| 1. |
- Abdollahi Sani, Negar, et al.
(author)
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A ferroelectric polymer introduces addressability in electrophoretic display cells
- 2019
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In: FLEXIBLE AND PRINTED ELECTRONICS. - : IOP PUBLISHING LTD. - 2058-8585. ; 4:3
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Journal article (peer-reviewed)abstract
- During the last decades, tremendous efforts have been carried out to develop flexible electronics for a vast array of applications. Among all different applications investigated in this area, flexible displays have gained significant attention, being a vital part of large-area devices, portable systems and electronic labels etc electrophoretic (EP) ink displays have outstanding properties such as a superior optical switch contrast and low power consumption, besides being compatible with flexible electronics. However, the EP ink technology requires an active matrix-addressing scheme to enable exclusive addressing of individual pixels. EP ink pixels cannot be incorporated in low cost and easily manufactured passive matrix circuits due to the lack of threshold voltage and nonlinearity, necessities to provide addressability. Here, we suggest a simple method to introduce nonlinearity and threshold voltage in EP ink display cells in order to make them passively addressable. Our method exploits the nonlinearity of an organic ferroelectric capacitor that introduces passive addressability in display cells. The organic ferroelectric material poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) is here chosen because of its simple manufacturing protocol and good polarizability. We demonstrate that a nonlinear EP cell with bistable states can be produced by depositing a P(VDF-TrFE) film on the bottom electrode of the display cell. The P(VDF-TrFE) capacitor and the EP ink cell are separately characterized in order to match the surface charge at their respective interfaces and to achieve and optimize bistable operation of display pixels.
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| 2. |
- Deribew, Dargie, et al.
(author)
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Crystallization-Driven Enhancement in Photovoltaic Performance through Block Copolymer Incorporation into P3HT:PCBM Blends
- 2013
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In: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 46:8, s. 3015-3024
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Journal article (peer-reviewed)abstract
- We report the increased crystallization of poly(3-hexylthiophene)(P3HT) in the donor−acceptor mixture of [6,6]-phenyl-C61-butyric acid methylester (PCBM) with P3HT by the addition of a block copolymer, P3HT-b-PI, where PI refers to polyisoprene. The photovoltaic performance of devices created using this blendis markedly improved by the addition of the diblock copolymer. We have characterizedthe structure of thin films of the P3HT-b-PI containing mixtures using opticalmicroscopy, scanning force microscopy, UV−vis absorption spectroscopy, neutronreflectometry, and grazing incidence X-ray diffraction (GIXD). The GIXD data providethe information on the crystallinity of the films, the absorption data were used toconfirm that the addition of the diblock was responsible for the increase in crystallization, neutron reflectometry data reveal a PCBM-rich region near the hole injection layer, and the two microscopy techniques revealed the structural effect of the crystallization at the surface of the films.
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| 3. |
- Hofmann, Anna, 1987, et al.
(author)
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Materials for Transparent Electrodes: From Metal Oxides to Organic Alternatives
- 2018
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In: Advanced Electronic Materials. - : Wiley. - 2199-160X .- 2199-160X. ; 4:10
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Research review (peer-reviewed)abstract
- Optoelectronic devices, such as displays, are now omnipresent in our daily life. A crucial component of these devices is a transparent electrode, which allows the in- and outcoupling of light. With the goal of optimizing the electrode characteristics and improving device efficiencies, many approaches for the fabrication of thin, transparent, conducting films have been studied. This review gives an overview of the different material classes which are used as transparent electrodes, ranging from metal oxides, such as indium tin oxide, metal, and carbonaceous nanostructures, to conducting polymers and composites. For every material class, a brief description of the fundamental principles, processing routes, and the latest achievements is given. Furthermore, the optoelectronic performance, flexibility, and surface roughness of the different electrodes are compared. Ultimately, advantages and drawbacks of the respective electrodes are discussed. This critical comparison of fundamentally different transparent conducting materials allows, on one hand, to make a sensible choice of electrode for specific applications, and, on the other hand, to point out scientific challenges that must still be addressed.
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| 4. |
- Mantione, Daniele, et al.
(author)
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Thiophene-Based Trimers for In Vivo Electronic Functionalization of Tissues
- 2020
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In: ACS APPLIED ELECTRONIC MATERIALS. - : AMER CHEMICAL SOC. - 2637-6113. ; 2:12, s. 4065-4071
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Journal article (peer-reviewed)abstract
- Electronic materials that can self-organize in vivo and form functional components along the tissue of interest can result in a seamless integration of the bioelectronic interface. Previously, we presented in vivo polymerization of the conjugated oligomer ETE-S in plants, forming conductors along the plant structure. The EDOT-thiophene-EDOT trimer with a sulfonate side group polymerized due to the native enzymatic activity of the plant and integrated within the plant cell wall. Here, we present the synthesis of three different conjugated trimers based on thiophene and EDOT or purely EDOT trimers that are able to polymerize enzymatically in physiological pH in vitro as well as in vivo along the roots of living plants. We show that by modulating the backbone and the side chain, we can tune the electronic properties of the resulting polymers as well as their localization and penetration within the root. Our work paves the way for the rational design of electronic materials that can self-organize in vivo for spatially controlled electronic functionalization of living tissue.
