thin films that the efficiency of doping using FxTCN(N)Q-4(BCF) is significantly higher compared to that using FxTCN(N)Q or BCF alone. Electrical transport measurements with the prototypical poly(3-hexylthiophene-2,5-diyl) (P3HT) confirm the higher doping efficiency of F4TCNQ-4(BCF) compared to F4TCNQ. Additionally, the bulkier structure of F4TCNQ-4(BCF) is shown to result in higher stability against drift in P3HT under an applied electric field as compared to F4TCNQ. The simple approach of solution-mixing of readily accessible molecules thus offers access to enhanced molecular p-dopants for the community.
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Affiliation(s)
- Ahmed
E. Mansour
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Ross Warren
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Dominique Lungwitz
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Michael Forster
- Department
of Chemistry and Wuppertal Center for Smart Materials and Systems
(CM@S), Bergische Universität Wuppertal, 42097 Wuppertal, Germany
| | - Ullrich Scherf
- Department
of Chemistry and Wuppertal Center for Smart Materials and Systems
(CM@S), Bergische Universität Wuppertal, 42097 Wuppertal, Germany
| | - Andreas Opitz
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Moritz Malischewski
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, 14195 Berlin, Germany
| | - Norbert Koch
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
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13
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Hyun Suh E, Beom Kim S, Jung J, Jang J. Extremely Electron-Withdrawing Lewis-Paired CN Groups for Organic p-Dopants. Angew Chem Int Ed Engl 2023; 62:e202304245. [PMID: 37271729 DOI: 10.1002/anie.202304245] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/06/2023]
Abstract
P-type chemical doping (p-doping) is a key technique to modulate the optical, electrical, and electronic properties of organic semiconductors. However, typical functional groups in organic p-dopants have insufficient electron-withdrawing strength, and the inevitable diffusion of dopants in host matrices degrades doping stabilities. Herein, we utilize extremely electron-withdrawing Lewis-paired CN groups as a new class of building blocks for designing unprecedentedly strong organic p-dopants with excellent doping stability. Various Lewis acids are paired with CN-functionalized conjugated molecules in the solution state, which strengthens the electron-withdrawing properties of CN groups almost twofold. The large dopants afford outstanding doping stability against continuous heating and long-term atmospheric exposure, which is promising for practical applications in devices. Given the broad applicability of this simple combinatorial approach, it may impact many fields of (opto)electronics.
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Affiliation(s)
- Eui Hyun Suh
- Department of Energy Engineering, Hanyang University, 04763, Seoul, Republic of Korea
| | - Sang Beom Kim
- Department of Energy Engineering, Hanyang University, 04763, Seoul, Republic of Korea
| | - Jaemin Jung
- Department of Energy Engineering, Hanyang University, 04763, Seoul, Republic of Korea
| | - Jaeyoung Jang
- Department of Energy Engineering, Hanyang University, 04763, Seoul, Republic of Korea
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14
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Le VN, Bombile JH, Rupasinghe GS, Baustert KN, Li R, Maria IP, Shahi M, Alarcon Espejo P, McCulloch I, Graham KR, Risko C, Paterson AF. New Chemical Dopant and Counterion Mechanism for Organic Electrochemical Transistors and Organic Mixed Ionic-Electronic Conductors. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207694. [PMID: 37466175 PMCID: PMC10520668 DOI: 10.1002/advs.202207694] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/07/2023] [Indexed: 07/20/2023]
Abstract
Organic mixed ionic-electronic conductors (OMIECs) have varied performance requirements across a diverse application space. Chemically doping the OMIEC can be a simple, low-cost approach for adapting performance metrics. However, complex challenges, such as identifying new dopant materials and elucidating design rules, inhibit its realization. Here, these challenges are approached by introducing a new n-dopant, tetrabutylammonium hydroxide (TBA-OH), and identifying a new design consideration underpinning its success. TBA-OH behaves as both a chemical n-dopant and morphology additive in donor acceptor co-polymer naphthodithiophene diimide-based polymer, which serves as an electron transporting material in organic electrochemical transistors (OECTs). The combined effects enhance OECT transconductance, charge carrier mobility, and volumetric capacitance, representative of the key metrics underpinning all OMIEC applications. Additionally, when the TBA+ counterion adopts an "edge-on" location relative to the polymer backbone, Coulombic interaction between the counterion and polaron is reduced, and polaron delocalization increases. This is the first time such mechanisms are identified in doped-OECTs and doped-OMIECs. The work herein therefore takes the first steps toward developing the design guidelines needed to realize chemical doping as a generic strategy for tailoring performance metrics in OECTs and OMIECs.
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Affiliation(s)
- Vianna N. Le
- Department of Chemical and Materials EngineeringDepartment of Electrical EngineeringCentre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
| | - Joel H. Bombile
- Department of Chemistryand Centre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
| | - Gehan S. Rupasinghe
- Department of Chemical and Materials EngineeringDepartment of Electrical EngineeringCentre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
| | - Kyle N. Baustert
- Department of ChemistryUniversity of KentuckyLexingtonKY40506USA
| | | | - Iuliana P. Maria
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUK
| | - Maryam Shahi
- Department of Chemical and Materials EngineeringDepartment of Electrical EngineeringCentre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
| | - Paula Alarcon Espejo
- Department of Chemical and Materials EngineeringDepartment of Electrical EngineeringCentre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
| | - Iain McCulloch
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUK
- King Abdullah University of Science and TechnologyKAUST Solar CentreThuwal23955‐6900Saudi Arabia
| | | | - Chad Risko
- Department of Chemistryand Centre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
| | - Alexandra F. Paterson
- Department of Chemical and Materials EngineeringDepartment of Electrical EngineeringCentre for Applied Energy ResearchUniversity of KentuckyLexingtonKY40506USA
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15
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Wang D, Yu H, Shi W, Xu C. Chemical Doping of Organic and Coordination Polymers for Thermoelectric and Spintronic Applications: A Theoretical Understanding. Acc Chem Res 2023; 56:2127-2138. [PMID: 37432731 DOI: 10.1021/acs.accounts.3c00091] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
ConspectusThe controlled doping of organic semiconductors (OSCs) is crucial not only for improving the performance of electronic and optoelectronic devices but also for enabling efficient thermoelectric conversion and spintronic applications. The mechanism of doping for OSCs is fundamentally different from that of their inorganic counterparts. In particular, the interplay between dopants and host materials is complicated considering the low dielectric constant, strong lattice-charge interaction, and flexible nature of materials. Recent experimental breakthroughs in the molecular design of dopants and the precise doping with high spatial resolution call for more profound understandings as to how the dopant interacts with the charge introduced to OSCs and how the admixture of dopants alters the electronic properties of host materials before one can exploit controllable doping to realize desired functionalities.By employing state-of-the-art computational tools, we revealed the effects of doping in representative and emerging organic and coordination polymers aiming toward thermoelectric and spintronic applications. We showed that dopants and hosts should be taken as an integrated system, and the type of charge-transfer interaction between them is the key for spin polarization. First, we found doping-induced modifications to the electronic band in a potassium-doped coordination polymer, an n-type thermoelectric material. The charge localization due to the Coulomb interaction between the completely ionized dopant and the injected charge on the polymer backbone and also the polaron band formation at low doping levels are responsible for the nonmonotonic temperature dependence of the conductivity and Seebeck coefficient observed in recent experiments. The mechanistic insights gained from these results have provided important guidelines on how to control the doping level and working temperature to achieve a high thermoelectric conversion efficiency. Next, we demonstrated that the ionized dopants scatter charge carriers via screened Coulomb interactions, and it may become a dominant scattering mechanism in doped polymers. After incorporating the ionized dopant scattering mechanism in PEDOT:Tos, a p-type thermoelectric polymer, we were able to reproduce the measured Seebeck coefficient-electrical conductivity relationship spanning a wide range of doping levels, highlighting the importance of ionized dopant scattering in charge transport.In the two cases described above, charge injection is enabled by integral charge transfer between the dopant and host polymers. In a third example, we showed that a novel type of stacked two-dimensional polymer, conjugated covalent organic frameworks (COFs) with closed-shell electronic structures, can be spin polarized by iodine doping via fractional charge transfer even at high doping levels. We then manifested that magnetization can be attained in nonmagnetic materials lacking metal d electrons and further designed two new COFs with tunable spintronic structure and magnetic interactions after the iodine doping. These findings have suggested a practical route to enable spin polarization in nonradical materials by chemical doping via orbital hybridization, which holds great promise for flexible spintronic applications.
