Articles de revues : « Semiconducting Polymer Molecules »

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Park, Keon Joo, Chae Won Kim, Min Jae Sung, Jiyoul Lee et Young Tea Chun. « Semiconducting Polymer Nanowires with Highly Aligned Molecules for Polymer Field Effect Transistors ». Electronics 11, n^o 4 (18 février 2022) : 648. http://dx.doi.org/10.3390/electronics11040648.

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Conjugated polymers have emerged as promising materials for next-generation electronics. However, in spite of having several advantages, such as a low cost, large area processability and flexibility, polymer-based electronics have their own limitations concerning low electrical performance. To achieve high-performance polymer electronic devices, various strategies have been suggested, including aligning polymer backbones in the desired orientation. In the present paper, we report a simple patterning technique using a polydimethylsiloxane (PDMS) mold that can fabricate highly aligned nanowires of a diketopyrrolopyrrole (DPP)-based donor–acceptor-type copolymer (poly (diketopyrrolopyrrole-alt-thieno [3,2-b] thiophene), DPP-DTT) for high-performance field effect transistors. The morphology of the patterns was controlled by changing the concentration of the DPP-based copolymer solution (1, 3, 5 mg mL−1). The molecular alignment properties of three different patterns were observed with a polarized optical microscope, polarized UV-vis spectroscopy and an X-ray diffractometer. DPP-DTT nanowires made with 1 mg mL−1 solution are highly aligned and the polymer field-effect transistors based on nanowires exhibit more than a five times higher charge carrier mobility as compared to spin-coated film-based devices.

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Zhang, Yue, Fangmao Ye, Wei Sun, Jiangbo Yu, I.-Che Wu, Yu Rong, Yong Zhang et Daniel T. Chiu. « Light-induced crosslinkable semiconducting polymer dots ». Chemical Science 6, n^o 3 (2015) : 2102–9. http://dx.doi.org/10.1039/c4sc03959a.

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Salaneck, W. R., et M. Fahlman. « Hybrid interfaces of conjugate polymers : Band edge alignment studied by ultraviolet photoelectron spectroscopy ». Journal of Materials Research 19, n^o 7 (juillet 2004) : 1917–23. http://dx.doi.org/10.1557/jmr.2004.0262.

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The control of hybrid interfaces in polymer-based electronic devices may be enabling in many applications. The engineering of hybrid interface involves (requires) an understanding of the electronic structure of materials—one organic and one inorganic—that form the two halves of hybrid interfaces, as well as the electronic and chemical consequences of the coupling of the two. Although much literature exists describing the interfaces between vapor-deposited organic molecules and model molecules for polymers on the surfaces of clean metals in ultrahigh vacuum, few studies have been reported on spin-coated, semiconducting polymer films on realistic substrates. Spin coating in an inert atmosphere (or even air) is a central part of the process of the fabrication of polymer-based light-emitting devices and other modern polymer-based electronic components. Here, work on the electronic structure of semiconducting (conjugated) polymer films spin-coated onto selected inorganic substrates, carried out using ultraviolet photoelectron spectroscopy, is reviewed and summarized to generate a generalized picture of the hybrid interfaces formed under realistic device fabrication conditions.

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Machatschek, Rainhard, Patrick Ortmann, Renate Reiter, Stefan Mecking et Günter Reiter. « Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate ». Beilstein Journal of Nanotechnology 7 (2 juin 2016) : 784–98. http://dx.doi.org/10.3762/bjnano.7.70.

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We have investigated the potential of polymers containing precisely spaced side-branches for thin film applications, particularly in the context of organic electronics. Upon crystallization, the side-branches were excluded from the crystalline core of a lamellar crystal. Thus, the surfaces of these crystals were covered by side-branches. By using carboxyl groups as side-branches, which allow for chemical reactions, we could functionalize the crystal with semiconducting molecules. Here, we compare properties of crystals differing in size: small nanocrystals and large single crystals. By assembling nanocrystals on a Langmuir trough, large areas could be covered by monolayers consisting of randomly arranged nanocrystals. Alternatively, we used a method based on local supersaturation to grow large area single crystals of the precisely side-branched polymer from solution. Attachment of the semiconducting molecules to the lamellar surface of large single crystals was possible, however, only after an appropriate annealing procedure. As a function of the duration of the grafting process, the morphology of the resulting layer of semiconducting molecules changed from patchy to compact.

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Kweon, O. Young, Moo Yeol Lee, Teahoon Park, Hanbit Jang, Ayoung Jeong, Moon-Kwang Um et Joon Hak Oh. « Highly flexible chemical sensors based on polymer nanofiber field-effect transistors ». Journal of Materials Chemistry C 7, n^o 6 (2019) : 1525–31. http://dx.doi.org/10.1039/c8tc06051g.

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Garnier, Francis, Fayçal Kouki, Rhiad Hajlaoui et Gilles Horowitz. « Tunneling at Organic/Metal Interfaces in Oligomer-Based Thin-Film Transistors ». MRS Bulletin 22, n^o 6 (juin 1997) : 52–56. http://dx.doi.org/10.1557/s0883769400033637.

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Organic semiconductors have been studied since the early 1950s, and the large amount of work devoted to them has allowed a better understanding of their charge-transport properties. However owing to their very poor semiconducting characteristics, they were merely considered as exotic materials with little potential interest for applications until the late 1980s, when two significant steps simultaneously appeared in the literature. Richard Friend's group showed that light-emitting diodes could be made from a conjugated semiconducting polymer, and our laboratory showed that efficient field-effect transistors (FETs) could be realized from short-conjugated oligomers. These two results launched intensive research on these two types of organic-based devices, and the extensive work accomplished since has largely confirmed the technological pertinence of organic semiconductors, showing the promise for applications in flexible and large-area electronics. Two categories of organic semiconductors are actually under development: (1) conjugated polymer-based ones whose amorphous state is favorable to strong luminescence and (2) conjugated oligomer-based ones, in which charge-transport efficiency is directly related to the long-range packing of molecules in the semiconducting film. In fact conjugated oligomers can be said to be forming molecular polycrystals whose electrical properties are essentially controlled by molecular order. Thus performance of sexithiophene-based FETs has been improved by a factor of nearly 50 by controlling the molecular ordering in the evaporated film, from a disordered three-dimensional structure to a well-ordered two-dimensional organization where all the molecules stack along a packing axis nearly parallel to the substrate surface.

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Kang, Minji, Jun-Seok Yeo, Won-Tae Park, Nam-Koo Kim, Dae-Hee Lim, Hansu Hwang, Kang-Jun Baeg, Yong-Young Noh et Dong-Yu Kim. « Favorable Molecular Orientation Enhancement in Semiconducting Polymer Assisted by Conjugated Organic Small Molecules ». Advanced Functional Materials 26, n^o 46 (18 octobre 2016) : 8527–36. http://dx.doi.org/10.1002/adfm.201603617.

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Barbosa, Hélder M. C., et Marta M. D. Ramos. « Computer Simulation of Hole Distribution in Polymeric Materials ». Materials Science Forum 587-588 (juin 2008) : 711–15. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.711.

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Polymers have been known for their flexibility and easy processing into coatings and films, which made them suitable to be applied in a variety of areas and in particular the growing area of organic electronics. The electronic properties of semiconducting polymers made them a serious rival in areas where until now inorganic materials were the most used, such as light emitting diodes or solar cells. Typical polymers can be seen as a network of molecular strands of varied lengths and orientations, with a random distribution of physical and chemical defects which makes them an anisotropic material. To further increase their performance, a better understanding of all aspects related to charge transport and space charge distribution in polymeric materials is required. The process associated with charge transport depends on the properties of the polymer molecules as well as connectivity and texture, and so we adopt a mesoscopic approach to build polymer structures. Changing the potential barrier for charge injection we can introduce holes in the polymer network and, by using a generalised Monte-Carlo method, we can simulate the transport of the injected charge through the polymer layer caused by imposing a voltage between two planar electrodes. Our results show that the way that holes distribute within polymer layer and charge localization in these materials is quite different from the inorganic ones.

