Conjugated polymer films are promising in wearable X-ray detection. However, achieving optimal film microstructure possessing good electrical and detection performance under large deformation via ...scalable printing remains challenging. Herein, we report bar-coated high-performance stretchable films based on a conjugated polymer P(TDPP-Se) and elastomer SEBS blend by optimizing the solution-processing conditions. The moderate preaggregation in solution and prolonged growth dynamics from a solvent mixture with limited dissolving capacity is critical to forming aligned P(TDPP-Se) chains/crystalline nanofibers in the SEBS phase with enhanced π–π stacking for charge transport and stress dissipation. The film shows a large elongation at break of >400% and high mobilities of 5.29 cm2 V–1 s–1 at 0% strain and 1.66 cm2 V–1 s–1 over 500 stretch–release cycles at 50% strain, enabling good X-ray imaging with a high sensitivity of 1501.52 μC Gyair –1 cm–2. Our work provides a morphology control strategy toward high-performance conjugated polymer film-based stretchable electronics.
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IJS, KILJ, NUK, PNG, UL, UM
A wide range of nanophotonic applications rely on polarization‐dependent plasmonic resonances, which usually requires metallic nanostructures that have anisotropic shape. This work demonstrates ...polarization‐dependent plasmonic resonances instead by breaking symmetry via material permittivity. The study shows that molecular alignment of a conducting polymer can lead to a material with polarization‐dependent plasma frequency and corresponding in‐plane hyperbolic permittivity region. This result is not expected based only on anisotropic charge mobility but implies that also the effective mass of the charge carriers becomes anisotropic upon polymer alignment. This unique feature is used to demonstrate circularly symmetric nanoantennas that provide different plasmonic resonances parallel and perpendicular to the alignment direction. The nanoantennas are further tuneable via the redox state of the polymer. Importantly, polymer alignment could blueshift the plasma wavelength and resonances by several hundreds of nanometers, forming a novel approach toward reaching the ultimate goal of redox‐tunable conducting polymer nanoantennas for visible light.
Traditional anisotropic nanoantennas have asymmetric shape. In this work, symmetry is instead broken by straining of a conducting polymer, leading to an in‐plane anisotropic plasma frequency. This enables circularly symmetric nanoantennas with polarization‐dependent localized surface plasmon resonances. The polarization dependence is consistent with inverse changes of the effective mass and mobility of thecharge carriers along different in‐plane directions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A grand challenge in materials science is to identify the impact of molecular composition and structure across a range of length scales on macroscopic properties. We demonstrate a unified ...experimental-theoretical framework that coordinates experimental measurements of mesoscale structure with molecular-level physical modeling to bridge multiple scales of physical behavior. Here we apply this framework to understand charge transport in a semiconducting polymer. Spatially-resolved nanodiffraction in a transmission electron microscope is combined with a self-consistent framework of the polymer chain statistics to yield a detailed picture of the polymer microstructure ranging from the molecular to device relevant scale. Using these data as inputs for charge transport calculations, the combined multiscale approach highlights the underrepresented role of defects in existing transport models. Short-range transport is shown to be more chaotic than is often pictured, with the drift velocity accounting for a small portion of overall charge motion. Local transport is sensitive to the alignment and geometry of polymer chains. At longer length scales, large domains and gradual grain boundaries funnel charges preferentially to certain regions, creating inhomogeneous charge distributions. While alignment generally improves mobility, these funneling effects negatively impact mobility. The microstructure is modified in silico to explore possible design rules, showing chain stiffness and alignment to be beneficial while local homogeneity has no positive effect. This combined approach creates a flexible and extensible pipeline for analyzing multiscale functional properties and a general strategy for extending the accesible length scales of experimental and theoretical probes by harnessing their combined strengths.
A model reduction scheme for polymer semiconductors is presented that can be utilized to compute intra‐chain charge‐carrier mobility from the monomer sequence. The reduced model can be used in ...conjunction with any quantum dynamics approach, but it is explored here assuming that transport takes place through incoherent hopping events between states of different degrees of delocalization. The procedure is illustrated by considering 28 realistic polymers for which a quantitative correlation is established between charge localization characteristics and charge mobility. The data set helps in establishing plausible ranges for all the microscopic parameters of the model and it can therefore be used to determine the maximum plausible improvement in mobility. The reduced model is also used to provide some insight on the observation that the highest mobility polymers do not have very broad valence bands: there is indeed a range of the inter‐monomer coupling for which this parameter has little effect on the mobility.
An effective model reduction scheme for polymer semiconductors is developed to rapidly compute intra‐chain hole mobility from monomer sequence within choices of quantum dynamics method. The procedure is illustrated considering 28 realistic polymers, and the maximum plausible improvement in polymer mobility within realistic range of microscopic parameters as well as correlation between charge localization characteristics and mobility are established.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Here, a new methodology for analyzing the charge‐density dependence of carrier mobility in organic semiconductors, applicable to the low‐charge‐density regime (1014–1017 cm−3) corresponding to the ...operation conditions of many organic optoelectronic devices, is reported. For the P3HT/PCBM blend photovoltaic devices studied herein, the hole mobility µ is found to depend on charge density n according to a power law µ(n) ∝ nδ, where δ = 0.35. This dependence is shown to be consistent with an energetic disorder model based upon an exponential tail of localized intra‐band states.