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Affiliation(s)
- Dong Wang
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing 100084, P. R. China
- MOE Key Laboratory of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Hongde Yu
- Faculty of Chemistry and Food Chemistry, TU Dresden, 01069 Dresden, Germany
| | - Wen Shi
- School of Chemistry, Sun Yat-sen University, Guangzhou 510006, China
| | - Chunlin Xu
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing 100084, P. R. China
- MOE Key Laboratory of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
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16
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Yuan D, Liu W, Zhu X. Efficient and air-stable n-type doping in organic semiconductors. Chem Soc Rev 2023. [PMID: 37183967 DOI: 10.1039/d2cs01027e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Chemical doping of organic semiconductors (OSCs) enables feasible tuning of carrier concentration, charge mobility, and energy levels, which is critical for the applications of OSCs in organic electronic devices. However, in comparison with p-type doping, n-type doping has lagged far behind. The achievement of efficient and air-stable n-type doping in OSCs would help to significantly improve electron transport and device performance, and endow new functionalities, which are, therefore, gaining increasing attention currently. In this review, the issue of doping efficiency and doping air stability in n-type doped OSCs was carefully addressed. We first clarified the main factors that influenced chemical doping efficiency in n-type OSCs and then explain the origin of instability in n-type doped films under ambient conditions. Doping microstructure, charge transfer, and dissociation efficiency were found to determine the overall doping efficiency, which could be precisely tuned by molecular design and post treatments. To further enhance the air stability of n-doped OSCs, design strategies such as tuning the lowest unoccupied molecular orbital (LUMO) energy level, charge delocalization, intermolecular stacking, in situ n-doping, and self-encapsulations are discussed. Moreover, the applications of n-type doping in advanced organic electronics, such as solar cells, light-emitting diodes, field-effect transistors, and thermoelectrics are being introduced. Finally, an outlook is provided on novel doping ways and material systems that are aimed at stable and efficient n-type doped OSCs.
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Affiliation(s)
- Dafei Yuan
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Wuyue Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Xiaozhang Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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17
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Barrett BJ, Katz HE, Bragg AE. Permittivity Threshold and Thermodynamics of Integer Charge-Transfer Complexation for an Organic Donor-Acceptor Pair. J Phys Chem B 2023; 127:2792-2800. [PMID: 36926897 DOI: 10.1021/acs.jpcb.3c00218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Molecular charge doping involves the formation of donor-acceptor charge-transfer complexes (CTCs) through integer or partial electron transfer; understanding how local chemical environment impacts complexation is important for controlling the properties of organic materials. We present steady-state and temperature-dependent spectroscopic investigations of the p-dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) complexed with the electron donor and hole transport material N,N'-diphenyl-N,N'-di-p-tolylbenzene-1,4-diamine (MPDA). Equilibrium formation constants (KCT) were determined for donor-acceptor pairs dissolved in a series of solvents covering a range of values of permittivity. A threshold for highly favorable complex formation was observed to occur at ϵ ∼ 8-9, with large (>104) and small (<103) values of KCT obtained in solvents of higher and lower permittivity, respectively, but with chloroform (ϵ = 4.81) exhibiting an anomalously high formation constant. Temperature-dependent formation constants were determined in order to evaluate the thermodynamics of complex formation. In 1,2-dichloroethane (ϵ = 10.36) and chlorobenzene (ϵ = 5.62), complex formation is both enthalpically and entropically favorable, with higher enthalpic and entropic stabilization in the solvent with higher permittivity. Complexation in chloroform is exothermic and entropically disfavored, indicating that specific, inner-shell solvent-solute interactions stabilize the charge-separated complex and result in a net increase in local solution structure. Our results provide insight into how modification to the chemical environment may be utilized to support stable integer charge transfer for molecular doping applications and requiring only modest changes in local permittivity.
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Affiliation(s)
- Brandon J Barrett
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
| | - Howard E Katz
- Department of Material Science & Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
| | - Arthur E Bragg
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
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18
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Ghosh R, Paesani F. Connecting the dots for fundamental understanding of structure-photophysics-property relationships of COFs, MOFs, and perovskites using a Multiparticle Holstein Formalism. Chem Sci 2023; 14:1040-1064. [PMID: 36756323 PMCID: PMC9891456 DOI: 10.1039/d2sc03793a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/09/2022] [Indexed: 11/17/2022] Open
Abstract
Photoactive organic and hybrid organic-inorganic materials such as conjugated polymers, covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and layered perovskites, display intriguing photophysical signatures upon interaction with light. Elucidating structure-photophysics-property relationships across a broad range of functional materials is nontrivial and requires our fundamental understanding of the intricate interplay among excitons (electron-hole pair), polarons (charges), bipolarons, phonons (vibrations), inter-layer stacking interactions, and different forms of structural and conformational defects. In parallel with electronic structure modeling and data-driven science that are actively pursued to successfully accelerate materials discovery, an accurate, computationally inexpensive, and physically-motivated theoretical model, which consistently makes quantitative connections with conceptually complicated experimental observations, is equally important. Within this context, the first part of this perspective highlights a unified theoretical framework in which the electronic coupling as well as the local coupling between the electronic and nuclear degrees of freedom can be efficiently described for a broad range of quasiparticles with similarly structured Holstein-style vibronic Hamiltonians. The second part of this perspective discusses excitonic and polaronic photophysical signatures in polymers, COFs, MOFs, and perovskites, and attempts to bridge the gap between different research fields using a common theoretical construct - the Multiparticle Holstein Formalism. We envision that the synergistic integration of state-of-the-art computational approaches with the Multiparticle Holstein Formalism will help identify and establish new, transformative design strategies that will guide the synthesis and characterization of next-generation energy materials optimized for a broad range of optoelectronic, spintronic, and photonic applications.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093 USA
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093 USA
- San Diego Supercomputer Center, University of California La Jolla San Diego California 92093 USA
- Materials Science and Engineering, University of California La Jolla San Diego California 92093 USA
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19
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Kim SH, Yook H, Sung W, Choi J, Lim H, Chung S, Han JW, Cho K. Extremely Suppressed Energetic Disorder in a Chemically Doped Conjugated Polymer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207320. [PMID: 36271732 DOI: 10.1002/adma.202207320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Chemical doping can be used to tune the optoelectronic properties of conjugated polymers (CPs), extending their applications as conducting materials. Unfortunately, chemically doped CP films containing excess dopants exhibit an increase in energetic disorder upon structural alteration, and Coulomb interactions between charge carriers and dopants also affect such disorder. The increase in energetic disorder leads to a broadening of the density of states, which consequently impedes efficient charge transport in chemically doped CPs. However, the molecular origins that are inherently resistant to such incidental increase of energetic disorder in chemically doped CPs have not been sufficiently explored. Here, it is discovered that energetic disorder in chemically doped CPs can be suppressed to a level close to the theoretical limit. Indacenodithiophene-co-benzothiadiazole (IDTBT) doped with triethyloxonium hexachloroantimonate (OA) exhibits disorder-free charge-transport characteristics and band-like transport behavior with astonishing carrier mobility as a result of reinforced 1D intramolecular transport. Molecular structure of IDTBT provides a capability to lower the energetic disorder that generally arises from the inclusion of heterogeneous dopants. The results suggest the possibilities of implementing disorder-free CPs that exhibit excellent charge transport characteristics in the chemically doped state and satisfy a prerequisite for their availability in the industry.
