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Yang X, Ye G, Liu J, Chiechi RC, Koster LJA. Carrier-Carrier Repulsion Limits the Conductivity of N-Doped Organic Semiconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2404397. [PMID: 39246234 DOI: 10.1002/adma.202404397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 08/29/2024] [Indexed: 09/10/2024]
Abstract
Molecular doping is a key strategy to enhance the electrical conductivity of organic semiconductors. Typically, the electrical conductivity shows a maximum value upon increased doping, after which the conductivity decreases. This decrease in conductivity is commonly attributed to unfavorable changes in the morphology. However, in recent simulation work, has shown, that the conductivity-at high doping-is instead limited by electron-electron repulsion rather than by morphology, at least for some material combinations. Based on the simulations, this limitation is expected to show up in the dependence of the Seebeck coefficient versus carrier density: the Seebeck coefficient will follow Heike's formula if carrier-carrier repulsion limits the conductivity. Here, the electrical conductivity and Seebeck coefficient are measured as a function of doping for a series of n-type organic semiconductors. Additionally, the resulting carrier density is measured using metal-insulator-semiconductor diodes, which link dopant loading and the number of charge carriers. At high carrier densities, the Seebeck coefficient indeed follows Heike's formula, confirming that the conductivity is limited by carrier-carrier repulsion rather than by morphological effects. This study shows that current models of hopping transport in organic semiconductors may be incomplete. As a result, this study offers novel insights in the design of organic semiconductors.
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Affiliation(s)
- Xuwen Yang
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 3, Groningen, 9747 AG, The Netherlands
| | - Gang Ye
- Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, School of Materials Science and Engineering, Hubei University, Youyi Road 368, Wuhan, 430062, P. R. China
| | - Jian Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
| | - Ryan C Chiechi
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695-8204, USA
| | - L Jan Anton Koster
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 3, Groningen, 9747 AG, The Netherlands
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Su EJ, Chang TW, Lin FY, Lu ST, Tsai YT, Khan S, Weng YC, Shih CC. Efficient Sorting of Semiconducting Single-Walled Carbon Nanotubes in Bio-Renewable Solvents Through Main-Chain Engineering of Conjugated Polymers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2403651. [PMID: 38934537 DOI: 10.1002/smll.202403651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/13/2024] [Indexed: 06/28/2024]
Abstract
Conjugated polymer sorting is recognized as an efficient and scalable method for the selective extraction of semiconducting single-walled carbon nanotubes (s-SWCNTs). However, this process typically requires the use of nonpolar and aromatic solvents as the dispersion medium, which are petroleum-based and carry significant production hazards. Moreover, there is still potential for improving the efficiency of batch purification. Here, this study presents fluorene-based conjugated polymer that integrates diamines containing ethylene glycol chains (ODA) as linkers within the main chain, to effectively extract s-SWCNTs in bio-renewable solvents. The introduction of ODA segments enhances the solubility in bio-renewable solvents, facilitating effective wrapping of s-SWCNTs in polar environments. Additionally, the ODA within the main chain enhances affinity to s-SWCNTs, thereby contributing to increased yields and purity. The polymer achieves a high sorting yield of 55% and a purity of 99.6% in dispersion of s-SWCNTs in 2-Methyltetrahydrofuran. Thin-film transistor arrays fabricated with sorted s-SWCNTs solution through slot-die coating exhibit average charge carrier mobilities of 20-23 cm2 V⁻¹ s⁻¹ and high on/off current ratios exceeding 105 together with high spatial uniformity. This study highlights the viability of bio-renewable solvents in the sorting process, paving the way for the eco-friendly approach to the purification of SWCNTs.
