| 1. |
- Ajjan, Fátima, et al.
(författare)
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Scalable Asymmetric Supercapacitors Based on Hybrid Organic/Biopolymer Electrodes
- 2017
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Ingår i: ADVANCED SUSTAINABLE SYSTEMS. - : WILEY-V C H VERLAG GMBH. - 2366-7486. ; 1:8
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Tidskriftsartikel (refereegranskat)abstract
- A trihybrid bioelectrode composed of lignin, poly(3,4-ethylenedioxythiophene) (PEDOT), and poly(aminoanthraquinone) (PAAQ) is prepared by a two-step galvanostatic electropolymerization, and characterized for supercapacitor applications. Using PEDOT/Lignin as a base layer, followed by the consecutive deposition of PAAQ, the hybrid electrode PEDOT/Lignin/PAAQ shows a high specific capacitance of 418 F g(-1) with small self-discharge. This trihybrid electrode material can be assembled into symmetric and asymmetric super-capacitors. The asymmetric supercapacitor uses PEDOT + Lignin/PAAQ as positive electrode and PEDOT/PAAQ as negative electrode, and exhibits superior electrochemical performance due to the synergistic effect of the two electrodes, which leads to a specific capacitance of 74 F g(-1). It can be reversibly cycled in the voltage range of 0-0.7 V. More than 80% capacitance is retained after 10 000 cycles. These remarkable features reveal the exciting potential of a full organic energy storage device with long cycle life.
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| 2. |
- Bergqvist, Jonas, et al.
(författare)
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Asymmetric photocurrent extraction in semitransparent laminated flexible organic solar cells
- 2018
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Ingår i: npj Flexible Electronics. - : Springer Science and Business Media LLC. - 2397-4621. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Scalable production methods and low-cost materials with low embodied energy are key to success for organic solar cells. PEDOT(PSS) electrodes meet these criteria and allow for low-cost and all solution-processed solar cells. However, such devices are prone to shunting. In this work we introduce a roll-to-roll lamination method to construct semitransparent solar cells with a PEDOT(PSS) anode and an polyethyleneimine (PEI) modified PEDOT(PSS) cathode. We use the polymer:PCBM active layer coated on the electrodes as the lamination adhesive. Our lamination method efficiently eliminates any shunting. Extended exposure to ambient degrades the laminated devices, which manifests in a significantly reduced photocurrent extraction when the device is illuminated through the anode, despite the fact that the PEDOT(PSS) electrodes are optically equivalent. We show that degradation-induced electron traps lead to increased trap-assisted recombination at the anode side of the device. By limiting the exposure time to ambient during production, degradation is significantly reduced. We show that lamination using the active layer as the adhesive can result in device performance equal to that of conventional sequential coating.
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| 3. |
- Ever Aguirre, Luis, et al.
(författare)
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Diatom frustules protect DNA from ultraviolet light
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- The evolutionary causes for generation of nano and microstructured silica by photosynthetic algae are not yet deciphered. Diatoms are single photosynthetic algal cells populating the oceans and waters around the globe. They generate a considerable fraction (20-30%) of all oxygen from photosynthesis, and 45% of total primary production of organic material in the sea. There are more than 100,000 species of diatoms, classified by the shape of the glass cage in which they live, and which they build during algal growth. These glass structures have accumulated for the last 100 million of years, and left rich deposits of nano/microstructured silicon oxide in the form of diatomaceous earth around the globe. Here we show that reflection of ultraviolet light by nanostructured silica can protect the deoxyribonucleic acid (DNA) in the algal cells, and that this may be an evolutionary cause for the formation of glass cages. © 2018 The Author(s).
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| 4. |
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| 5. |
- Ouyang, Liangqi, et al.