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Affiliation(s)
- Seong Hyeon Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Hyunwoo Yook
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Woong Sung
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Jinhyeok Choi
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Hyungsub Lim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Sein Chung
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Jeong Woo Han
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Kilwon Cho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
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20
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Borrmann F, Tsuda T, Guskova O, Kiriy N, Hoffmann C, Neusser D, Ludwigs S, Lappan U, Simon F, Geisler M, Debnath B, Krupskaya Y, Al‐Hussein M, Kiriy A. Charge-Compensated N-Doped π-Conjugated Polymers: Toward both Thermodynamic Stability of N-Doped States in Water and High Electron Conductivity. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203530. [PMID: 36065004 PMCID: PMC9631074 DOI: 10.1002/advs.202203530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/27/2022] [Indexed: 05/28/2023]
Abstract
The understanding and applications of electron-conducting π-conjugated polymers with naphtalene diimide (NDI) blocks show remarkable progress in recent years. Such polymers demonstrate a facilitated n-doping due to the strong electron deficiency of the main polymer chain and the presence of the positively charged side groups stabilizing a negative charge of the n-doped backbone. Here, the n-type conducting NDI polymer with enhanced stability of its n-doped states for prospective "in-water" applications is developed. A combined experimental-theoretical approach is used to identify critical features and parameters that control the doping and electron transport process. The facilitated polymer reduction ability and the thermodynamic stability in water are confirmed by electrochemical measurements and doping studies. This material also demonstrates a high conductivity of 10-2 S cm-1 under ambient conditions and 10-1 S cm-1 in vacuum. The modeling explains the stabilizing effects for various dopants. The simulations show a significant doping-induced "collapse" of the positively charged side chains on the core bearing a partial negative charge. This explains a decrease in the lamellar spacing observed in experiments. This study fundamentally enables a novel pathway for achieving both thermodynamic stability of the n-doped states in water and the high electron conductivity of polymers.
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Affiliation(s)
- Fabian Borrmann
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - Takuya Tsuda
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - Olga Guskova
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
- Dresden Center for Computational Materials Science (DCMS)TU Dresden01062DresdenGermany
| | - Nataliya Kiriy
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - Cedric Hoffmann
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - David Neusser
- IPOC‐Functional PolymersInstitute of Polymer Chemistry & Center for Integrated Quantum Science and Technology (IQST)University of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Sabine Ludwigs
- IPOC‐Functional PolymersInstitute of Polymer Chemistry & Center for Integrated Quantum Science and Technology (IQST)University of StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Uwe Lappan
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - Frank Simon
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - Martin Geisler
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
| | - Bipasha Debnath
- Leibniz‐Institut für Festkörper‐ und Werkstoffforschung DresdenHelmholtzstraße 2001069DresdenGermany
| | - Yulia Krupskaya
- Leibniz‐Institut für Festkörper‐ und Werkstoffforschung DresdenHelmholtzstraße 2001069DresdenGermany
| | - Mahmoud Al‐Hussein
- Physics Department and Hamdi Mango Center for Scientific ResearchThe University of JordanAmman11942Jordan
| | - Anton Kiriy
- Leibniz‐Institut für Polymerforschung Dresden e.VHohe Straße 601069DresdenGermany
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21
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Wu ECK, Salamat CZ, Tolbert SH, Schwartz BJ. Molecular Dynamics Study of the Thermodynamics of Integer Charge Transfer vs Charge-Transfer Complex Formation in Doped Conjugated Polymers. ACS APPLIED MATERIALS & INTERFACES 2022; 14:26988-27001. [PMID: 35657331 DOI: 10.1021/acsami.2c06449] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Molecular dopants such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) can interact with conjugated polymers such as poly(3-hexylthiophene-2,5-diyl) (P3HT) in two different ways: they can undergo integer charge transfer (ICT) or they can form a partial-charge-transfer complex (CTC). Both are seen experimentally, but the CTC has been challenging to characterize, making it difficult to answer questions such as the following. Which polymorph is more stable? Do they have similar barriers for formation? Is there a thermodynamic route to convert one to the other? Here, we study the structure and the thermodynamics of bulk F4TCNQ-doped P3HT with all-atom molecular dynamics simulations, using thermodynamic integration to calculate the relative free energies. We find that the ICT and CTC polymorphs have similar thermodynamic stabilities. The barrier to create the ICT polymorph, however, is lower than that to make the CTC polymorph, because the ICT polymorph has a small critical nucleus, but the critical nucleus for the CTC polymorph is larger than what we can simulate. Moreover, simulated thermal annealing shows that the activation barrier for converting the CTC polymorph to the ICT polymorph is relatively modest. Overall, the simulations explain both the observed structures and the thermodynamics of F4TCNQ-doped P3HT and offer guidelines for targeting the production of a desired polymorph for different applications.
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Affiliation(s)
- Eric Chih-Kuan Wu
- Department of Chemistry and Biochemistry University of California, Los Angeles Los Angeles, California 90095-1569, United States
| | - Charlene Z Salamat
- Department of Chemistry and Biochemistry University of California, Los Angeles Los Angeles, California 90095-1569, United States
| | - Sarah H Tolbert
- Departments of Chemistry and Biochemistry and Materials Science and Engineering University of California, Los Angeles Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry University of California, Los Angeles Los Angeles, California 90095-1569, United States
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22
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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: 27] [Impact Index Per Article: 13.5] [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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23
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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: 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.
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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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24
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Ghosh R, Paesani F. Topology-Mediated Enhanced Polaron Coherence in Covalent Organic Frameworks. J Phys Chem Lett 2021; 12:9442-9448. [PMID: 34554754 DOI: 10.1021/acs.jpclett.1c02454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We employ the Holstein model for polarons to investigate the relationship among defects, topology, Coulomb trapping, and polaron delocalization in covalent organic frameworks (COFs). We find that intrasheet topological connectivity and π-column density can override disorder-induced deep traps and significantly enhance polaron migration by several orders of magnitude in good agreement with recent experimental observations. The combination of percolation networks and micropores makes trigonal COFs ideally suited for charge transport followed by kagome/tetragonal and hexagonal structures. By comparing the polaron spectral signatures and coherence numbers of large three-dimensional frameworks having a maximum of 180 coupled chromophores, we show that controlling nanoscale defects and the location of the counteranion is critical for the design of new COF-based materials yielding higher mobilities. Our analysis establishes design strategies for enhanced conductivity in COFs that can be readily generalized to other classes of conductive materials such as metal-organic frameworks and perovskites.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry and Biochemistry, ‡Materials Science and Engineering, and §San Diego Supercomputer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, ‡Materials Science and Engineering, and §San Diego Supercomputer Center, University of California, San Diego, La Jolla, California 92093, United States
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25
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Li B, Zhang X, Stauber JM, Miller TF, Spokoyny AM. Electronic Structure of Superoxidized Radical Cationic Dodecaborate-Based Clusters. J Phys Chem A 2021; 125:6141-6150. [PMID: 34240867 DOI: 10.1021/acs.jpca.1c03927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The expanding field of boron clusters has attracted continuous theoretical efforts to understand their diverse structures and unique bonding. We recently discovered a new reversible redox event of B12(O-3-methylbutyl)12 in which the superoxidized radical cationic form [B12(O-3-methylbutyl)12]•+ was identified and isolated for the first time. Herein, comprehensive (TD-)DFT studies in tandem with electrochemical experiments were employed to demonstrate the generality of the reported behavior across perfunctionalized B12(OR)12 clusters (R = aryl or alkyl). While the spin density of radical cationic clusters is delocalized in the core region, the oxidation brings about notable gains of positive partial charges on the supporting groups whose electronics can readily tune the redox potential of the 0/•+ couple. The underlying changes of frontier orbitals were elucidated, and the resulting [B12(OR)12]•+ species manifest a general diagnostic absorption as a consequence of mixed local/charge-transfer excitations.