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Affiliation(s)
- En-Jia Su
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Ting-Wei Chang
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Fong-Yi Lin
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Shi-Ting Lu
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Yi-Ting Tsai
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Shahid Khan
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Yu-Ching Weng
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
| | - Chien-Chung Shih
- Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan
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Chen CC, Su SW, Tung YH, Wang PY, Yu SS, Chiu CC, Shih CC, Lin YC. High-Performance Semiconducting Carbon Nanotube Transistors Using Naphthalene Diimide-Based Polymers with Biaxially Extended Conjugated Side Chains. ACS APPLIED MATERIALS & INTERFACES 2024; 16:45275-45288. [PMID: 39137092 PMCID: PMC11367582 DOI: 10.1021/acsami.4c08981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/30/2024] [Accepted: 08/02/2024] [Indexed: 08/15/2024]
Abstract
Polymer-wrapped single-walled carbon nanotubes (SWNTs) are a potential method for obtaining high-purity semiconducting (sc) SWNT solutions. Conjugated polymers (CPs) can selectively sort sc-SWNTs with different chiralities, and the structure of the polymer side chains influences this sorting capability. While extensive research has been conducted on modifying the physical, optical, and electrical properties of CPs through side-chain modifications, the impact of these modifications on the sorting efficiency of sc-SWNTs remains underexplored. This study investigates the introduction of various conjugated side chains into naphthalene diimide-based CPs to create a biaxially extended conjugation pattern. The CP with a branched conjugated side chain (P3) exhibits reduced aggregation, resulting in improved wrapping ability and the formation of larger bundles of high-purity sc-SWNTs. Grazing incidence X-ray diffraction analysis confirms that the potential interaction between sc-SWNTs and CPs occurs through π-π stacking. The field-effect transistor device fabricated with P3/sc-SWNTs demonstrates exceptional performance, with a significantly enhanced hole mobility of 4.72 cm2 V-1 s-1 and high endurance/bias stability. These findings suggest that biaxially extended side-chain modification is a promising strategy for improving the sorting efficiency and performance of sc-SWNTs by using CPs. This achievement can facilitate the development of more efficient and stable electronic devices.
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Affiliation(s)
- Chun-Chi Chen
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Shang-Wen Su
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Yi-Hsuan Tung
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Po-Yuan Wang
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Sheng-Sheng Yu
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Chi-Cheng Chiu
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
| | - Chien-Chung Shih
- Department
of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan
| | - Yan-Cheng Lin
- Department
of Chemical Engineering, National Cheng
Kung University, Tainan 70101, Taiwan
- Advanced
Research Center for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan
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Mastrocinque F, Bullard G, Alatis JA, Albro JA, Nayak A, Williams NX, Kumbhar A, Meikle H, Widel ZXW, Bai Y, Harvey AK, Atkin JM, Waldeck DH, Franklin AD, Therien MJ. Band gap opening of metallic single-walled carbon nanotubes via noncovalent symmetry breaking. Proc Natl Acad Sci U S A 2024; 121:e2317078121. [PMID: 38466848 PMCID: PMC10962935 DOI: 10.1073/pnas.2317078121] [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: 10/02/2023] [Accepted: 02/03/2024] [Indexed: 03/13/2024] Open
Abstract
Covalent bonding interactions determine the energy-momentum (E-k) dispersion (band structure) of solid-state materials. Here, we show that noncovalent interactions can modulate the E-k dispersion near the Fermi level of a low-dimensional nanoscale conductor. We demonstrate that low energy band gaps may be opened in metallic carbon nanotubes through polymer wrapping of the nanotube surface at fixed helical periodicity. Electronic spectral, chiro-optic, potentiometric, electronic device, and work function data corroborate that the magnitude of band gap opening depends on the nature of the polymer electronic structure. Polymer dewrapping reverses the conducting-to-semiconducting phase transition, restoring the native metallic carbon nanotube electronic structure. These results address a long-standing challenge to develop carbon nanotube electronic structures that are not realized through disruption of π conjugation, and establish a roadmap for designing and tuning specialized semiconductors that feature band gaps on the order of a few hundred meV.
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Affiliation(s)
| | - George Bullard
- Department of Chemistry, Duke University, Durham, NC27708
| | | | - Joseph A. Albro
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA15260
| | - Animesh Nayak
- Department of Chemistry, Duke University, Durham, NC27708
| | - Nicholas X. Williams
- Department of Electrical and Computer Engineering, Duke University, Durham, NC27708
| | - Amar Kumbhar
- Department of Chemistry, Chapel Hill Analytical and Nanofabrication Laboratory, University of North Carolina, Chapel Hill, NC27599
| | - Hope Meikle
- Department of Chemistry, Duke University, Durham, NC27708
- Department of Electrical and Computer Engineering, Duke University, Durham, NC27708
| | | | - Yusong Bai
- Department of Chemistry, Duke University, Durham, NC27708
| | - Alexis K. Harvey
- Department of Chemistry, University of North Carolina, Chapel Hill, NC27599
| | - Joanna M. Atkin
- Department of Chemistry, University of North Carolina, Chapel Hill, NC27599
| | - David H. Waldeck
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA15260
| | - Aaron D. Franklin
- Department of Chemistry, Duke University, Durham, NC27708
- Department of Electrical and Computer Engineering, Duke University, Durham, NC27708
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