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Kietzke, Thomas. « Recent Advances in Organic Solar Cells ». Advances in OptoElectronics 2007 (23 mars 2007) : 1–15. http://dx.doi.org/10.1155/2007/40285.

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Solar cells based on organic semiconductors have attracted much attention. The thickness of the active layer of organic solar cells is typically only 100 nm thin, which is about 1000 times thinner than for crystalline silicon solar cells and still 10 times thinner than for current inorganic thin film cells. The low material consumption per area and the easy processing of organic semiconductors offer a huge potential for low cost large area solar cells. However, to compete with inorganic solar cells the efficiency of organic solar cells has to be improved by a factor of 2-3. Several organic semiconducting materials have been investigated so far, but the optimum material still has to be designed. Similar as for organic light emitting devices (OLED) small molecules are competing with polymers to become the material of choice. After a general introduction into the device structures and operational principles of organic solar cells the three different basic types (all polymer based, all small molecules based and small molecules mixed with polymers) are described in detail in this review. For each kind the current state of research is described and the best of class reported efficiencies are listed.

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Lau, W. M., Z. Zheng, Y. H. Wang, Y. Luo, L. Xi, K. W. Wong et K. Y. Wong. « Cross-linking organic semiconducting molecules by preferential C-H cleavage via “chemistry with a tiny hammer” ». Canadian Journal of Chemistry 85, n^o 10 (1 octobre 2007) : 859–65. http://dx.doi.org/10.1139/v07-101.

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In the context of collision-induced dissociation in chemistry and kinematics in physics, we have determined that a beam of hyperthermal protons can be used as tiny hammers to preferentially break the C-H bonds of hydrocarbon precursor molecules adsorbed on a conductive substrate with little damage to other chemical bonds. The activated molecules are thereby converted to a cross-linked molecular network, with its chemical properties tailored by the preservation of the chemical functional groups of the precursors and with its physical properties tuned by the degree of cross-linking. This chemistry with a tiny hammer process is adopted to induce inter-chain cross-linking of the semiconducting molecular chains in poly (3,4-ethylenedioxythiophene) molecular films and to raise the electrical conductivity and stability of the molecular films. The results exemplify the unusual reaction design of this process as well as its application in electronic and optoelectronic device fabrication. The application is particularly attractive because the process does not require any chemical additives or catalysts other than a beam of protons, and it needs no thermal budget.Key words: organic semiconductor, polymeric semiconductor, cross-linking, polymer, collision, dissociative collision, molecular electronics, device fabrication.

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Velessiotis, D., V. Ioannou-Sougleridis, G. Chaidogiannos et N. Glezos. « Compound polymeric materials in molecular nanodevices : electrical behavior of zero-dimension semiconducting inorganic molecules embedded in a polymer substrate ». Journal of Physics : Conference Series 10 (1 janvier 2005) : 93–96. http://dx.doi.org/10.1088/1742-6596/10/1/023.

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Mehta, A., P. Kumar, M. D. Dadmun, J. Zheng, R. M. Dickson, T. Thundat, B. G. Sumpter et M. D. Barnes. « Oriented Nanostructures from Single Molecules of a Semiconducting Polymer : Polarization Evidence for Highly Aligned Intramolecular Geometries ». Nano Letters 3, n^o 5 (mai 2003) : 603–7. http://dx.doi.org/10.1021/nl0340733.

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Mizoguchi, Rei, Naoki Akiyama, Sayaka Hiruta, Masaki Kobayashi, Masahiro Kashiwazaki et Norio Onojima. « Influence of ambient condition on off-state current of polymer-blend transistors based on 6,13-bis(triisopropylsilylethynyl) pentacene with deposition of molybdenum trioxide ». Japanese Journal of Applied Physics 61, SE (5 avril 2022) : SE1015. http://dx.doi.org/10.35848/1347-4065/ac5fba.

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Abstract We have fabricated blend films comprising 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) as a semiconducting small molecule and poly(methyl methacrylate) (PMMA) as an insulating polymer by electrostatic spray deposition (ESD). A thin film (5 nm) of molybdenum trioxide (MoO3) was evaporated on the entirety of the active layer surface. Then, we found that the off-state current in OFETs using the TIPS pentacene/PMMA blend films apparently increased. This result probably indicates the formation of a conductive surface channel due to the MoO3 deposition. In this study, we performed morphological and chemical analyzes. In consequence, we found that only Mo atoms (not together with O atoms) penetrated into TIPS pentacene and oxidation of Mo to MoO x could enhance charge transfer between neighboring TIPS pentacene molecules. Furthermore, this study demonstrated that the off-state current could be modulated by changing the ambient condition, such as relative humidity.

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Al-Azzawi, Ahmed G. S., Shujahadeen B. Aziz, Elham M. A. Dannoun, Ahmed Iraqi, Muaffaq M. Nofal, Ary R. Murad et Ahang M. Hussein. « A Mini Review on the Development of Conjugated Polymers : Steps towards the Commercialization of Organic Solar Cells ». Polymers 15, n^o 1 (29 décembre 2022) : 164. http://dx.doi.org/10.3390/polym15010164.

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This review article covers the synthesis and design of conjugated polymers for carefully adjusting energy levels and energy band gap (EBG) to achieve the desired photovoltaic performance. The formation of bonds and the delocalization of electrons over conjugated chains are both explained by the molecular orbital theory (MOT). The intrinsic characteristics that classify conjugated polymers as semiconducting materials come from the EBG of organic molecules. A quinoid mesomeric structure (D-A D+ = A−) forms across the major backbones of the polymer as a result of alternating donor–acceptor segments contributing to the pull–push driving force between neighboring units, resulting in a smaller optical EBG. Furthermore, one of the most crucial factors in achieving excellent performance of the polymer is improving the morphology of the active layer. In order to improve exciton diffusion, dissociation, and charge transport, the nanoscale morphology ensures nanometer phase separation between donor and acceptor components in the active layer. It was demonstrated that because of the exciton’s short lifetime, only small diffusion distances (10–20 nm) are needed for all photo-generated excitons to reach the interfacial region where they can separate into free charge carriers. There is a comprehensive explanation of the architecture of organic solar cells using single layer, bilayer, and bulk heterojunction (BHJ) devices. The short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) all have a significant impact on the performance of organic solar cells (OSCs). Since the BHJ concept was first proposed, significant advancement and quick configuration development of these devices have been accomplished. Due to their ability to combine great optical and electronic properties with strong thermal and chemical stability, conjugated polymers are unique semiconducting materials that are used in a wide range of applications. According to the fundamental operating theories of OSCs, unlike inorganic semiconductors such as silicon solar cells, organic photovoltaic devices are unable to produce free carrier charges (holes and electrons). To overcome the Coulombic attraction and separate the excitons into free charges in the interfacial region, organic semiconductors require an additional thermodynamic driving force. From the molecular engineering of conjugated polymers, it was discovered that the most crucial obstacles to achieving the most desirable properties are the design and synthesis of conjugated polymers toward optimal p-type materials. Along with plastic solar cells (PSCs), these materials have extended to a number of different applications such as light-emitting diodes (LEDs) and field-effect transistors (FETs). Additionally, the topics of fluorene and carbazole as donor units in conjugated polymers are covered. The Stille, Suzuki, and Sonogashira coupling reactions widely used to synthesize alternating D–A copolymers are also presented. Moreover, conjugated polymers based on anthracene that can be used in solar cells are covered.

