| 1. |
|
|
| 2. |
- Admassie, Shimelis, et al.
(författare)
-
A polymer photodiode using vapour-phase polymerized PEDOT as an anode
- 2006
-
Ingår i: Solar Energy Materials & Solar Cells. ; 90:2, s. 133-141
-
Tidskriftsartikel (refereegranskat)abstract
- We report the photovoltaic properties of devices made using a highly conducting polymer electrode, from vapor-phase polymd. poly (3,4-ethylenedioxy) thiophene (VPP PEDOT) on glass substrate as an anode and a polyfluorene copolymer poly[2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2thienyl-2',1'3'-benzothiadiazole)] (APFO-3) mixed with [6,6]-phenyl-C61-butyric acid methylester (PCBM) in the ratio of 1:4 as the active layer. The device performance was compared with that of devices made with PEDOT-PSS on glass substrates. The surfaces of VPP PEDOT were imaged using at. force microscopy (AFM). [on SciFinder (R)]
|
|
| 3. |
- Admassie, Shimelis, et al.
(författare)
-
A renewable biopolymer cathode with multivalent metal ions for enhanced charge storage
- 2014
-
Ingår i: JOURNAL OF MATERIALS CHEMISTRY A. - : Royal Society of Chemistry. - 2050-7488. ; 2:6, s. 1974-1979
-
Tidskriftsartikel (refereegranskat)abstract
- A ternary composite supercapacitor electrode consisting of phosphomolybdic acid (HMA), a renewable biopolymer, lignin, and polypyrrole was synthesized by a simple one-step simultaneous electrochemical deposition and characterized by electrochemical methods. It was found that the addition of HMA increased the specific capacitance of the polypyrrole-lignin composite from 477 to 682 F g(-1) ( at a discharge current of 1 A g(-1)) and also significantly improved the charge storage capacity from 6(to 128 mA h g(-1).
|
|
| 4. |
- Admassie, Shimelis, et al.
(författare)
-
Biopolymer hybrid electrodes for scalable electricity storage
- 2016
-
Ingår i: Materials Horizons. - : ROYAL SOC CHEMISTRY. - 2051-6347 .- 2051-6355. ; 3:3, s. 174-185
-
Forskningsöversikt (refereegranskat)abstract
- Powering the future, while maintaining a cleaner environment and a strong socioeconomic growth, is going to be one of the biggest challenges faced by mankind in the 21st century. The first step in overcoming the challenge for a sustainable future is to use energy more efficiently so that the demand for fossil fuels can be reduced drastically. The second step is a transition from the use of fossil fuels to renewable energy sources. In this sense, organic electrode materials are becoming increasingly attractive compared to inorganic electrode materials which have reached a plateau regarding performance and have severe drawbacks in terms of cost, safety and environmental friendliness. Using organic composites based on conducting polymers, such as polypyrrole, and abundant, cheap and naturally occurring biopolymers rich in quinones, such as lignin, has recently emerged as an interesting alternative. These materials, which exhibit electronic and ionic conductivity, provide challenging opportunities in the development of new charge storage materials. This review presents an overview of recent developments in organic biopolymer composite electrodes as renewable electroactive materials towards sustainable, cheap and scalable energy storage devices.
|
|
| 5. |
- Admassie, Shimelis, et al.
(författare)
-
Charge storage properties of biopolymer electrodes with (sub)tropical lignins
- 2014
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 16:45, s. 24681-24684
-
Tidskriftsartikel (refereegranskat)abstract
- The electrochemical and charge storage properties of different lignins inside biopolymer electrodes were studied and correlated with the chemical variations of the lignins as indicated from the nuclear magnetic resonance (NMR) spectroscopic data. The varying fractions of monolignols were found to correlate with charge storage properties. It was found that as the sinapyl to guaiacyl (S/G) ratio increased both the specific capacitance and charge capacity increased considerably. This indicates that quinones generated on S-units can contribute more to charge storage in the biopolymer electrodes.
|
|
| 6. |
- Admassie, Shimelis, et al.
(författare)
-
Electrochemical and optical studies of the band gaps of alternating polyfluorene copolymers
- 2006
-
Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 156:7-8, s. 614-623
-
Tidskriftsartikel (refereegranskat)abstract
- The electrochemical and optical properties of a series of alternating polyfluorene copolymers with low band gaps were determined. These polymers incorporated fluorene units alternating with groups including electron-withdrawing (A) and electron-donating (D) groups in donor-acceptor-donor (DAD) sequence to achieve the lowering of band gaps. The polymers were solvent-casted on platinum disk electrode and the band gaps were estimated from cyclic voltammetry (CV). These values were compared with values obtained from optical absorption measurements. Although the electrochemically determined band gaps were found to be slightly higher than the optical band gap in most cases, values are well correlated. The values of the band gaps determined range from 2.1 to 1.3 eV. © 2006 Elsevier B.V. All rights reserved.
|
|
| 7. |
- Admassie, Shimelis, et al.
(författare)
-
Electrochemical and optical studies of the band gaps of alternating polyfluorene copolymers
- 2006
-
Ingår i: Synthetic Metals. ; 156:7-8, s. 614-623
-
Tidskriftsartikel (refereegranskat)abstract
- The electrochem. and optical properties of alternating polyfluorene copolymers with low band gaps were detd. These polymers incorporated fluorene units alternating with groups including electron-withdrawing (A) and electron-donating (D) groups in donor-acceptor-donor (DAD) sequence to achieve the lowering of band gaps. The polymers were solvent-casted on Pt disk electrode and the band gaps were estd. from cyclic voltammetry (CV). These values were compared with values obtained from optical absorption measurements. Although the electrochem. detd. band gaps are slightly higher than the optical band gap in most cases, values are well correlated. The values of the band gaps detd. range from 2.1 to 1.3 eV. [on SciFinder (R)]
|
|
| 8. |
- Admassie, Shimelis, et al.