The charge‐density dependence of the carrier mobility of P3HT/PCBM solar cells is examined using charge‐extraction measurements combined with short‐circuit photocurrent data. The current increases sub‐linearly with charge density consistent with a charge density dependent carrier mobility μ(n). This charge density dependence is the same as determined for the bimolecular recombination coefficient k(n). This agrees with a multiple trapping model in which the carrier mobility and bimolecular recombination coefficient are both charge density dependent μ(n) ∝ k(n).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Semiconductors are widely used in electron devices. With the development of wearable soft-electron devices, conventional inorganic semiconductors are unable to meet the demand because of their high ...rigidity and high cost. Thus, scientists construct organic semiconductors with high charge mobility, low cost, eco-friendly, stretchable, etc. Due to the excellent performance of stretchable organic semiconductors, they can be widely used as wearable soft-electron devices, such as stretchable organic field-effect transistors (OFETs), organic solar cells (OSCs), etc. Contains flexible display devices and flexible power sources, which are of great interest for applications of future electron devices. However, there are still some challenges that need to be solved. Commonly, enhancing the stretchability may cause the degradation of charge mobility, because of the destruction of the conjugated system. Currently, scientists find that hydrogen bonding can enhance the stretchability of organic semiconductors with high charge mobility. Thus in this review, based on the structure and design strategies of hydrogen bonding, various hydrogen bonding induced stretchable organic semiconductors are introduced. In addition, the applications of the hydrogen bonding induced stretchable organic semiconductors are reviewed. Finally, the stretchable organic semiconductors design concept and potential evolution trends are discussed. The final goal is to outline a theoretical scaffold for the design of high-performance wearable soft-electron devices, which can also further advance the development of stretchable organic semiconductors for applications.
Electrophoresis (EP) of droplets is an intriguing phenomenon that has applications in biological systems, separation strategies, and reactor engineering. Droplet EP is significantly different from ...the classic particle EP because of droplet characteristics such as a mobile surface charge and the nonrigidity of the interface. Also, the liquid–liquid system, where there is an interplay between the hydrodynamic and electrokinetic forces in both phases, adds to the complexity of electrophoretic motion. Due to the vast amount of potential applications of droplet EP, a mechanistic understanding of the droplet motion in the presence of an external electric field is crucial. This review provides a background on the mechanism of droplet EP and summarizes the intrinsic interplay between the different relevant forces in these systems. The review also describes the key differences between droplet EP and particle EP, and the impact of these differences on droplet mobility. Additionally, we schematically summarize the effects of key parameters on droplet EP mobility, such as electric double layer polarization, the development of internal flow inside a droplet and boundary effects.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
•α-6T as an electron donor is firstly introduced to fabricate a low-cost TPSC.•Obvious improvement of PCE with an increase of JSC and FF is achieved.•Performance improvement is mainly due to the FRET ...and enhanced charge mobility.•α-6T decreases the resistance and provide more pathways for charge transportation.•α-6T can also modulate the morphology of the active layer.
In this study, the enhanced performance of a conventional bulk heterojunction (BHJ) system based on poly({4,8-bis(2-ethylhexyl)oxybenzo1,2-b:4,5-b′dithiophene-2,6-diyl}{3-fluoro-2-(2-ethylhexyl)carbonylthieno3,4-bthiophenediyl}) (PTB7):6,6-phenyl C71-butyric acid methyl ester (PC71BM) is realized by adding a high charge mobility and low-cost small-molecular material of alpha-hexathienyl (α-6T) as an electron donor. Both the short circuit current (JSC) and fill factor (FF) are facilitated by adding 2 wt% α-6T to form a ternary system, resulting in a 22.2% improvement of power conversion efficiency (PCE) compared with the control binary device. The state-of-art BHJ layer was characterized by UV–Vis absorption, steady-state photoluminescence, space-charge-limited current, atomic force microscopy, and impedance spectra, and the enhanced device performance is mainly attributed to the Förster resonance energy transfer effect from α-6T to PTB7 and the increased charge mobility. The result also showed that the blend morphology can be modulated by the introduction of α-6T electron donor. Moreover, the incorporation of α-6T can contribute to the formation of more potential pathways for charge transportation in the active layer, and decrease the resistance of device.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Organic semiconductors are the focus of numerous studies; they are used in electronic devices. Modern research involves the production of neuromorphic organic materials, including those based on ...liquid crystal materials. The purpose of this work involves the theoretical modeling of molecules (the "core with branches" type) to construct a discotic mesophase capable of performing the functions of a neuromorphic material. For this purpose, the conductivity of crystal porphine, which can act as the nucleus of a molecule of the "core with branches" type, was investigated. The Marcus theory charge mobility values for the hole and electron were 0.148 and 0.088 cm
/V·s, respectively (the MOO method for calculating transfer integrals), and 0.561 and 0.160 cm
/V·s (DIPRO method). Based on TD-HF (HF-3c level of theory) calculations, possible structures of molecules for the formation of a discotic mesophase are proposed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We have investigated the electronic structures and carrier mobility of two dimensional (2D) metal coordination polyporphyrin (PP) sheets using density functional theory combined with Boltzmann ...transport method with relaxation time approximation. Two families of metal coordination atoms are studied: 1) 3d-transition metals (TM) Fe and Co; and 2) nonferrous metals (NM) Li and Zn. It is shown that 2H-PP, 2Li-PP and Zn-PP are direct gap semiconductors, while Fe-PP and Co-PP are spin-splitting and behave like half-metallic. Moreover, the charge mobilities have been carried out under periodic boundary conditions for infinite 2D PP systems, and found that the electron mobility is higher than that of the hole's, which indicating the n-type semiconducting characteristic. Furthermore, we also found the hole mobility in all systems show anisotropy in-plane.
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•Charge mobility and half-metallicity in two dimensional metal coordination PP sheets.•All 2D metal coordination PP sheets show n-type semiconducting.•The hole mobility in all systems show anisotropy in-plane.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