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Affiliation(s)
- Bo Li
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Xinglong Zhang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Julia M Stauber
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Thomas F Miller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
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26
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Lu Y, Wang JY, Pei J. Achieving Efficient n-Doping of Conjugated Polymers by Molecular Dopants. Acc Chem Res 2021; 54:2871-2883. [PMID: 34152131 DOI: 10.1021/acs.accounts.1c00223] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
ConspectusMolecular doping is one of the most central propositions in the field of organic electronics. Unlike classical inorganic semiconductors doped by atomic substitution, organic conjugated materials react with molecular dopants, and then intermolecular charge transfer is involved within. Therefore, the complex noncovalent interactions between two components often cause the molecular dopant to destroy the orderly stacking of the host organic materials and reduce the original properties of the material, such as carrier mobility, which here we call the "doping dilemma." Recently, many studies focus on improving p-doping efficiency and electrical conductivity of doped conjugated polymers; however, the development of n-type molecular doping currently lags far behind that of its p-counterpart. It is well-known that both efficient p- and n-type molecular doping are indispensable in various organic electronic devices, including light-emitting diodes, photovoltaics, field-effect transistors, and thermoelectrics. It is thus an urgent requirement to achieve efficient n-doping in conjugated polymers.In this Account, we give a brief overview of our efforts to improve the n-doping efficiency in conjugated polymers with several strategies from the aspects of the polymer/dopant molecular design and the exploration of the n-type molecular doping mechanism and charge transport mechanism in n-doped organic materials. For the conjugated polymer engineering, we first demonstrate that increasing the electron affinity of the host polymer through halogen substitution can boost the n-doping efficiency. Still, the rigid coplanar backbones of conjugated polymers play a crucial role in the polaron delocalization and final electrical performance. In addition, we emphasize the importance of morphology control in the doped polymers to address the "doping dilemma." For n-dopants designing, we summarize some basic guidelines from molecular sizes and shapes, the interaction between dopants (or dopant cations) and polymers, and the effects of dopants on morphology to design high-efficacy n-type molecular dopants. We propose that the polymers and the dopants need to be treated as a whole system; while enhancing the ionization efficiency, more attention should be paid to the carrierization (free-carrier generation) efficiency of these binary systems. In the end, we adopt the n-type polymer thermoelectric material as an example to discuss the grand challenges encountered in practical applications of n-doped conjugated polymers. The air stability and micrometer-thick thermo-leg processing of n-doped polymers are highlighted for thermoelectric applications. It is our hope that this Account showcases a blueprint for rational approaches and a deep understanding toward the design and development of efficient n-doping in conjugated polymers, bringing n-doped organic materials into the next era.
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Affiliation(s)
- Yang Lu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jie-Yu Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jian Pei
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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27
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Ghosh R, Paesani F. Unraveling the effect of defects, domain size, and chemical doping on photophysics and charge transport in covalent organic frameworks. Chem Sci 2021; 12:8373-8384. [PMID: 34221318 PMCID: PMC8221171 DOI: 10.1039/d1sc01262b] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/12/2021] [Indexed: 11/21/2022] Open
Abstract
Understanding the underlying physical mechanisms that govern charge transport in two-dimensional (2D) covalent organic frameworks (COFs) will facilitate the development of novel COF-based devices for optoelectronic and thermoelectric applications. In this context, the low-energy mid-infrared absorption contains valuable information about the structure-property relationships and the extent of intra- and inter-framework "hole" polaron delocalization in doped and undoped polymeric materials. In this study, we provide a quantitative characterization of the intricate interplay between electronic defects, domain sizes, pore volumes, chemical dopants, and three dimensional anisotropic charge migration in 2D COFs. We compare our simulations with recent experiments on doped COF films and establish the correlations between polaron coherence, conductivity, and transport signatures. By obtaining the first quantitative agreement with the measured absorption spectra of iodine doped (aza)triangulene-based COF, we highlight the fundamental differences between the underlying microstructure, spectral signatures, and transport physics of polymers and COFs. Our findings provide conclusive evidence of why iodine doped COFs exhibit lower conductivity compared to doped polythiophenes. Finally, we propose new research directions to address existing limitations and improve charge transport in COFs for applications in functional molecular electronic devices.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla California 92093 USA
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla California 92093 USA
- San Diego Supercomputer Center, University of California San Diego La Jolla California 92093 USA
- Materials Science and Engineering, University of California San Diego La Jolla California 92093 USA
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28
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Kang HS, Peurifoy S, Zhang B, Ferguson AJ, Reid OG, Nuckolls C, Blackburn JL. Linking optical spectra to free charges in donor/acceptor heterojunctions: cross-correlation of transient microwave and optical spectroscopy. MATERIALS HORIZONS 2021; 8:1509-1517. [PMID: 34846459 DOI: 10.1039/d0mh01810d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The primary photoexcited species in excitonic semiconductors is a bound electron-hole pair, or exciton. An important strategy for producing separated electrons and holes in photoexcited excitonic semiconductors is the use of donor/acceptor heterojunctions, but the degree to which the carriers can escape their mutual Coulomb attraction is still debated for many systems. Here, we employ a combined pump-probe ultrafast transient absorption (TA) spectroscopy and time-resolved microwave conductivity (TRMC) study on a suite of model excitonic heterojunctions consisting of mono-chiral semiconducting single-walled carbon nanotube (s-SWCNT) electron donors and small-molecule electron acceptors. Comparison of the charge-separated state dynamics between TA and TRMC photoconductance reveals a quantitative match over the 0.5 microsecond time scale. Charge separation yields derived from TA allow extraction of s-SWCNT hole mobilities of ca. 1.5 cm2 V-1 s-1 (at 9 GHz) by TRMC. The correlation between the techniques conclusively demonstrates that photoinduced charge carriers separated across these heterojunctions do not form bound charge transfer states, but instead form free/mobile charge carriers.
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Affiliation(s)
- Hyun Suk Kang
- National Renewable Energy Laboratory, Golden, CO 80401, USA.
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29
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Marqués PS, Londi G, Yurash B, Nguyen TQ, Barlow S, Marder SR, Beljonne D. Understanding how Lewis acids dope organic semiconductors: a "complex" story. Chem Sci 2021; 12:7012-7022. [PMID: 34123329 PMCID: PMC8153436 DOI: 10.1039/d1sc01268a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/15/2021] [Indexed: 01/15/2023] Open
Abstract
We report on computational studies of the potential of three borane Lewis acids (LAs) (B(C6F5)3 (BCF), BF3, and BBr3) to form stable adducts and/or to generate positive polarons with three different semiconducting π-conjugated polymers (PFPT, PCPDTPT and PCPDTBT). Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations based on range-separated hybrid (RSH) functionals provide insight into changes in the electronic structure and optical properties upon adduct formation between LAs and the two polymers containing pyridine moieties, PFPT and PCPDTPT, unravelling the complex interplay between partial hybridization, charge transfer and changes in the polymer backbone conformation. We then assess the potential of BCF to induce p-doping in PCPDTBT, which does not contain pyridine groups, by computing the energetics of various reaction mechanisms proposed in the literature. We find that reaction of BCF(OH2) to form protonated PCPDTBT and [BCF(OH)]-, followed by electron transfer from a pristine to a protonated PCPDTBT chain is highly endergonic, and thus unlikely at low doping concentration. The theoretical and experimental data can, however, be reconciled if one considers the formation of [BCF(OH)BCF]- or [BCF(OH)(OH2)BCF]- counterions rather than [BCF(OH)]- and invokes subsequent reactions resulting in the elimination of H2.