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| 5. |
- Parker, Daniela, et al.
(author)
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Biohybrid plants with electronic roots via in vivo polymerization of conjugated oligomers
- 2021
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In: Materials Horizons. - : Royal Society of Chemistry. - 2051-6347 .- 2051-6355. ; 8:12, s. 3295-3305
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Journal article (peer-reviewed)abstract
- Plant processes, ranging from photosynthesis through production of biomaterials to environmental sensing and adaptation, can be used in technology via integration of functional materials and devices. Previously, plants with integrated organic electronic devices and circuits distributed in their vascular tissue and organs have been demonstrated. To circumvent biological barriers, and thereby access the internal tissue, plant cuttings were used, which resulted in biohybrids with limited lifetime and use. Here, we report intact plants with electronic functionality that continue to grow and develop enabling plant-biohybrid systems that fully maintain their biological processes. The biocatalytic machinery of the plant cell wall was leveraged to seamlessly integrate conductors with mixed ionic-electronic conductivity along the root system of the plants. Cell wall peroxidases catalyzed ETE-S polymerization while the plant tissue served as the template, organizing the polymer in a favorable manner. The conductivity of the resulting p(ETE-S) roots reached the order of 10 S cm(-1) and remained stable over the course of 4 weeks while the roots continued to grow. The p(ETE-S) roots were used to build supercapacitors that outperform previous plant-biohybrid charge storage demonstrations. Plants were not affected by the electronic functionalization but adapted to this new hybrid state by developing a more complex root system. Biohybrid plants with electronic roots pave the way for autonomous systems with potential applications in energy, sensing and robotics.
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| 6. |
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| 7. |
- Petsagkourakis, Ioannis, et al.
(author)
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Correlating the Seebeck coefficient of thermoelectric polymer thin films to their charge transport mechanism
- 2018
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In: Organic electronics. - : ELSEVIER SCIENCE BV. - 1566-1199 .- 1878-5530. ; 52, s. 335-341
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Journal article (peer-reviewed)abstract
- Room temperature flexible heat harvesters based on conducting polymers are ideally suited to cover the energy demands of the modern nomadic society. The optimization of their thermoelectric efficiency is usually sought by tuning the oxidation levels of the conducting polymers, even if such methodology is detrimental to the Seebeck coefficient (S) as both the Seebeck coefficient and the electrical conductivity (sigma) are antagonistically related to the carrier concentration. Here we report a concurrent increase of S and sigma and we experimentally derive the dependence of Seebeck coefficient on charge carrier mobility for the first time in organic electronics. Through specific control of the conducting polymer synthesis, we enabled the formation of a denser percolation network that facilitated the charge transport and the thermodiffusion of the charge carriers inside the conducting polymer layer, while the material shifted from a Fermi glass towards a semi-metal, as its crystallinity increased. This work sheds light upon the origin of the thermoelectric properties of conducting polymers, but also underlines the importance of enhanced charge carrier mobility for the design of efficient thermoelectric polymers.
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| 8. |
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| 9. |
- Routier, Cyril, et al.
(author)
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Chitosan-modified polyethyleneimine nanoparticles for enhancing the carboxylation reaction and plants' CO2 uptake
- 2023
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In: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 17:4, s. 3430-3441
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Journal article (peer-reviewed)abstract
- Increasing plants' photosynthetic efficiency is a major challenge that must be addressed in order to cover the food demands of the growing population in the changing climate. Photosynthesis is greatly limited at the initial carboxylation reaction, where CO2 is converted to the organic acid 3-PGA, catalyzed by the RuBisCO enzyme. RuBisCO has poor affinity for CO2, but also the CO2 concentration at the RuBisCO site is limited by the diffusion of atmospheric CO2 through the various leaf compartments to the reaction site. Beyond genetic engineering, nanotechnology can offer a materials-based approach for enhancing photosynthesis, and yet, it has mostly been explored for the light-dependent reactions. In this work, we developed polyethyleneimine-based nanoparticles for enhancing the carboxylation reaction. We demonstrate that the nanoparticles can capture CO2 in the form of bicarbonate and increase the CO2 that reacts with the RuBisCO enzyme, enhancing the 3-PGA production in in vitro assays by 20%. The nanoparticles can be introduced to the plant via leaf infiltration and, because of the functionalization with chitosan oligomers, they do not induce any toxic effect to the plant. In the leaves, the nanoparticles localize in the apoplastic space but also spontaneously reach the chloroplasts where photosynthetic activity takes place. Their CO2 loading-dependent fluorescence verifies that, in vivo, they maintain their ability to capture CO2 and can be therefore reloaded with atmospheric CO2 while in planta. Our results contribute to the development of a nanomaterials-based CO2-concentrating mechanism in plants that can potentially increase photosynthetic efficiency and overall plants' CO2 storage.
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