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Afraj, Shakil N., Guan‐Yu He, Chih‐Yu Lin, Arulmozhi Velusamy, Chu‐Yun Huang, Po‐Shen Lin, Sureshraju Vegiraju et al. « Solution‐Processable Multifused Thiophene Small Molecules and Conjugated Polymer Semiconducting Blend for Organic Field Effect Transistor Application ». Advanced Materials Technologies 6, n^o 3 (10 février 2021) : 2001028. http://dx.doi.org/10.1002/admt.202001028.

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Riahin, Connor, Kushani Mendis, Brandon Busick, Marcin Ptaszek, Mengran Yang, Gary Stacey, Amar Parvate et al. « Near Infrared Emitting Semiconductor Polymer Dots for Bioimaging and Sensing ». Sensors 22, n^o 19 (23 septembre 2022) : 7218. http://dx.doi.org/10.3390/s22197218.

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Semiconducting polymer dots (Pdots) are rapidly becoming one of the most studied nanoparticles in fluorescence bioimaging and sensing. Their small size, high brightness, and resistance to photobleaching make them one of the most attractive fluorophores for fluorescence imaging and sensing applications. This paper highlights our recent advances in fluorescence bioimaging and sensing with nanoscale luminescent Pdots, specifically the use of organic dyes as dopant molecules to modify the optical properties of Pdots to enable deep red and near infrared fluorescence bioimaging applications and to impart sensitivity of dye doped Pdots towards selected analytes. Building on our earlier work, we report the formation of secondary antibody-conjugated Pdots and provide Cryo-TEM evidence for their formation. We demonstrate the selective targeting of the antibody-conjugated Pdots to FLAG-tagged FLS2 membrane receptors in genetically engineered plant leaf cells. We also report the formation of a new class of luminescent Pdots with emission wavelengths of around 1000 nm. Finally, we demonstrate the formation and utility of oxygen sensing Pdots in aqueous media.

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Nie, Shisong, Fei Qin, Yanfeng Liu, Chufeng Qiu, Yingzhi Jin, Hongmei Wang, Lichun Liu et al. « High Conductivity, Semiconducting, and Metallic PEDOT:PSS Electrode for All-Plastic Solar Cells ». Molecules 28, n^o 6 (21 mars 2023) : 2836. http://dx.doi.org/10.3390/molecules28062836.

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Plastic electrodes are desirable for the rapid development of flexible organic electronics. In this article, a plastic electrode has been prepared by employing traditional conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and plastic substrate polyethersulfone (PES). The completed electrode (Denote as HC-PEDOT:PSS) treated by 80% concentrated sulfuric acid (H2SO4) possesses a high electrical conductivity of over 2673 S/cm and a high transmittance of over 90% at 550 nm. The high conductivity is attributed to the regular arrangement of PEDOT molecules, which has been proved by the X-ray diffraction characterization. Temperature-dependent conductivity measurement reveals that the HC-PEDOT:PSS possesses both semiconducting and metallic properties. The binding force and effects between the PEDOT and PEI are investigated in detail. All plastic solar cells with a classical device structure of PES/HC-PEDOT:PSS/PEI/P3HT:ICBA/EG-PEDOT:PSS show a PCE of 4.05%. The ITO-free device with a structure of Glass/HC-PEDOT:PSS/Al4083/PM6:Y6/PDINO/Ag delivers an open-circuit voltage (VOC) of 0.81 V, short-circuit current (JSC ) of 23.5 mA/cm2, fill factor (FF) of 0.67 and a moderate power conversion efficiency (PCE) of 12.8%. The above results demonstrate the HC-PEDOT:PSS electrode is a promising candidate for all-plastic solar cells and ITO-free organic solar cells.

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Jahng, Junghoon, Hyuksang Kwon et Eun Lee. « Photo-Induced Force Microscopy by Using Quartz Tuning-Fork Sensor ». Sensors 19, n^o 7 (29 mars 2019) : 1530. http://dx.doi.org/10.3390/s19071530.

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We present the photo-induced force microscopy (PiFM) studies of various nano-materials by implementing a quartz tuning fork (QTF), a self-sensing sensor that does not require complex optics to detect the motion of a force probe and thus helps to compactly configure the nanoscale optical mapping tool. The bimodal atomic force microscopy technique combined with a sideband coupling scheme is exploited for the high-sensitivity imaging of the QTF-PiFM. We measured the photo-induced force images of nano-clusters of Silicon 2,3-naphthalocyanine bis dye and thin graphene film and found that the QTF-PiFM is capable of high-spatial-resolution nano-optical imaging with a good signal-to-noise ratio. Applying the QTF-PiFM to various experimental conditions will open new opportunities for the spectroscopic visualization and substructure characterization of a vast variety of nano-materials from semiconducting devices to polymer thin films to sensitive measurements of single molecules.

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Kohn, Sophia, Daria Wehlage, Irén Juhász Junger et Andrea Ehrmann. « Electrospinning a Dye-Sensitized Solar Cell ». Catalysts 9, n^o 12 (21 novembre 2019) : 975. http://dx.doi.org/10.3390/catal9120975.

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Dye-sensitized solar cells (DSSCs) offer new possibilities to harvest solar energy by using non-toxic inexpensive materials. Since they can generally be produced on flexible substrates, several research groups investigated possibilities to integrate DSSCs in textile fabrics, either by coating full fabrics with the DSSC layer structure or by producing fiber-shaped DSSCs which were afterwards integrated into a textile fabric. Here we show a new approach, electrospinning all solid layers of the DSSC. We report on electrospinning the counter electrode with a graphite catalyst followed by a thin nonconductive barrier layer and preparing the front electrode by electrospinning semiconducting TiO2 from a polymer solution dyed with natural dyes. Both electrodes were coated with a conductive polymer before the system was finally filled with a fluid electrolyte. While the efficiency is lower than for glass-based cells, possible problems such as short-circuits—which often occur in fiber-based DSSCs—did not occur in this proof-of-concept. Since graphite particles did not fully cover the counter electrode in this first study, and the typical bathochromic shift indicating adsorption of dye molecules on the TiO2 layer was not observed, several ways are open to increase the efficiency in forthcoming studies.

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Schopp, Nora, et Viktor V. Brus. « A Review on the Materials Science and Device Physics of Semitransparent Organic Photovoltaics ». Energies 15, n^o 13 (24 juin 2022) : 4639. http://dx.doi.org/10.3390/en15134639.

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In this review, the current state of materials science and the device physics of semitransparent organic solar cells is summarized. Relevant synthetic strategies to narrow the band gap of organic semiconducting molecules are outlined, and recent developments in the polymer donor and near-infrared absorbing acceptor materials are discussed. Next, an overview of transparent electrodes is given, including oxides, multi-stacks, thin metal, and solution processed electrodes, as well as considerations that are unique to ST-OPVs. The remainder of this review focuses on the device engineering of ST-OPVs. The figures of merit and the theoretical limitations of ST-OPVs are covered, as well as strategies to improve the light utilization efficiency. Lastly, the importance of creating an in-depth understanding of the device physics of ST-OPVs is emphasized and the existing works that answer fundamental questions about the inherent changes in the optoelectronic processes in transparent devices are presented in a condensed way. This last part outlines the changes that are unique for devices with increased transparency and the resulting implications, serving as a point of reference for the systematic development of next-generation ST-OPVs.