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Affiliation(s)
- Pablo Simón Marqués
- Laboratoire MOLTECH-Anjou, UMR CNRS 6200, UNIV Angers, SFR MATRIX 2 Bd Lavoisier 49045 Angers Cedex France
| | - Giacomo Londi
- Laboratory for Chemistry of Novel Materials, University of Mons Place du Parc, 20 7000 Mons Belgium
| | - Brett Yurash
- Center for Polymers and Organic Solids, Department of Chemistry & Biochemistry, University of California Santa Barbara California 93106 USA
| | - Thuc-Quyen Nguyen
- Center for Polymers and Organic Solids, Department of Chemistry & Biochemistry, University of California Santa Barbara California 93106 USA
| | - Stephen Barlow
- Center for Organic Photonics and Electronics, School of Chemistry and Biochemistry, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
| | - Seth R Marder
- Center for Organic Photonics and Electronics, School of Chemistry and Biochemistry, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons Place du Parc, 20 7000 Mons Belgium
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30
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Tait CE, Reckwitz A, Arvind M, Neher D, Bittl R, Behrends J. Spin-spin interactions and spin delocalisation in a doped organic semiconductor probed by EPR spectroscopy. Phys Chem Chem Phys 2021; 23:13827-13841. [PMID: 34151324 DOI: 10.1039/d1cp02133h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The enhancement and control of the electrical conductivity of organic semiconductors is fundamental for their use in optoelectronic applications and can be achieved by molecular doping, which introduces additional charge carriers through electron transfer between a dopant molecule and the organic semiconductor. Here, we use Electron Paramagnetic Resonance (EPR) spectroscopy to characterise the unpaired spins associated with the charges generated by molecular doping of the prototypical organic semiconductor poly(3-hexylthiophene) (P3HT) with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and tris(pentafluorophenyl)borane (BCF). The EPR results reveal the P3HT radical cation as the only paramagnetic species in BCF-doped P3HT films and show evidence for increased mobility of the detected spins at high doping concentrations as well as formation of antiferromagnetically coupled spin pairs leading to decreased spin concentrations at low temperatures. The EPR signature for F4TCNQ-doped P3HT is found to be determined by spin exchange between P3HT radical cations and F4TCNQ radical anions. Results from continuous-wave and pulse EPR measurements suggest the presence of the unpaired spin on P3HT in a multitude of environments, ranging from free P3HT radical cations with similar properties to those observed in BCF-doped P3HT, to pairs of dipolar and exchange-coupled spins on P3HT and the dopant anion. Characterisation of the proton hyperfine interactions by ENDOR allowed quantification of the extent of spin delocalisation and revealed reduced delocalisation in the F4TCNQ-doped P3HT films.
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Affiliation(s)
- Claudia E Tait
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany. and Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QZ Oxford, UK
| | - Anna Reckwitz
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
| | - Malavika Arvind
- Institute of Physics and Astronomy, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Dieter Neher
- Institute of Physics and Astronomy, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Robert Bittl
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
| | - Jan Behrends
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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31
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Voss MG, Challa JR, Scholes DT, Yee PY, Wu EC, Liu X, Park SJ, León Ruiz O, Subramaniyan S, Chen M, Jenekhe SA, Wang X, Tolbert SH, Schwartz BJ. Driving Force and Optical Signatures of Bipolaron Formation in Chemically Doped Conjugated Polymers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2000228. [PMID: 33296113 DOI: 10.1002/adma.202000228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 10/11/2020] [Indexed: 06/12/2023]
Abstract
Molecular dopants are often added to semiconducting polymers to improve electrical conductivity. However, the use of such dopants does not always produce mobile charge carriers. In this work, ultrafast spectroscopy is used to explore the nature of the carriers created following doping of conjugated push-pull polymers with both F4 TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) and FeCl3 . It is shown that for one particular push-pull material, the charge carriers created by doping are entirely non-conductive bipolarons and not single polarons, and that transient absorption spectroscopy following excitation in the infrared can readily distinguish the two types of charge carriers. Based on density functional theory calculations and experiments on multiple push-pull conjugated polymers, it is argued that the size of the donor push units determines the relative stabilities of polarons and bipolarons, with larger donor units stabilizing the bipolarons by providing more area for two charges to co-reside.
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Affiliation(s)
- Matthew G Voss
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - J Reddy Challa
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - D Tyler Scholes
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Patrick Y Yee
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Eric C Wu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Xiao Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Sanghyun J Park
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Omar León Ruiz
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Selvam Subramaniyan
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
| | - Mengdan Chen
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Samson A Jenekhe
- Department of Chemical Engineering and Department of Chemistry, University of Washington, Seattle, WA, 98195-1750, USA
| | - Xiaolin Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Sarah H Tolbert
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, 90095-8352, USA
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095-1595, USA
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, 90095-8352, USA
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32
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Koopmans M, Leiviskä MAT, Liu J, Dong J, Qiu L, Hummelen JC, Portale G, Heiber MC, Koster LJA. Electrical Conductivity of Doped Organic Semiconductors Limited by Carrier-Carrier Interactions. ACS APPLIED MATERIALS & INTERFACES 2020; 12:56222-56230. [PMID: 33263385 PMCID: PMC7747224 DOI: 10.1021/acsami.0c15490] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/20/2020] [Indexed: 05/30/2023]
Abstract
High electrical conductivity is a prerequisite for improving the performance of organic semiconductors for various applications and can be achieved through molecular doping. However, often the conductivity is enhanced only up to a certain optimum doping concentration, beyond which it decreases significantly. We combine analytical work and Monte Carlo simulations to demonstrate that carrier-carrier interactions can cause this conductivity decrease and reduce the maximum conductivity by orders of magnitude, possibly in a broad range of materials. Using Monte Carlo simulations, we disentangle the effect of carrier-carrier interactions from carrier-dopant interactions. Coulomb potentials of ionized dopants are shown to decrease the conductivity, but barely influence the trend of conductivity versus doping concentration. We illustrate these findings using a doped fullerene derivative for which we can correctly estimate the carrier density at which the conductivity maximizes. We use grazing-incidence wide-angle X-ray scattering to show that the decrease of the conductivity cannot be explained by changes to the microstructure. We propose the reduction of carrier-carrier interactions as a strategy to unlock higher-conductivity organic semiconductors.
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Affiliation(s)
- Marten Koopmans
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
| | - Miina A. T. Leiviskä
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
| | - Jian Liu
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
| | - Jingjin Dong
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
| | - Li Qiu
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
- Stratingh
Institute for Chemistry, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Jan C. Hummelen
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
- Stratingh
Institute for Chemistry, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Giuseppe Portale
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
| | - Michael C. Heiber
- Center
for Hierarchical Materials Design, Northwestern
University, Evanston, Illinois 60208, United
States
| | - L. Jan Anton Koster
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen 9747 AG, The Netherlands
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33
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Sahalianov I, Hynynen J, Barlow S, Marder SR, Müller C, Zozoulenko I. UV-to-IR Absorption of Molecularly p-Doped Polythiophenes with Alkyl and Oligoether Side Chains: Experiment and Interpretation Based on Density Functional Theory. J Phys Chem B 2020; 124:11280-11293. [PMID: 33237790 PMCID: PMC7872427 DOI: 10.1021/acs.jpcb.0c08757] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/04/2020] [Indexed: 11/28/2022]
Abstract
The UV-to-IR transitions in p-doped poly(3-hexylthiophene) (P3HT) with alkyl side chains and polar polythiophene with tetraethylene glycol side chains are studied experimentally by means of the absorption spectroscopy and computationally using density functional theory (DFT) and tight-binding DFT. The evolution of electronic structure is calculated as the doping level is varied, while the roles of dopant ions, chain twisting, and π-π stacking are also considered, each of these having the effect of broadening the absorption peaks while not significantly changing their positions. The calculated spectra are found to be in good agreement with experimental spectra obtained for the polymers doped with a molybdenum dithiolene complex. As in other DFT studies of doped conjugated polymers, the electronic structure and assignment of optical transitions that emerge are qualitatively different from those obtained through earlier "traditional" approaches. In particular, the two prominent bands seen for the p-doped materials are present for both polarons and bipolarons/polaron pairs. The lowest energy of these transitions is due to excitation from the valence band to a spin-resolved orbitals located in the gap between the bands. The higher-energy band is a superposition of excitation from the valence band to a spin-resolved orbitals in the gap and an excitation between bands.
