| 1. |
- Can, Ayse, et al.
(författare)
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Indenofluorenes for organic optoelectronics: the dance of fused five- and six-membered rings enabling structural versatility
- 2022
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 10:22, s. 8496-8535
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Forskningsöversikt (refereegranskat)abstract
- Polycyclic pi-conjugated hydrocarbons (PCHs), either unfunctionalized or structurally modified derivatives, have attracted tremendous interest in the past few decades as high-performance semiconductors for use in new generations of organic (opto)electronic devices. Among several PCHs realized to date, the 6-5-6-5-6 pi-fused-ring backbone of indenofluorene (IF) stands out as a unique semiconducting architecture with great structural and property versatility affording six different regioisomers, diverse functionalization/substitution positions, pi-conjugation/delocalization patterns, aromatic behaviors, and electronic structures. In this review, we summarize and analyze the historical and recent advances in the design and implementation of IF-based semiconductors in organic transistor and solar cell devices, as well as in understanding the chemical structure-molecular property-semiconductivity relationships. Following an introduction to the fascinating properties of an IF pi-framework that distinguishes this core among PCHs, we present IF-based semiconductors and discuss their properties by classifying them into four main families (IF-diones, IF-DCVs/IF-TTFs, pi-IFs, and (un)substituted DH-IFs) considering whether methylene or methine C-bridges are present and how these positions are functionalized or substituted. For each family, design and synthetic approaches, molecular properties, and transistor/solar cell device applicability and/or performance are reviewed and discussed. At the end, we conclude with a section discussing the challenges and opportunities for future progress of IF-based semiconductor materials and related (opto)electronic technologies.
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| 2. |
- Chen, Jianhua, et al.
(författare)
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Highly stretchable organic electrochemical transistors with strain-resistant performance
- 2022
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Ingår i: Nature Materials. - : NATURE PORTFOLIO. - 1476-1122 .- 1476-4660. ; 21, s. 564-571
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Tidskriftsartikel (refereegranskat)abstract
- Realizing fully stretchable electronic materials is central to advancing new types of mechanically agile and skin-integrable optoelectronic device technologies. Here we demonstrate a materials design concept combining an organic semiconductor film with a honeycomb porous structure with biaxially prestretched platform that enables high-performance organic electrochemical transistors with a charge transport stability over 30-140% tensional strain, limited only by metal contact fatigue. The prestretched honeycomb semiconductor channel of donor-acceptor polymer poly(2,5-bis(2-octyldodecyl)-3,6-di(thiophen-2-yl)-2,5-diketo-pyrrolopyrrole-alt-2,5-bis(3-triethyleneglycoloxy-thiophen-2-yl) exhibits high ion uptake and completely stable electrochemical and mechanical properties over 1,500 redox cycles with 10(4) stretching cycles under 30% strain. Invariant electrocardiogram recording cycles and synapse responses under varying strains, along with mechanical finite element analysis, underscore that the present stretchable organic electrochemical transistor design strategy is suitable for diverse applications requiring stable signal output under deformation with low power dissipation and mechanical robustness. Highly stretchable organic electrochemical transistors with stable charge transport under severe tensional strains are demonstrated using a honeycomb semiconducting polymer morphology, thereby enabling controllable signal output for diverse stretchable bioelectronic applications.
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| 3. |
- Eckstein, Brian J., et al.
(författare)
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Naphthalene Bis(4,8-diamino-1,5-dicarboxyl)amide Building Block for Semiconducting Polymers
- 2017
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Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126. ; 139:41, s. 14356-14359
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Tidskriftsartikel (refereegranskat)abstract
- We report a new naphthalene bis(4,8-diamino-1,5-dicarboxyl)amide (NBA) building block for polymeric semiconductors. Computational modeling suggests that regio-connectivity at the 2,6- or 3,7-NBA positions strongly modulates polymer backbone torsion and, therefore, intramolecular pi-conjugation and aggregation. Optical, electrochemical, and X-ray diffraction characterization of 3,7- and 2,6-dithienyl-substituted NBA molecules and, corresponding isomeric NBA, bithiophene copolymers P1 and P2, respectively, reveals the key role of regio-connectivity. Charge transport measurements demonstrate that while the twisted 3,7-NDA-based P1 is a poor semiconductor, the planar 2,6-functionalized NBA polymers (P2-P4) exhibit ambipolarity, with mu(e) and mu(h) of up to 0.39 and 0.32 cm(2)/(V.s), respectively.
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| 4. |
- Eckstein, Brian J., et al.
(författare)
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Processable High Electron Mobility pi-Copolymers via Mesoscale Backbone Conformational Ordering
- 2021
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 31:15
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis and experimental/theoretical characterization of a new series of electron-transporting copolymers based on the naphthalene bis(4,8-diamino-1,5-dicarboxyl)amide (NBA) building block are reported. Comonomers are designed to test the emergent effects of manipulating backbone torsional characteristics, and density functional theory (DFT) analysis reveals the key role of backbone conformation in optimizing electronic delocalization and transport. The NBA copolymer conformational and electronic properties are characterized using a broad array of molecular/macromolecular, thermal, optical, electrochemical, and charge transport techniques. All NBA copolymers exhibit strongly aggregated morphologies with significant nanoscale order. Copolymer charge transport properties are investigated in thin-film transistors and exhibit excellent electron mobilities ranging from 0.4 to 4.5 cm(2) V-1 s(-1). Importantly, the electron transport efficiency correlates with the film mesoscale order, which emerges from comonomer-dependent backbone planarity and extension. These results illuminate the key NBA building block structure-morphology-bulk property design relationships essential for processable, electronics-applicable high-performance polymeric semiconductors.