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Yoneya, Makoto, Satoshi Matsuoka, Jun’ya Tsutsumi et Tatsuo Hasegawa. « Self-assembly of donor–acceptor semiconducting polymers in solution thin films : a molecular dynamics simulation study ». Journal of Materials Chemistry C 5, n^o 37 (2017) : 9602–10. http://dx.doi.org/10.1039/c7tc01014a.

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Wang, Yang, et Tsuyoshi Michinobu. « Rational design strategies for electron-deficient semiconducting polymers in ambipolar/n-channel organic transistors and all-polymer solar cells ». Journal of Materials Chemistry C 6, n^o 39 (2018) : 10390–410. http://dx.doi.org/10.1039/c8tc03967d.

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This review has critically summarized the recent molecular design strategies for the electron-deficient semiconducting polymers. The molecular structural implications related to the ambipolar/n-type device performances of transistors and all-polymer solar cells are discussed.

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Ramanavicius, Simonas, Arunas Jagminas et Arunas Ramanavicius. « Advances in Molecularly Imprinted Polymers Based Affinity Sensors (Review) ». Polymers 13, n^o 6 (22 mars 2021) : 974. http://dx.doi.org/10.3390/polym13060974.

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Recent challenges in biomedical diagnostics show that the development of rapid affinity sensors is very important issue. Therefore, in this review we are aiming to outline the most important directions of affinity sensors where polymer-based semiconducting materials are applied. Progress in formation and development of such materials is overviewed and discussed. Some applicability aspects of conducting polymers in the design of affinity sensors are presented. The main attention is focused on bioanalytical application of conducting polymers such as polypyrrole, polyaniline, polythiophene and poly(3,4-ethylenedioxythiophene) ortho-phenylenediamine. In addition, some other polymers and inorganic materials that are suitable for molecular imprinting technology are also overviewed. Polymerization techniques, which are the most suitable for the development of composite structures suitable for affinity sensors are presented. Analytical signal transduction methods applied in affinity sensors based on polymer-based semiconducting materials are discussed. In this review the most attention is focused on the development and application of molecularly imprinted polymer-based structures, which can replace antibodies, receptors, and many others expensive affinity reagents. The applicability of electrochromic polymers in affinity sensor design is envisaged. Sufficient biocompatibility of some conducting polymers enables to apply them as “stealth coatings” in the future implantable affinity-sensors. Some new perspectives and trends in analytical application of polymer-based semiconducting materials are highlighted.

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Thuau, Damien. « (Invited) Organic Thin Films Transistors : From Mechanical to Biochemical Sensors ». ECS Meeting Abstracts MA2022-02, n^o 35 (9 octobre 2022) : 1287. http://dx.doi.org/10.1149/ma2022-02351287mtgabs.

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Interest in organic electronic materials, and in particular their potential for low-cost fabrication over large areas, led to the development of organic field-effect transistors (OFETs). The potential of OFETs has been demonstrated in a variety of applications, including pixel drivers for displays, bionic skin, wearable electronics and sensitive chemical sensors that can operate in aqueous environments. OFETs use conjugated, semiconducting small molecules and polymers and offer an alternative to inorganic devices for applications in which facile processing on different substrates and tunable electronic properties are required. The flexibility requirement implies either performance stability towards deformation, or conversely, detectable response to the deformation itself. The knowledge of the electromechanical response of organic semiconductors to external stresses is therefore not only interesting from a fundamental point of view, but also necessary for the development of real world applications. To this end, this presentation highlights the importance of the choice of functional materials (organic semiconductors and dielectrics) as well as the relationship structure/properties in transistors based sensors. Organic semiconductors (OSCs) are promising transducer materials when applied in OFETs taking advantage of their electrical properties that highly depend on the morphology of the semiconducting film. The effects of a high-performance p-type organic semiconductor, namely dinaphtho [2,3-b:2,3-f] thieno [3,2–b] thiophene (DNTT) thickness on its piezoresistive sensitivity are presented. A critical thickness corresponding to the appearance of charge carriers percolation paths in the material can tune the gauge factors (GFs) by a factor 10. In addition, single crystal OSC are regarded as promising electroactive materials for strain sensing application. Herein this talk, we will present how strain induces simultaneous mobility changes along all three axes, and that in some cases the response is higher along directions orthogonal to the mechanical deformation. These variations cannot be explained by the modulation of intermolecular distances, but only by a more complex molecular reorganisation, which is particularly enhanced, in terms of response, by p-stacking and herringbone stacking. This microscopic knowledge of the relation between structural and mobility variations is essential for the interpretation of electromechanical measurements for crystalline organic semiconductors, and for the rational design of electronic devices. Alternatively, this talk will highlight how the use of an active gate dielectric layer such as poly(vinylidenefluoride/trifluoroethylene) (P(VDF-TrFE)) piezoelectric polymer can lead to highly efficient electro-mechanical sensitivity. In such case, the sensing mechanism of the electro-mechanical transducer originates from the piezoelectric material itself, which affects the electrical behavior of the transistor as signature of a mechanical event. The second part of this talk will focus on another kind of TFT based sensor, namely the organic electrochemical transistors (OECTs) which have found recently applications in chemical and biological sensing and interfacing and neuromorphic computing. OECT rely on ions that are injected from the electrolyte into polymer-based mixed conductors, thereby changing its doping state and hence its conductivity. While great progress has been achieved, organic mixed conductors frequently experience significant volumetric changes during ion uptake/rejection, i.e., during doping/ de-doping and charging/discharging. Although ion dynamics may be enhanced in expanded networks, these volumetric changes can have undesirable consequences, e.g., negatively affecting hole/electron conduction and severely shortening device lifetime. New materials able to transport ions and electrons/holes and that exhibits low swelling will be presented, expanding the materials-design toolbox for the creation of low-swelling soft mixed conductors with tailored properties and applications in bioelectronics and beyond.

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Kulatunga, Piumi, Nastaran Yousefi et Simon Rondeau-Gagné. « Polyethylene and Semiconducting Polymer Blends for the Fabrication of Organic Field-Effect Transistors : Balancing Charge Transport and Stretchability ». Chemosensors 10, n^o 6 (24 mai 2022) : 201. http://dx.doi.org/10.3390/chemosensors10060201.

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Polyethylene is amongst the most used polymers, finding a plethora of applications in our lives owing to its high impact resistance, non-corrosive nature, light weight, cost effectiveness, and easy processing into various shapes from different sizes. Despite these outstanding features, the commodity polymer has been underexplored in the field of organic electronics. This work focuses on the development of new polymer blends based on a low molecular weight linear polyethylene (LPE) derivative with a high-performance diketopyrrolopyrrole-based semiconducting polymer. Physical blending of the polyethylene with semiconducting polymers was performed at ratios varying from 0 to 75 wt.%, and the resulting blends were carefully characterized to reveal their electronic and solid-state properties. The new polymer blends were also characterized to reveal the influence of polyethylene on the mechanical robustness and stretchability of the semiconducting polymer. Overall, the introduction of LPE was shown to have little to no effect on the solid-state properties of the materials, despite some influence on solid-state morphology through phase separation. Organic field-effect transistors prepared from the new blends showed good device characteristics, even at higher ratios of polyethylene, with an average mobility of 0.151 cm2 V−1 s−1 at a 25 wt.% blend ratio. The addition of polyethylene was shown to have a plasticizing effect on the semiconducting polymers, helping to reduce crack width upon strain and contributing to devices accommodating more strain without suffering from decreased performance. The new blends presented in this work provide a novel platform from which to access more mechanically robust organic electronics and show promising features for the utilization of polyethylene for the solution processing of advanced semiconducting materials toward novel soft electronics and sensors.