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Affiliation(s)
- Ihor Sahalianov
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
| | - Jonna Hynynen
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Göteborg, Sweden
| | - Stephen Barlow
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Seth R. Marder
- School
of Chemistry and Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Christian Müller
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Göteborg, Sweden
| | - Igor Zozoulenko
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 60174 Norrköping, Sweden
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34
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Abstract
ConspectusExcitons and polarons play a central role in the electronic and optical properties of organic semiconducting polymers and molecular aggregates and are of fundamental importance in understanding the operation of organic optoelectronic devices such as solar cells and light-emitting diodes. For many conjugated organic molecules and polymers, the creation of neutral electronic excitations or ionic radicals is associated with significant nuclear relaxation, the bulk of which occurs along the vinyl-stretching mode or the aromatic-quinoidal stretching mode when conjugated rings are present. Within a polymer chain or molecular aggregate, nuclear relaxation competes with energy- and charge-transfer, mediated by electronic interactions between the constituent units (repeat units for polymers and individual chromophores for a molecular aggregate); for neutral electronic excitations, such inter-unit interactions lead to extended excited states or excitons, while for positive (or negative) charges, interactions lead to delocalized hole (or electron) polarons. The electronic coupling as well as the local coupling between electronic and nuclear degrees of freedom in both excitons and polarons can be described with a Holstein Hamiltonian. However, although excitons and polarons derive from similarly structured Hamiltonians, their optical signatures are quite distinct, largely due to differing ground states and optical selection rules.In this Account, we explore the similarities and differences in the spectral response of excitons and polarons in organic polymers and molecular aggregates. We limit our analysis to the subspace of excitons and hole polarons containing at most one excitation; hence we omit the influence of bipolarons, biexcitons, and higher multiparticle excitations. Using a generic linear array of coupled units as a model host for both excitons and polarons, we compare and contrast the optical responses of both quasiparticles, with a particular emphasis on the spatial coherence length, the length over which an exciton or polaron possesses wave-like properties important for more efficient transport. For excitons, the UV-vis absorption spectrum is generally represented by a distorted vibronic progression with H-like or J-like signatures depending on the sign of the electronic coupling, Jex. The spectrum broadens with increasing site disorder, with the spectral area preserved due to an oscillator strength sum rule. For (hole) polarons, the generally stronger electronic coupling results in a mid-IR spectrum consisting of a narrow, low-energy peak (A) with energy near a vibrational quantum of the vinyl stretching mode, and a broader, higher-energy feature (B). In contrast to the UV-vis spectrum, the mid-IR spectrum is invariant to the sign of the electronic coupling, th, and completely resistant to long-range disorder, where it remains entirely homogeneously broadened. Even in the presence of short-range disorder, the width of peak A remains surprisingly narrow as long as |th| remains sufficiently large, a property that can be understood in terms of Herzberg-Teller coupling. Unlike for excitons, for polarons, the absorption spectral area decreases with increasing short-range disorder σ (i.e., there is no oscillator sum rule) reflective of a decreasing polaron coherence length. The intensity of the low-energy peak A in relation to B is an important signature of polaron coherence. By contrast, for excitons, the absorption spectrum contains no unambiguous signs of exciton coherence. One must instead resort to the shape of the steady-state photoluminescence spectrum. The Holstein-based model has been highly successful in accounting for the spectral properties of molecular aggregates as well as conjugated polymers like poly(3-hexylthiophene) (P3HT) in the mid-IR and UV-vis spectral regions.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Frank C. Spano
- Department of Chemistry Temple University, Philadelphia, Pennsylvania 19122, United States
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35
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Lu Y, Yu ZD, Liu Y, Ding YF, Yang CY, Yao ZF, Wang ZY, You HY, Cheng XF, Tang B, Wang JY, Pei J. The Critical Role of Dopant Cations in Electrical Conductivity and Thermoelectric Performance of n-Doped Polymers. J Am Chem Soc 2020; 142:15340-15348. [DOI: 10.1021/jacs.0c05699] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Yang Lu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Zi-Di Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Yi Liu
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial, Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, People’s Republic of China
| | - Yi-Fan Ding
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Chi-Yuan Yang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Ze-Fan Yao
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Zi-Yuan Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Hao-Yang You
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Xiu-Fen Cheng
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial, Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, People’s Republic of China
| | - Bo Tang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial, Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, Shandong 250014, People’s Republic of China
| | - Jie-Yu Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
| | - Jian Pei
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center of Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China
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36
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Untilova V, Hynynen J, Hofmann AI, Scheunemann D, Zhang Y, Barlow S, Kemerink M, Marder SR, Biniek L, Müller C, Brinkmann M. High Thermoelectric Power Factor of Poly(3-hexylthiophene) through In-Plane Alignment and Doping with a Molybdenum Dithiolene Complex. Macromolecules 2020; 53:6314-6321. [PMID: 32913375 PMCID: PMC7472519 DOI: 10.1021/acs.macromol.0c01223] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/22/2020] [Indexed: 12/27/2022]
Abstract
We report a record thermoelectric power factor of up to 160 μW m-1 K-2 for the conjugated polymer poly(3-hexylthiophene) (P3HT). This result is achieved through the combination of high-temperature rubbing of thin films together with the use of a large molybdenum dithiolene p-dopant with a high electron affinity. Comparison of the UV-vis-NIR spectra of the chemically doped samples to electrochemically oxidized material reveals an oxidation level of 10%, i.e., one polaron for every 10 repeat units. The high power factor arises due to an increase in the charge-carrier mobility and hence electrical conductivity along the rubbing direction. We conclude that P3HT, with its facile synthesis and outstanding processability, should not be ruled out as a potential thermoelectric material.
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Affiliation(s)
| | - Jonna Hynynen
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Göteborg, Sweden
| | - Anna I. Hofmann
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Göteborg, Sweden
| | - Dorothea Scheunemann
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Göteborg, Sweden
| | - Yadong Zhang
- School
of Chemistry & Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Stephen Barlow
- School
of Chemistry & Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Martijn Kemerink
- Centre
for Advanced Materials, Heidelberg University, 69120 Heidelberg, Germany
| | - Seth R. Marder
- School
of Chemistry & Biochemistry and Center for Organic Photonics and
Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - Laure Biniek
- CNRS,
ICS UPR 22, Université de Strasbourg, F-67000 Strasbourg, France
| | - Christian Müller
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Göteborg, Sweden
| | - Martin Brinkmann
- CNRS,
ICS UPR 22, Université de Strasbourg, F-67000 Strasbourg, France
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37
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Stauber JM, Schwan J, Zhang X, Axtell JC, Jung D, McNicholas BJ, Oyala PH, Martinolich AJ, Winkler JR, See KA, Miller TF, Gray HB, Spokoyny AM. A Super-Oxidized Radical Cationic Icosahedral Boron Cluster. J Am Chem Soc 2020; 142:12948-12953. [PMID: 32646209 DOI: 10.1021/jacs.0c06159] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While the icosahedral closo-[B12H12]2- cluster does not display reversible electrochemical behavior, perfunctionalization of this species via substitution of all 12 B-H vertices with alkoxy or benzyloxy (OR) substituents engenders reversible redox chemistry, providing access to clusters in the dianionic, monoanionic, and neutral forms. Here, we evaluated the electrochemical behavior of the electron-rich B12(O-3-methylbutyl)12 (1) cluster and discovered that a new reversible redox event that gives rise to a fourth electronic state is accessible through one-electron oxidation of the neutral species. Chemical oxidation of 1 with [N(2,4-Br2C6H3)3]•+ afforded the isolable [1]•+ cluster, which is the first example of an open-shell cationic B12 cluster in which the unpaired electron is proposed to be delocalized throughout the boron cluster core. The oxidation of 1 is also chemically reversible, where treatment of [1]•+ with ferrocene resulted in its reduction back to 1. The identity of [1]•+ is supported by EPR, UV-vis, multinuclear NMR (1H, 11B), and X-ray photoelectron spectroscopic characterization.