(författare)
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The contraction of PEDOT films formed on a macromolecular liquid-like surface
- 2018
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 6:3, s. 654-660
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Tidskriftsartikel (refereegranskat)abstract
- Vapour phase polymerized (VPP) PEDOT obtained using triblock copolymer PEG-PPG-PEG: Fe(III) tosylate polymeric oxidative layers has shown record-high conductivity and unique thermoelectric properties. These properties are related to the molecular weight, morphology and doping of PEDOT. Here we show that in its unwashed condition, the PEDOT chain adopts a neutral benzenoid conformation. The polymer chain converts into the charged quinoid structure after the removal of oxidizers with solvent washing. X-ray diffraction results suggest that the dopant is also incorporated into the packed polymer after the washing process. The changes in the chain structure and doping lead to the characteristic polaron and bipolaron absorption in the 800 and 1200 nm range. We observed a large contraction of the film after washing that is likely due to these changes, along with the removal of excessive polymer: oxidizer trapped in the PEDOT matrix. The contraction of films can be completely suppressed by mechanical clamping. PEDOT films without contraction show both a higher conductivity and higher optical transparency.
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| 6. |
- Rodriguez Martinez, Xabier, et al.
(författare)
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Laminated Organic Photovoltaic Modules for Agrivoltaics and Beyond: An Outdoor Stability Study of All-Polymer and Polymer:Small Molecule Blends
- 2023
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 33:10
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Tidskriftsartikel (refereegranskat)abstract
- The integration of organic photovoltaic (OPV) modules on greenhouses is an encouraging practice to offset the energy demands of crop growth and provide extra functionality to dedicated farmland. Nevertheless, such OPV devices must meet certain optical and stability requirements to turn net zero energy greenhouse systems a reality. Here a donor:acceptor polymer blend is optimized for its use in laminated devices while matching the optical needs of crops. Optical modeling is performed and a greenhouse figure-of-merit is introduced to benchmark the trade-off between photovoltaic performance and transparency for both chloroplasts and humans. Balanced donor:acceptor ratios result in better-performing and more thermally stable devices than acceptor-enriched counterparts. The optimized polymer blend and state-of-the-art polymer:small-molecule blends are next transferred to 25 cm(2) laminated modules processed entirely from solution and in ambient conditions. The modules are mounted on a greenhouse as standalone or 4-terminal tandem configurations and their outdoor stability is tracked for months. The study reveals degradation modes undetectable under laboratory conditions such as module delamination, which accounts for 10-20% loss in active area. Among the active layers tested, polymer:fullerene blends are the most stable and position as robust light harvesters in future building-integrated OPV systems.
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| 7. |
- Xia, Yuxin, et al.
(författare)
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All-Polymer High-Performance Photodetector through Lamination
- 2020
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Ingår i: Advanced Electronic Materials. - : WILEY. - 2199-160X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- All-polymer and semitransparent organic photodetectors (OPDs) fabricated through lamination on flexible substrates are demonstrated. Through lamination both bilayer and bulk heterojunction (BHJ) configurations for two different all-polymer blends are easily made, and characterized in terms of detectivity, linear dynamic range (LDR), and bandwidth. These devices show high detectivity up to 10(11) Jones. The importance of measured noise rather than estimated shot noise in detectivity calculation is discussed and emphasized. With this high detectivity and with the geometric flexibility due to the polymer materials, these detectors can be attached to curved surfaces for optical detection. Their use at fingertips for heart rate sensing is demonstrated. These devices also have a very wide bandwidth of more than 300 kHz and an LDR of 75 dB. As such the, roll-to-roll compatible lamination method shows great potential for high-performance OPDs fabrication.
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| 8. |
- Xia, Yuxin, et al.
(författare)
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Semitransparent all-polymer solar cells through lamination
- 2018
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 6:42, s. 21186-21192
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we demonstrate all-polymer solar cells where all the layers are made from polymers. We use PEDOT:PSS as the semitransparent anode and polyethyleneimine modified PEDOT:PSS as the semitransparent cathode, both of which are slot-die printed on polyethylene terephthalate (PET). Active layers are deposited on the cathode and anode surfaces by spin coating separately. These layers are then joined through a roll-to-roll compatible lamination process. This results in a semitransparent and flexible solar cell. We have used two polymer-polymer systems and several combinations, and the highest power conversion efficiency (PCE) obtained is 2.3% with a mean transparency amp;gt;35% within the visible light range. By laminating a thin layer acceptor polymer to a thick polymer-polymer blend, we can improve the performance by reducing recombination, compared to laminating blend to blend, which is verified by the trap-limited charge transport, CELIV and electroluminescence.
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