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Aivali, Stefania, Konstantinos C. Andrikopoulos et Aikaterini K. Andreopoulou. « Nucleophilic Aromatic Substitution of Pentafluorophenyl-Substituted Quinoline with a Functional Perylene : A Route to the Modification of Semiconducting Polymers ». Polymers 15, n^o 12 (18 juin 2023) : 2721. http://dx.doi.org/10.3390/polym15122721.

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A systematic study of the influence of the chemical substitution pattern of semiconducting polymers carrying side chain perylene diimide (PDI) groups is presented. Semiconducting polymers based on perflurophenyl quinoline (5FQ) were modified via a readily accessible nucleophilic substitution reaction. The perfluorophenyl group was studied as an electron-withdrawing reactive functionality on semiconducting polymers that can undergo fast nucleophilic aromatic substitution. A PDI molecule, functionalized with one phenol group on the bay area, was used for the substitution of the fluorine atom at the para position in 6-vinylphenyl-(2-perfluorophenyl)-4-phenyl quinoline. The final product was polymerized under free radical polymerization providing polymers of 5FQ incorporated with PDI side groups. Alternatively, the post-polymerization modification of the fluorine atoms at the para position of the 5FQ homopolymer with the PhOH-di-EH-PDI was also successfully tested. In this case, the PDI units were partially introduced to the perflurophenyl quinoline moieties of the homopolymer. The para-fluoro aromatic nucleophilic substitution reaction was confirmed and estimated via 1H and 19F NMR spectroscopies. The two different polymer architectures, namely, fully or partially modified with PDI units, were studied in terms of their optical and electrochemical properties, while their morphology was evaluated using TEM analysis, revealing polymers of tailor-made optoelectronic and morphological properties. This work provides a novel molecule-designing method for semiconducting materials of controlled properties.

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Bkkar, Muhammad Ahmad, Roman Olegovich Olekhnovich et Mayya Valerievna Uspenskaya. « Perovskite Nanocomposite Layers Engineering for Efficient and Stable Solar Cells ». Journal of Nano Research 71 (25 janvier 2022) : 71–109. http://dx.doi.org/10.4028/www.scientific.net/jnanor.71.71.

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Recently, perovskite nanocomposites have attracted much ‎attention as active layers due to the relatively high stable efficiency of solar cells based on them. In this ‎paper, we study perovskite nanocomposite layers based on ‎semiconductive/nonconductive molecules or polymers, their deposition methods, properties, and ‎influence on the device performance. We have found that the quality of the ‎perovskite layer (morphology and crystallinity, cross-linked grains, trap states density, as well as ‎conductivity and charge carrier mobility) is strongly affected by various factors ‎related to the additive: such as type (i. e. semiconductive or nonconductive, ‎molecule or polymer), chemical structure (backbone length and ‎molecular weight, functional groups, π system, side chains, donating atoms and basicity), amount,‎ solubility, conductivity, photoactivity, polarity, hydrophobicity, and addition methods. Due to the small amounts added, these additives can lead to slight changes in energy levels, bandgap (Eg), and light absorption ‎properties. Ultimately, using the suitable deposition method and additive at an optimal amount can ‎greatly improve the stability and efficiency of the devices and reduce ‎hysteresis.

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Ramos, Marta M. D., Helena M. G. Correia et Hélder M. C. Barbosa. « Theoretical Study of the Influence of Chemical Defects on the Molecular Properties of Semiconducting Polymers ». Materials Science Forum 636-637 (janvier 2010) : 332–37. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.332.

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Semiconductor polymers are successfully implemented in a broad range of applications such as light emitting diodes, field effect transistors and photovoltaic devices. Most of the achievements reached in the development of these devices were obtained at experimental level, being difficult to identify individually the influence of each factor that limits and controls these devices efficiency. One of the factors that strongly influence the performance of polymer-based devices is the presence of chemical defects in the polymer strands that change their molecular properties. As a result, these polymer strands can work like traps or deep energetic states for charge transport, leading, for instance, to a decrease on charge mobility. At experimental level it is a difficult task to isolate the influence of each type of chemical defects individually on the molecular properties of the polymer strands. It is in this context that theoretical modelling seems to be the most suitable approach to get a deep understanding of the influence of chemical defects on the molecular properties of semiconductor polymers. By performing quantum molecular dynamics calculations we study the influence of chemical defects on the molecular properties of poly(para-phenylenevinylene) (PPV). Our results show clearly a significant difference on the electronic properties of defective polymer strands (e.g. charge carrier localization, ionization potential, electron affinity and electric-field threshold for charge carrier mobility along the polymer backbone) as compared with defect-free strands.

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Salaneck, W. R., et J. L. Brédas. « Conjugated Polymer Surfaces and Interfaces for Light-Emitting Devices ». MRS Bulletin 22, n^o 6 (juin 1997) : 46–51. http://dx.doi.org/10.1557/s0883769400033625.

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Since the discovery of high electrical conductivity in doped polyacetylene in 1977, π-conjugated polymers have emerged as viable semiconducting electronic materials for numerous applications. In the context of polymer electronic devices, one must understand the nature of the polymer surface's electronic structure and the interface with metals. For conjugated polymers, photoelectron spectroscopy—especially in connection with quantum-chemical modeling—provides a maximum amount of both chemical and electronic structural information in one (type of) measurement. Some details of the early stages of interface formation with metals on the surfaces of conjugated polymers and model molecular solids in connection with polymer-based light-emitting devices (LEDs) are outlined. Then a chosen set of issues is summarized in a band structure diagram for a polymer LED, based upon a “clean calcium electrode” on the clean surface of a thin film of poly(p-phenylene vinylene) (PPV). This diagram helps to point out the complexity of the systems involved in polymer LEDs. No such thing as “an ideal metal-on-polymer contact” exists. There is always some chemistry occurring at the interface.

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Pandya, Maharshi, et Raghaw Saran. « Application of Nanoparticals in Medicine ». Journal of ISAS 1, n^o 2 (31 juillet 2022) : 1–21. http://dx.doi.org/10.59143/isas.jisas.1.2/mvsb9110.

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Nanomaterials due to their size (ranging from 0.1-100 nm, at least in one dimension) and higher ratio of surface area to volume display dominant quantum effects causing drastic changes in their chemical reactivity as well as optical, elastic, electrical and magnetic properties. The electrons due to their wave nature move very easily without scattering in nanomaterials and allow their use as biological sensors. Nano wires, semiconducting in nature, act as a versatile optoelectronic component in photodetectors sensitive to polarization and arrays with sub wavelength resolution. The wide applicability of nanomaterials in medicines emerge from the similarity in size of biomolecule moieties of metabolic processes occurring at nano levels. Optical properties of quantum dots allow their use as biomarkers subsequent to coating with a material able to bind selectively with certain biological structures like cancer cells by fluorescent absorption followed by emission of electrons known as functionalised quantum dots. Nanomaterials on combining with biomolecules develop ability to recognize sensitive diagnostic and regulated drug delivery processes with appreciably better performances and may be used as tissue substitutes. The properties produced in organic solvents make them hydrophobic and incompatible to biological molecules. At the same time, they may be converted into water soluble form and made biocompatible through different techniques like ligand exchange, encapsulation, polymer coating (with functional groups attached to the surface) providing reactive site for bio conjugation through different processes keeping limitations of the processes in view. Nanomaterials play prominent role in medicines as obviated by growing global market for them in the field expected to reach to USD 182.3 billion by 2027 at a compounded annual growth rate of 19.9% from 2021

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Pandya, Maharshi, et Raghaw Saran. « Application of Nanoparticles in Medicine ». Journal of ISAS 1, n^o 2 (31 octobre 2022) : 1–21. http://dx.doi.org/10.59143/isas.jisas.1.2.mvsb9110.