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Affiliation(s)
- Julia M Stauber
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Josef Schwan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Xinglong Zhang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Jonathan C Axtell
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Dahee Jung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
| | - Brendon J McNicholas
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Paul H Oyala
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Andrew J Martinolich
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Jay R Winkler
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Kimberly A See
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Thomas F Miller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Harry B Gray
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095, United States
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38
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Aubry TJ, Winchell KJ, Salamat CZ, Basile VM, Lindemuth JR, Stauber JM, Axtell JC, Kubena RM, Phan MD, Bird MJ, Spokoyny AM, Tolbert SH, Schwartz BJ. Tunable Dopants with Intrinsic Counterion Separation Reveal the Effects of Electron Affinity on Dopant Intercalation and Free Carrier Production in Sequentially Doped Conjugated Polymer Films. ADVANCED FUNCTIONAL MATERIALS 2020; 30:2001800. [PMID: 32684909 PMCID: PMC7357248 DOI: 10.1002/adfm.202001800] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
Carrier mobility in doped conjugated polymers is limited by Coulomb interactions with dopant counterions. This complicates studying the effect of the dopant's oxidation potential on carrier generation because different dopants have different Coulomb interactions with polarons on the polymer backbone. Here, dodecaborane (DDB)-based dopants are used, which electrostatically shield counterions from carriers and have tunable redox potentials at constant size and shape. DDB dopants produce mobile carriers due to spatial separation of the counterion, and those with greater energetic offsets produce more carriers. Neutron reflectometry indicates that dopant infiltration into conjugated polymer films is redox-potential-driven. Remarkably, X-ray scattering shows that despite their large 2-nm size, DDBs intercalate into the crystalline polymer lamellae like small molecules, indicating that this is the preferred location for dopants of any size. These findings elucidate why doping conjugated polymers usually produces integer, rather than partial charge transfer: dopant counterions effectively intercalate into the lamellae, far from the polarons on the polymer backbone. Finally, it is shown that the IR spectrum provides a simple way to determine polaron mobility. Overall, higher oxidation potentials lead to higher doping efficiencies, with values reaching 100% for driving forces sufficient to dope poorly crystalline regions of the film.
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Affiliation(s)
- Taylor J. Aubry
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | - K. J. Winchell
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | - Charlene Z. Salamat
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | - Victoria M. Basile
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | | | - Julia M. Stauber
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | - Jonathan C. Axtell
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | - Rebecca M. Kubena
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
| | - Minh D. Phan
- Neutron Scattering DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Matthew J. Bird
- Chemistry DepartmentBrookhaven National LaboratoryUptonNY11973USA
| | - Alexander M. Spokoyny
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
- California NanoSystems InstituteUniversity of California, Los AngelesLos AngelesCA90095‐7227USA
| | - Sarah H. Tolbert
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
- California NanoSystems InstituteUniversity of California, Los AngelesLos AngelesCA90095‐7227USA
- Department of Materials Science and EngineeringUniversity of California, Los AngelesLos AngelesCA90095‐1595USA
| | - Benjamin J. Schwartz
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesCA90095‐1569USA
- California NanoSystems InstituteUniversity of California, Los AngelesLos AngelesCA90095‐7227USA
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39
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Shi W, Yildirim E, Wu G, Wong ZM, Deng T, Wang J, Xu J, Yang S. The Role of Electrostatic Interaction between Free Charge Carriers and Counterions in Thermoelectric Power Factor of Conducting Polymers: From Crystalline to Polycrystalline Domains. ADVANCED THEORY AND SIMULATIONS 2020. [DOI: 10.1002/adts.202000015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Wen Shi
- Institute of High Performance ComputingAgency for Science, Technology and Research 1 Fusionopolis Way, #16‐16 Connexis Singapore 138632 Republic of Singapore
| | - Erol Yildirim
- Institute of High Performance ComputingAgency for Science, Technology and Research 1 Fusionopolis Way, #16‐16 Connexis Singapore 138632 Republic of Singapore
- Department of ChemistryMiddle East Technical University Ankara 06800 Turkey
| | - Gang Wu
- Institute of High Performance ComputingAgency for Science, Technology and Research 1 Fusionopolis Way, #16‐16 Connexis Singapore 138632 Republic of Singapore
| | - Zicong Marvin Wong
- Institute of High Performance ComputingAgency for Science, Technology and Research 1 Fusionopolis Way, #16‐16 Connexis Singapore 138632 Republic of Singapore
| | - Tianqi Deng
- Institute of High Performance ComputingAgency for Science, Technology and Research 1 Fusionopolis Way, #16‐16 Connexis Singapore 138632 Republic of Singapore
| | - Jian‐Sheng Wang
- Department of PhysicsNational University of Singapore 2 Science Drive 3 Singapore 117551 Republic of Singapore
| | - Jianwei Xu
- Institute of Materials Research and EngineeringAgency for Science, Technology and Research 2 Fusionopolis Way, #08‐03 Innovis Singapore 138634 Republic of Singapore
| | - Shuo‐Wang Yang
- Institute of High Performance ComputingAgency for Science, Technology and Research 1 Fusionopolis Way, #16‐16 Connexis Singapore 138632 Republic of Singapore
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40
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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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41
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Li H, DeCoster ME, Ming C, Wang M, Chen Y, Hopkins PE, Chen L, Katz HE. Enhanced Molecular Doping for High Conductivity in Polymers with Volume Freed for Dopants. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b02048] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Hui Li
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Mallory E. DeCoster
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Chen Ming
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Mengdi Wang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yanling Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Patrick E. Hopkins
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Lidong Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Howard E. Katz
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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42
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Yan H, Ma W. Making weak dopants strong. NATURE MATERIALS 2019; 18:1269-1270. [PMID: 31527811 DOI: 10.1038/s41563-019-0493-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Han Yan
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China
| | - Wei Ma
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China.
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43
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Yee PY, Scholes DT, Schwartz BJ, Tolbert SH. Dopant-Induced Ordering of Amorphous Regions in Regiorandom P3HT. J Phys Chem Lett 2019; 10:4929-4934. [PMID: 31382748 DOI: 10.1021/acs.jpclett.9b02070] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Despite the fact that molecular doping of semiconducting polymers has emerged as a valuable strategy for improving the performance of organic electronic devices, the fundamental dopant-polymer interactions are not fully understood. Here we use 2-D grazing incidence wide-angle X-ray scattering (GIWAXS) to demonstrate that adding oxidizing small-molecule dopants, such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) and FeCl3, into the amorphous conjugated polymer, regiorandom poly(3-hexylthiophene-2,5-diyl) (RRa-P3HT), improves polymer ordering and induces a change in domain orientation from isotropic to mostly edge-on. Doping thus causes RRa-P3HT to behave similarly to the more ordered regioregular P3HT. By comparing the optical, electrical, and structural properties of RRa-P3HT films doped with F4TNCQ and FeCl3 and those infiltrated with 7,7,8,8-tetracyanoquinodimethane (TCNQ), which occupies a similar volume as F4TCNQ but does not dope RRa-P3HT, we show that the increased ordering results not from the ability of the dopant to fill space but instead from the need to delocalize charge on the polymer in more than one dimension.