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| 5. |
- Erdmann, Tim, et al.
(författare)
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Naphthalenediimide Polymers with Finely Tuned In-Chain pi-Conjugation: Electronic Structure, Film Microstructure, and Charge Transport Properties
- 2016
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Ingår i: ADVANCED MATERIALS. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 28:41, s. 9169-
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Tidskriftsartikel (refereegranskat)abstract
- Naphthalenediimide-based random copolymers (PNDI-TVTx) with different p-conjugated dithienylvinylene (TVT) versus p-nonconjugated dithienylethane (TET) unit ratios (x = 100 -amp;gt; 0%) are investigated. The PNDI-TVTx-transistor electron/hole mobilities are affected differently, a result rationalized by molecular orbital topologies and energies, with hole mobility vanishing but electron mobility decreasing only by approximate to 2.5 times when going from x = 100% to 40%.
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| 6. |
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| 7. |
- Fabiano, Simone, et al.
(författare)
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Stretchable helix-structured fibre electronics
- 2021
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Ingår i: NATURE ELECTRONICS. - : NATURE PORTFOLIO. - 2520-1131. ; 4, s. 864-865
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Printed thin-film transistors and circuits fabricated on plastic strips can be wrapped around fibres to create stretchable electronics.
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| 8. |
- Guo, Han, et al.
(författare)
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Transition metal-catalysed molecular n-doping of organic semiconductors
- 2021
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Ingår i: Nature. - London, United Kingdom : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 599:7883, s. 67-73
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Tidskriftsartikel (refereegranskat)abstract
- Electron doping of organic semiconductors is typically inefficient, but here a precursor molecular dopant is used to deliver higher n-doping efficiency in a much shorter doping time. Chemical doping is a key process for investigating charge transport in organic semiconductors and improving certain (opto)electronic devices(1-9). N(electron)-doping is fundamentally more challenging than p(hole)-doping and typically achieves a very low doping efficiency (eta) of less than 10%(1,10). An efficient molecular n-dopant should simultaneously exhibit a high reducing power and air stability for broad applicability(1,5,6,9,11), which is very challenging. Here we show a general concept of catalysed n-doping of organic semiconductors using air-stable precursor-type molecular dopants. Incorporation of a transition metal (for example, Pt, Au, Pd) as vapour-deposited nanoparticles or solution-processable organometallic complexes (for example, Pd-2(dba)(3)) catalyses the reaction, as assessed by experimental and theoretical evidence, enabling greatly increased eta in a much shorter doping time and high electrical conductivities (above 100 S cm(-1); ref. (12)). This methodology has technological implications for realizing improved semiconductor devices and offers a broad exploration space of ternary systems comprising catalysts, molecular dopants and semiconductors, thus opening new opportunities in n-doping research and applications(12, 13).
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| 9. |
- He, Guang S., et al.
(författare)
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Twisted pi-System Chromophores for All-Optical Switching
- 2011
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 133:17, s. 6675-6680
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Tidskriftsartikel (refereegranskat)abstract
- Molecular chromophores with twisted pi-electron systems have been shown to possess unprecedented values of the quadratic hyperpolarizability, beta, with very large real parts and much smaller imaginary parts. We report here an experimental and theoretical study which shows that these twisted chromophores also possess very large values of the real part of the cubic hyperpolarizability, gamma, which is responsible for nonlinear refraction. Thus, for the two-ring twisted chromophore TMC-2 at 775 nm, relatively close to one-photon resonance, n(2) extrapolated to neat substance is large and positive (1.87 x 10(-13) cm(2)/W), leading to self-focusing. Furthermore, the third-order response includes a remarkably low two-photon absorption coefficient, which means minimal nonlinear optical losses: the T factor, alpha(2)lambda/n(2), is 0.308. These characteristics are attributed to closely spaced singlet biradical and zwitterionic states and offer promise for applications in all-optical switching.
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| 10. |
- Kim, Jaehyun, et al.
(författare)
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Monolithically integrated high-density vertical organic electrochemical transistor arrays and complementary circuits
- 2024
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Ingår i: NATURE ELECTRONICS. - : NATURE PORTFOLIO. - 2520-1131.
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Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors (OECTs) can be used to create biosensors, wearable devices and neuromorphic systems. However, restrictions in the micro- and nanopatterning of organic semiconductors, as well as topological irregularities, often limit their use in monolithically integrated circuits. Here we show that the micropatterning of organic semiconductors by electron-beam exposure can be used to create high-density (up to around 7.2 million OECTs per cm2) and mechanically flexible vertical OECT arrays and circuits. The energetic electrons convert the semiconductor exposed area to an electronic insulator while retaining ionic conductivity and topological continuity with the redox-active unexposed areas essential for monolithic integration. The resulting p- and n-type vertical OECT active-matrix arrays exhibit transconductances of 0.08-1.7 S, transient times of less than 100 mu s and stable switching properties of more than 100,000 cycles. We also fabricate vertically stacked complementary logic circuits, including NOT, NAND and NOR gates. Micropatterning of organic semiconductors by electron-beam exposure can be used to create vertical organic electrochemical transistor arrays and complementary logic circuits with densities of up to 7.2 million transistors per cm2.
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