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Nanomaterials due to their size (ranging from 0.1-100 nm, at least in one dimension) and higher ratio of surface area to volume display dominant quantum effects causing drastic changes in their chemical reactivity as well as optical, elastic, electrical and magnetic properties. The electrons due to their wave nature move very easily without scattering in nanomaterials and allow their use as biological sensors. Nano wires, semiconducting in nature, act as a versatile optoelectronic component in photodetectors sensitive to polarization and arrays with sub wavelength resolution. The wide applicability of nanomaterials in medicines emerge from the similarity in size of biomolecule moieties of metabolic processes occurring at nano levels. Optical properties of quantum dots allow their use as biomarkers subsequent to coating with a material able to bind selectively with certain biological structures like cancer cells by fluorescent absorption followed by emission of electrons known as functionalised quantum dots. Nanomaterials on combining with biomolecules develop ability to recognize sensitive diagnostic and regulated drug delivery processes with appreciably better performances and may be used as tissue substitutes. The properties produced in organic solvents make them hydrophobic and incompatible to biological molecules. At the same time, they may be converted into water soluble form and made biocompatible through different techniques like ligand exchange, encapsulation, polymer coating (with functional groups attached to the surface) providing reactive site for bio conjugation through different processes keeping limitations of the processes in view. Nanomaterials play prominent role in medicines as obviated by growing global market for them in the field expected to reach to USD 182.3 billion by 2027 at a compounded annual growth rate of 19.9% from 2021.

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Xu, Hangxun. « Conjugated Polymer Nanosheets for Photocatalytic Overall Water Splitting ». ECS Meeting Abstracts MA2018-01, n^o 31 (13 avril 2018) : 1914. http://dx.doi.org/10.1149/ma2018-01/31/1914.

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Photocatalysts based on semiconducting conjugated polymers have shown great potential in solar-driven water splitting. The synthetic conjugated polymers offer great versability to design photocatalyts with suitable electronic structures for photocatalytic reactions. So far much efforts have been devoted to developing semiconducting conjugated polymers for photocatalytic hydrogen evolution. However, conjugated polymers that are able to efficiently split pure water under visible light (>400 nm) via a four-electron pathway have been proved to be challenging. We show that 1,3-diyne-linked conjugated polymer nanosheets obtained by oxidative coupling of terminal alkynes such as 1,3,5-tris-(4-ethynylphenyl)-benzene (TEPB) and 1,3,5-triethynylbenzene (TEB) are possessing suitable band structures for photocatalytic overall water splitting and can act as highly efficient photocatalysts for splitting pure water (pH~7) into stoichiometric amounts of H2 and O2 under visible light irradiation. We also reveal that these conjugated polymers are indeed able to split pure water via first-principles calculations. Using in situ techniques, we could further elucidate the molecular intermediates that are formed during the photocatalytic process, providing strong evidence that the water splitting reaction could occur on the surface of polymer photocatalysts. We believe that our study could provide new insights in design and synthesis of semiconductors that are able to catalyze overall water splitting at neutral pH with sunlight as the only energy input.

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Vohra, Varun, et Takuya Anzai. « Molecular Orientation of Conjugated Polymer Chains in Nanostructures and Thin Films : Review of Processes and Application to Optoelectronics ». Journal of Nanomaterials 2017 (2017) : 1–18. http://dx.doi.org/10.1155/2017/3624750.

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Semiconducting polymers are composed of elongated conjugated polymer backbones and side chains with high solubility and mechanical properties. The combination of these two features results in a high processability and a potential to orient the conjugated backbones in thin films and nanofibers. The thin films and nanofibers are usually composed of highly crystalline (high charge transport) and amorphous parts. Orientation of conjugated polymer can result in enhanced charge transport or optical properties as it induces increased crystallinity or preferential orientation of the crystallites. After summarizing the potential strategies to exploit molecular order in conjugated polymer based optoelectronic devices, we will review some of the fabrication processes to induce molecular orientation. In particular, we will review the cases involving molecular and interfacial interactions, unidirectional deposition processes, electrospinning, and postdeposition mechanical treatments. The studies presented here clearly demonstrate that process-controlled molecular orientation of the conjugated polymer chains can result in high device performances (mobilities over 40 cm2·V−1·s−1 and solar cells with efficiencies over 10%). Furthermore, the peculiar interactions between molecularly oriented polymers and polarized light have the potential not only to generate low-cost and low energy consumption polarized light sources but also to fabricate innovative devices such as solar cell integrated LCDs or bipolarized LEDs.

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Wang, Siyu, Sultan Otep, Joost Kimpel, Takehiko Mori et Tsuyoshi Michinobu. « N-Type Charge Carrier Transport Properties of BDOPV-Benzothiadiazole-Based Semiconducting Polymers ». Electronics 9, n^o 10 (1 octobre 2020) : 1604. http://dx.doi.org/10.3390/electronics9101604.

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High-performance n-type organic semiconducting polymers are key components of next-generation organic electronics. Here, we designed and synthesized two electron deficient organic polymers composed of benzodifurandione-based oligo (p-phenylenevinylene) (BDOPV) and benzothiadiazole by Stille coupling polycondensation. BDOPV-benzothiadiazole-based copolymer (PBDOPV-BTT) possesses a D-A1-D-A2 type backbone with intramolecular charge–transfer interactions, while PBDOPV-BTTz is an all-acceptor polymer. The former has a higher molecular weight (Mn) of 109.7 kg∙mol−1 than the latter (Mn = 20.2 kg∙mol−1). The structural difference of these polymers was confirmed by the optical absorption spectra. PBDOPV-BTT showed a more bathochromically shifted absorption spectrum than PBDOPV-BTTz. The longer wavelength absorption of PBDOPV-BTT was due to the intramolecular charge transfer. Therefore, PBDOPV-BTT had a narrower band gap than PBDOPV-BTTz. However, this feature was not reflected by the lowest unoccupied molecular orbital (LUMO) levels. Both polymers displayed almost the same LUMO level of −3.8 eV. Accuracy of this observation was cross-verified by density functional theory (DFT) calculations. The electron-transporting properties were investigated by thin film transistors. PBDOPV-BTT showed an electron mobility (μe) of 1.02 × 10−2 cm2 V−1 s−1 under the optimized annealing conditions. PBDOPV-BTTz exhibited poorer transistor performances with the optimized μe of 9.54 × 10−6 cm2 V−1 s−1. Finally, the grazing-incidence wide angle X-ray scattering (GIWAXS) measurements of both polymer films revealed the higher crystallinity of PBDOPV-BTT with the edge-on orientation.

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Chabinyc, Michael L., Leslie H. Jimison, Jonathan Rivnay et Alberto Salleo. « Connecting Electrical and Molecular Properties of Semiconducting Polymers for Thin-Film Transistors ». MRS Bulletin 33, n^o 7 (juillet 2008) : 683–89. http://dx.doi.org/10.1557/mrs2008.140.

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AbstractAn overview of recent work on the connection between electrical and molecular properties of semiconducting polymers for thin-film transistors (TFTs) is presented. A description of the molecular packing and microstructure of amorphous to semicrystalline semiconducting polymers is presented. The features of basic models for electrical transport in TFTs are discussed. These studies indicate that defect states and traps are as important as ordered domains for understanding transport in semiconducting polymers. Advanced methods, such as electric force microscopy, useful for measuring the characteristics of defect states and charge traps, are briefly reviewed.