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Affiliation(s)
- Patrick Y Yee
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - D Tyler Scholes
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Sarah H Tolbert
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California 90095-1595, United States
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44
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Axtell JC, Messina MS, Liu JY, Galaktionova D, Schwan J, Porter TM, Savage MD, Wixtrom AI, Rheingold AL, Kubiak CP, Winkler JR, Gray HB, Král P, Alexandrova AN, Spokoyny AM. Photooxidative Generation of Dodecaborate-Based Weakly Coordinating Anions. Inorg Chem 2019; 58:10516-10526. [PMID: 31247818 DOI: 10.1021/acs.inorgchem.9b00935] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Redox-active proanions of the type B12(OCH2Ar)12 [Ar = C6F5 (1), 4-CF3C6H4 (2), 3,5-(CF3)2C6H3 (3)] are introduced in the context of an experimental and computational study of the visible-light-initiated polymerization of a family of styrenes. Neutral, air-stable proanions 1-3 were found to initiate styrene polymerization through single-electron oxidation under blue-light irradiation, resulting in polymers with number-average molecular weights (Mn) ranging from ∼6 to 100 kDa. Shorter polymer products were observed in the majority of experiments, except in the case of monomers containing 4-X (X = F, Cl, Br) substituents on the styrene monomer when polymerized in the presence of 1 in CH2Cl2. Only under these specific conditions are longer polymers (>100 kDa) observed, strongly supporting the formulation that reaction conditions significantly modulate the degree of ion pairing between the dodecaborate anion and cationic chain end. This also suggests that 1-3 behave as weakly coordinating anions (WCA) upon one-electron reduction because no incorporation of the cluster-based photoinitiators is observed in the polymeric products analyzed. Overall, this work is a conceptual realization of a single reagent that can serve as a strong photooxidant, subsequently forming a WCA.
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Affiliation(s)
- Jonathan C Axtell
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States
| | - Marco S Messina
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States.,California NanoSystems Institute , University of California, Los Angeles , 570 Westwood Plaza , Los Angeles , California 90095-1569 , United States
| | - Ji-Yuan Liu
- Key Laboratory for Advanced Materials, Center for Computational Chemistry and Research Institute of Industrial Catalysts, School of Molecular Science and Engineering , East China University of Science and Technology , Shanghai 200237 , P. R. China
| | | | - Josef Schwan
- Beckman Institute , California Institute of Technology , Pasadena , California 91115 , United States
| | - Tyler M Porter
- Department of Chemistry and Biochemistry , University of California, San Diego , 9500 Gilman Drive , La Jolla , California 92093 , United States
| | - Miles D Savage
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States
| | - Alex I Wixtrom
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States
| | - Arnold L Rheingold
- Department of Chemistry and Biochemistry , University of California, San Diego , 9500 Gilman Drive , La Jolla , California 92093 , United States
| | - Clifford P Kubiak
- Department of Chemistry and Biochemistry , University of California, San Diego , 9500 Gilman Drive , La Jolla , California 92093 , United States
| | - Jay R Winkler
- Beckman Institute , California Institute of Technology , Pasadena , California 91115 , United States
| | - Harry B Gray
- Beckman Institute , California Institute of Technology , Pasadena , California 91115 , United States
| | | | - Anastassia N Alexandrova
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States.,California NanoSystems Institute , University of California, Los Angeles , 570 Westwood Plaza , Los Angeles , California 90095-1569 , United States
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45
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Barton JL, Wixtrom AI, Kowalski JA, Qian EA, Jung D, Brushett FR, Spokoyny AM. Perfunctionalized Dodecaborate Clusters as Stable Metal-Free Active Materials for Charge Storage. ACS APPLIED ENERGY MATERIALS 2019; 2:4907-4913. [PMID: 33778417 PMCID: PMC7996373 DOI: 10.1021/acsaem.9b00610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report a class of perfunctionalized dodecaborate clusters that exhibit high stability towards high concentration electrochemical cycling. These boron clusters afford several degrees of freedom in material design to tailor properties including solubility and redox potential. The exceptional stability of these clusters was demonstrated using a symmetric flow cell setup for electrochemical cycling between two oxidation states for 45 days, with post-run analysis showing negligible decomposition of the active species (<0.1%). To further probe the limits of this system, a prototype redox flow battery with two different cluster materials was used to determine mutual compatibility. This work effectively illustrates the potential of bespoke boron clusters as robust material platform for electrochemical energy conversion and storage.
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Affiliation(s)
- John L. Barton
- Joint Center for Energy Storage Research, Argonne National Laboratory, 9700 South Class Ave, Bldg. 200, Argonne, Illinois 60439, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139, USA
| | - Alex I. Wixtrom
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA
| | - Jeffrey A. Kowalski
- Joint Center for Energy Storage Research, Argonne National Laboratory, 9700 South Class Ave, Bldg. 200, Argonne, Illinois 60439, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139, USA
| | - Elaine A. Qian
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA
- Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza, Los Angeles, California 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095-1569, USA
| | - Dahee Jung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA
- California NanoSystems Institute, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095-1569, USA
| | - Fikile R. Brushett
- Joint Center for Energy Storage Research, Argonne National Laboratory, 9700 South Class Ave, Bldg. 200, Argonne, Illinois 60439, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139, USA
| | - Alexander M. Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA
- California NanoSystems Institute, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095-1569, USA
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46
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Voss MG, Scholes DT, Challa JR, Schwartz BJ. Ultrafast transient absorption spectroscopy of doped P3HT films: distinguishing free and trapped polarons. Faraday Discuss 2019; 216:339-362. [PMID: 31038132 DOI: 10.1039/c8fd00210j] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It is generally presumed that the vast majority of carriers created by chemical doping of semiconducting polymer films are coulombically trapped by the counteranion, with only a small fraction that are free and responsible for the increased conductivity essential for organic electronic applications. At higher doping levels, it is also possible for bipolarons to form, which are expected to be less conductive than single polarons. Unfortunately, there is no simple way to distinguish free polarons, trapped polarons and bipolarons using steady-state spectroscopy. Thus, in this work, we use ultrafast transient absorption spectroscopy to study the dynamics of polarons in 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TNCQ)-doped films of poly(3-hexylthiophene-2,5-diyl) (P3HT) as a function of dopant concentration and excitation wavelength. When exciting on the red side of the polaron P1 transition, our transient absorption spectra and kinetics match well with what is expected for free 2-D-delocalized polarons; the measurements are not consistent with a recent theory of doped conjugated polymer electronic structure that suggests that the half-filled state lies deeper in the conduction band rather than in the bandgap. As we tune the excitation wavelength to the blue, our measurements reveal an increasing amount of slower transient kinetics that are consistent with the presence of coulombically-trapped polarons rather than bipolarons. Taking advantage of their distinct ultrafast relaxation kinetics as a type of action spectroscopy, we are able to extract the steady-state absorption spectra of free and trapped polarons as a function of dopant concentration. By comparing the results to theoretical models, we determine that in F4TCNQ-doped P3HT films, trapped polarons sit ∼0.4 nm away from the anion while free polarons reside between 0.7 and 0.9 nm from the counteranion. Perhaps counterintuitively, the ratio of trapped to free polarons increases at higher doping levels, an observation that is consistent with a plateau in the concentration-dependent conductivity of F4TCNQ-doped P3HT films.
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Affiliation(s)
- Matthew G Voss
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, CA 90095-1569, USA.
| | - D Tyler Scholes
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, CA 90095-1569, USA.
| | - J Reddy Challa
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, CA 90095-1569, USA.
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, CA 90095-1569, USA.
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