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Peart, Patricia A., Giselle A. Elbaz et John D. Tovar. « Optical and electrical properties of π-conjugated polymers built with the 10 π-electron methano[10]annulene ring system ». Pure and Applied Chemistry 82, n^o 4 (17 mars 2010) : 1045–53. http://dx.doi.org/10.1351/pac-con-09-10-05.

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Nontraditional aromatic molecules hold tremendous promise for the design and realization of advanced materials for organic electronics applications. In this report, we describe recent work with the 10 π-electron methano[10]annulene molecule. We used chemistry established by Vogel and by Neidlein to incorporate this molecule into organic semiconducting polymers and found that they provide for highly delocalized charge carriers upon electrochemical oxidation/doping into conductive materials. Extensions to a variety of annulene-heteroaromatic copolymers will be described along with pertinent optical and electrical characterization data.

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Jagannath, Badrinath, Sriram Muthukumar et Shalini Prasad. « P109 PASSIVE ECCRINE SWEAT SENSING FOR DUPLEX TEMPORAL DETECTION OF CYTOKINES ». Inflammatory Bowel Diseases 26, Supplement_1 (janvier 2020) : S18. http://dx.doi.org/10.1093/ibd/zaa010.042.

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Abstract Introduction Sweat based wearable sensors have shown a lot of promise in the recent years due to the ability of tracking the biomarkers in real-time. Among the various biomarkers present in sweat, cytokine concentrations have been shown in comparable range to the blood cytokines. Detection of sweat cytokines can help in monitoring of inflammation in real-time. In this work, we demonstrate a duplex cytokine sweat based sensor for real-time monitoring. The developed sensor can detect interleukin-6 (IL-6) and interleukin-10 (IL-10) in real-time that can aid in prognosis or recovery of inflammation. Materials and Methods The sweat based sensor was developed with semiconducting electrode on porous polymeric substrate on a porous polymer substrate. Affinity capture probes were immobilized on the sensor surface via a thiol-cross linking chemistry. ATR-IR was used to validate immobilization of the capture probes. Electrochemical impedance measurements technique was used to detect the interaction between the specific antibody and target analyte. The impedance response based on the binding interaction was used to quantify the sensor metrics. Results In this work, a sweat sensor platform for the duplex detection of IL-6 and IL-10 has been demonstrated. The conjugation of the antibodies to the sensor surface was confirmed using ATR-IR spectroscopy. Impedance response was used to characterize the sensor performance metrics. Calibration dose response curve was developed with decreasing impedance response for increasing concentrations of target analyte. A limit of detection of 2 pg/mL was obtained with a dynamic range from 2 pg/mL- 200 pg/mL for IL-6. IL-10 demonstrated a limit of detection of 1.5pg/mL with a dynamic range from 1.5- 150pg/mL. The developed sensor demonstrated minimal or no cross-reactivity to non-specific molecules. Conclusion A novel sweat-based biosensor for duplex detection of cytokine markers has been demonstrated. The developed biosensor can detect pro and anti-inflammatory cytokines that can aid in the prognosis or recovery of inflammation.

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Chen, L., L. Wu, J. Yu, C. T. Kuo, T. Jian, I. C. Wu, Y. Rong et D. T. Chiu. « Highly photostable wide-dynamic-range pH sensitive semiconducting polymer dots enabled by dendronizing the near-IR emitters ». Chemical Science 8, n^o 10 (2017) : 7236–45. http://dx.doi.org/10.1039/c7sc03448b.

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Stahl, Thomas, Robin Bofinger, Ivan Lam, Kealan J. Fallon, Peter Johnson, Olumide Ogunlade, Vessela Vassileva et al. « Tunable Semiconducting Polymer Nanoparticles with INDT-Based Conjugated Polymers for Photoacoustic Molecular Imaging ». Bioconjugate Chemistry 28, n^o 6 (31 mai 2017) : 1734–40. http://dx.doi.org/10.1021/acs.bioconjchem.7b00185.

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Ou, Jiemei, Huijun Tan, Zhong Chen et Xudong Chen. « FRET-Based Semiconducting Polymer Dots for pH Sensing ». Sensors 19, n^o 6 (25 mars 2019) : 1455. http://dx.doi.org/10.3390/s19061455.

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Förster resonance energy transfer (FRET)-based polymer dots (Pdots), fabricated by semiconducting polymers and exhibiting excellent properties, have attracted much interest in the last decade, however, full polymer-dot-based pH sensors are seldom systematically exploited by researchers. In this work, we constructed a kind of blend polymer dot, utilizing poly[(9,9-dihexyl-9H-fluorene-2,7-vinylene)-co-(1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene)] (PFV) as the donor, poly[2,5-bis(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (BDMO-PPV) as the acceptor, and polysytrene graft EO functionalized with carboxy (PS-PEG-COOH) to generate surface carboxyl groups. This type of Pdot, based on the FRET process, was quite sensitive to pH value changes, especially low pH environments. When the pH value decreases down to 2 or 1, the fluorescence spectrum of Pdots-20% exhibit spectral and intensity changes at the same time, and fluorescence lifetime changes as well, which enables pH sensing applications. The sharpening of the emission peak at ~524 nm, along with the weakening and blue shifts of the emission band at ~573 nm, imply that the efficiency of the energy transfer between PFV and BDMO-PPV inside the Pdots-20% decreased due to polymer chain conformational changes. The time-resolved fluorescence measurements supported this suggestion. Pdots constructed by this strategy have great potential in many applications, such as industrial wastewater detection, in vitro and intracellular pH measurement, and DNA amplification and detection.

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Zhang, Xinan, Binghao Wang, Lizhen Huang, Wei Huang, Zhi Wang, Weigang Zhu, Yao Chen, YanLi Mao, Antonio Facchetti et Tobin J. Marks. « Breath figure–derived porous semiconducting films for organic electronics ». Science Advances 6, n^o 13 (mars 2020) : eaaz1042. http://dx.doi.org/10.1126/sciadv.aaz1042.

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Porous semiconductor film morphologies facilitate fluid diffusion and mass transport into the charge-carrying layers of diverse electronic devices. Here, we report the nature-inspired fabrication of several porous organic semiconductor-insulator blend films [semiconductor: P3HT (p-type polymer), C8BTBT (p-type small-molecule), and N2200 (n-type polymer); insulator: PS] by a breath figure patterning method and their broad and general applicability in organic thin-film transistors (OTFTs), gas sensors, organic electrochemical transistors (OECTs), and chemically doped conducting films. Detailed morphological analysis of these films demonstrates formation of textured layers with uniform nanopores reaching the bottom substrate with an unchanged solid-state packing structure. Device data gathered with both porous and dense control semiconductor films demonstrate that the former films are efficient TFT semiconductors but with added advantage of enhanced sensitivity to gases (e.g., 48.2%/ppm for NO2 using P3HT/PS), faster switching speeds (4.7 s for P3HT/PS OECTs), and more efficient molecular doping (conductivity, 0.13 S/m for N2200/PS).

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Chou, Li-Hui, Yaena Na, Chung-Hyoi Park, Min Soo Park, Itaru Osaka, Felix Sunjoo Kim et Cheng-Liang Liu. « Semiconducting small molecule/polymer blends for organic transistors ». Polymer 191 (mars 2020) : 122208. http://dx.doi.org/10.1016/j.polymer.2020.122208.

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Положенцева, Ю. А., Е. В. Алексеева et М. П. Карушев. « Полупроводниковые свойства полимерных пленок на основе комплекса никеля с лигандом саленового типа ». Физика твердого тела 64, n^o 1 (2022) : 64. http://dx.doi.org/10.21883/ftt.2022.01.51832.166.

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Complexes of metals with Schiff bases are considered as promising materials for creating energy storage and photovoltaic devices. In this work, the semiconducting properties of a polymer nickel film with a salen-type ligand (poly-Ni(CH3O-Salen)) were studied by spectrophotometric and Faraday impedance spectroscopy. The Mott-Schottky analysis showed that the polymer film is a semiconducting material with a fairly narrow band gap, high charge carrier density and p-type conductivity. Using the method of Faraday impedance spectroscopy, the limiting stage of the oxygen photoelectroreduction reaction, the process of charge transfer from the film to molecular oxygen, has been established.

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Zhu, Houjuan, Yuan Fang, Xu Zhen, Na Wei, Yu Gao, Kathy Qian Luo, Chenjie Xu et al. « Multilayered semiconducting polymer nanoparticles with enhanced NIR fluorescence for molecular imaging in cells, zebrafish and mice ». Chemical Science 7, n^o 8 (2016) : 5118–25. http://dx.doi.org/10.1039/c6sc01251e.

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Gamage, Prabhath L., Chinthaka M. Udamulle Gedara, Ruwan Gunawardhana, Chandima Bulumulla, Ziyuan Ma, Ashutosh Shrivastava, Michael C. Biewer et Mihaela C. Stefan. « Enhancement in Charge Carrier Mobility by Using Furan as Spacer in Thieno[3,2-b]Pyrrole and Alkylated-Diketopyrrolopyrrole Based Conjugated Copolymers ». Applied Sciences 12, n^o 6 (19 mars 2022) : 3150. http://dx.doi.org/10.3390/app12063150.

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The structural alteration of semiconducting polymer backbones can improve the optoelectronic properties of organic semiconductors and enhance field-effect mobilities. In our efforts towards improving the performance of organic field-effect transistors (OFETs), we are reporting a donor–acceptor polymer containing thieno[3,2-b]pyrrole (TP) donor and a furan-flanked diketopyrrolopyrrole (DPP) electron acceptor, which yielded an asymmetric poly(methylthienopyrrolo)furanyl)diketopyrrolopyrrol) P(FDPP-TP) organic semiconducting polymer. The introduction of a furan spacer improved thermally induced crystallinity and molecular packing, as confirmed by grazing incidence X-ray diffraction (XRD) and tapping-mode atomic force microscopy (TMAFM). The tested OFET devices gave maximum hole mobility of 0.42 cm2 V−1 s−1 with threshold voltages around 0 V for bottom-gate bottom-contact device configuration.

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Un Kim, Young, Gi Eun Park, Suna Choi, Dae Hee Lee, Min Ju Cho et Dong Hoon Choi. « A new n-type semiconducting molecule with an asymmetric indenothiophene core for a high-performing non-fullerene type organic solar cell ». Journal of Materials Chemistry C 5, n^o 29 (2017) : 7182–90. http://dx.doi.org/10.1039/c7tc00706j.

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Herein, a new asymmetric n-type semiconducting molecule (PhITBD) with an indenothiophene core was designed, synthesized using tethering 2-(benzo[c][1,2,5]-thiadiazol-4-ylmethylene)-malononitrile (BM) as terminal groups, and applied to polymer solar cells (PSCs).

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C. Faria, Gregório, Duc T. Duong, Giovanni Paro da Cunha, Philipp Selter, Lasse Arnt Strassø, Emily C. Davidson, Rachel A. Segalman, Michael Ryan Hansen, Eduardo Ribeiro deAzevedo et Alberto Salleo. « On the growth, structure and dynamics of P3EHT crystals ». Journal of Materials Chemistry C 8, n^o 24 (2020) : 8155–70. http://dx.doi.org/10.1039/d0tc00704h.

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We employ X-ray diffraction, NMR and UV-vis spectroscopy techniques to shed light on the structure, molecular mobility and crystallization of a prototypical semiconducting polymer poly(3-(2′-ethylhexyl)thiophene) (P3EHT).

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Dilonardo, Elena, Maria M. Giangregorio, Maria Losurdo, Pio Capezzuto, Giovanni Bruno, Antonio Cardone, Carmela Martinelli, Gianluca M. Farinola, Francesco Babudri et Francesco Naso. « Tailoring Optical Properties of Blue-Gap Poly(p-phenylene Vinylene)s for LEDs Applications ». Advances in Science and Technology 75 (octobre 2010) : 118–23. http://dx.doi.org/10.4028/www.scientific.net/ast.75.118.

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There has been growing interest in developing new semiconducting polymers for applications in optoelectronics (OLEDs) due to their exceptional processability and appealing characteristic of manipulating electronic and optical properties by tuning of molecular structure and self-assembling. This study is an investigation on the interplay among supermolecular organization and optical properties of thin films of the poly[2-(2-ethylhexyloxy)-5-methoxy]-1, 4-phenylenedifluorovinylene (MEH-PPDFV) conjugated polymer, which has fluorinated vinylene units. This interplay is elucidated exploiting atomic force microscopy, spectroscopy ellipsometry, photoluminescence and electroluminescence. Thin films of MEH-PPDFV have been deposited by drop casting on indium-tin-oxide (ITO), quartz and glass substrates. The dependence of polymer chains self-organization and morphology on substrate surface is presented. Furthermore, it is demonstrated that the presence of F-atoms in the vinylene units of the MEH-PPDFV yields a blue optical band gap with the maximum of the fundamental HOMO-LUMO transition at 331 nm and photoluminescence at 458 nm. The OLED built with the above polymer shows a very stable blue-greenish electroluminescence that is also achieved at 504 nm.

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Chandra Mondal, Kartik, Sudipta Roy, Birger Dittrich, Bholanath Maity, Sayan Dutta, Debasis Koley, Suresh Kumar Vasa, Rasmus Linser, Sebastian Dechert et Herbert W. Roesky. « A soluble molecular variant of the semiconducting silicondiselenide ». Chemical Science 6, n^o 9 (2015) : 5230–34. http://dx.doi.org/10.1039/c5sc01516b.

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Silicondiselenide is a semiconductor and exists as an insoluble polymer (SiSe₂)_nwhich is prepared by reacting elemental silicon with selenium powder in the temperature range of 400–850 °C.

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KIROVA, NATASHA. « POLARONIC EFFECTS AT THE FIELD EFFECT JUNCTIONS FOR UNCONVENTIONAL SEMICONDUCTORS ». International Journal of High Speed Electronics and Systems 17, n^o 03 (septembre 2007) : 457–64. http://dx.doi.org/10.1142/s0129156407004643.

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We consider properties of junctions for the FET geometry were molecular crystals or conducting polymers are used as semiconducting layers. In the molecular crystal Coulomb interaction of free electrons with surface polar phonons of the dielectric layer can lead to selftrapping of carriers and to the formation of a strongly coupled long-range surface polaron. The effect is further enhanced at presence of the bias electric field. The pronounced polaronic effects in conducting polymers change drastically the contact properties of these materials with respect to traditional semiconductors. Instead of the usual band banding near the contact interface, new allowed electronic bands appear inside the band gap. As a result the bias electric field and the injected charge penetrate into the polymer via creation of the soliton lattice which period changes with the distance from the contact surface. The performed studies open the possibility to describe the stationary characteristics and the hysteresis of the FET junctions and the Schottky diodes as well as to explain the photoluminescence suppression or enhancement under the bias electric field.

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Articles de revues sur le sujet « Semiconducting Polymer Molecules »

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