(författare)
-
Synthesis, optical and electrochemical characterization of anthrancene and benzothiadiazole-containing polyfluorene copolymers
- 2006
-
Ingår i: Bulletin of the Chemical Society of Ethiopia. - 1011-3924 .- 1726-801X. ; 20:2, s. 309-317
-
Tidskriftsartikel (refereegranskat)abstract
- New solution-processable, anthrancene- and benzothiadiazole-containing polyfluorene copolymers (P1-P3) have been synthesized and characterized. The preparation and characterization of the corresponding blue light-emitting devices are also reported. Polymers P2 and P3 show high photoluminescence efficiency while polymer P2 does not show any significant light emission up to 8.0 V. The results show the need for balance of electron and hole transport in polymer light emitting diodes.
|
|
| 9. |
- Gadisa, Abay, et al.
(författare)
-
A new donor-acceptor-donor polyfluorene copolymer with balanced electron and hole mobility
- 2007
-
Ingår i: Adv. Funct. Mater. FIELD Full Journal Title:Advanced Functional Materials. ; 17:18, s. 3836-3842
-
Tidskriftsartikel (refereegranskat)abstract
- A new alternating polyfluorene copolymer poly[2,7-(9,9-dioctylfluoren)-alt-5,5-(5',8'-di-2-thienyl-(2',3'-bis-(3''-octyloxyphenyl)-quinoxaline))] (APFO-15), which has electron donor-acceptor-donor units in between the fluorene units, is synthesized and characterized. This polymer has a strong absorption and emission in the visible range of the solar spectrum. Its electroluminescence and photolumin escence emissions extend from about 560 to 900 nm. Moreover, solar cells with efficiencies in excess of 3.5 % have been realized from blends of APFO-15 and an electron acceptor mol., a mathanofullerene [6,6]-phenyl-C61-butyric acid Me ester (PCBM). It has also been obsd. that electron and hole transport is balanced both in the pure polymer phase and in polymer/PCBM bulk heterojunction films, which makes this material quite attractive for applications in opto-electronic devices. [on SciFinder (R)]
|
|
| 10. |
- Gadisa, Abay, et al.
(författare)
-
Stoichiometry dependence of charge transport in polymer/methanofullerene and polymer/C70 derivative based solar cells
- 2006
-
Ingår i: Organic electronics. - : Elsevier BV. - 1566-1199. ; 7:4, s. 195-204
-
Tidskriftsartikel (refereegranskat)abstract
- Charge transport in a near infrared absorbing polyfluorene copolymer (APFO-Green1) and its blends with methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and 3′-(3,5-bis-trifluoromethylphenyl)-1′-(4-nitrophenyl)pyrazolino[70]fullerene (BTPF70) is reported. PCBM and BTPF70 are electron acceptor and transporting molecules in polymer based solar cells. The BTPF70 has emerged as a new electron acceptor molecule that provides adequate exciton dissociation when blended with the low band gap polyfluorene copolymer APFO-Green1. Electron transport in both net PCBM and BTPF70 films are subjected to positional and energetic disorder, with the degree of disorder being more pronounced in BTPF70. On the other hand, mixing PCBM with conjugated polymers usually leads to increased hole mobility. We have investigated and compared the acceptor concentration dependence of charge transport in APFO-Green1/PCBM and APFO-Green1/BTPF70 blend films. For better understanding of the charge transport in the heterojunction films, the field and temperature dependence of hole transport in pure APFO-Green1 films has also been studied. It is observed that the behavior of hole mobility in the blend layer is sensitive to the acceptor type. For APFO-Green1/PCBM hole only devices, the hole mobility attains a local maximum at 67 wt.% of PCBM, while on the contrary mixing any amount of BTPF70 with APFO-Green1 results into degradation of hole transport. Electron transport in both blends, however, increases monotonically as a function of acceptor loading.
|
|
| 11. |
- Gadisa, Abay, et al.
(författare)
-
Stoichiometry dependence of charge transport in polymer/methanofullerene and polymer/C70 derivative based solar cells
- 2006
-
Ingår i: Organic Electronics. ; 7:4, s. 195-204
-
Tidskriftsartikel (refereegranskat)abstract
- Charge transport in a near IR absorbing polyfluorene copolymer (APFO-Green1) and its blends with methanofullerene [6,6]-Ph C61-butyric acid Me ester (PCBM), and 3'-(3,5-bis-trifluoromethylphenyl)-1'-(4-nitrophenyl)pyrazolino[70]fullerene (BTPF70) is reported. PCBM and BTPF70 are electron acceptor and transporting mols. in polymer based solar cells. The BTPF70 has emerged as a new electron acceptor mol. that provides adequate exciton dissocn. when blended with the low band gap polyfluorene copolymer APFO-Green1. Electron transport in both net PCBM and BTPF70 films are subjected to positional and energetic disorder, with the degree of disorder being more pronounced in BTPF70. On the other hand, mixing PCBM with conjugated polymers usually leads to increased hole mobility. We have investigated and compared the acceptor concn. dependence of charge transport in APFO-Green1/PCBM and APFO-Green1/BTPF70 blend films. For better understanding of the charge transport in the heterojunction films, the field and temp. dependence of hole transport in pure APFO-Green1 films has also been studied. It is obsd. that the behavior of hole mobility in the blend layer is sensitive to the acceptor type. For APFO-Green1/PCBM hole only devices, the hole mobility attains a local max. at 67 wt.% of PCBM, while on the contrary mixing any amt. of BTPF70 with APFO-Green1 results into degrdn. of hole transport. Electron transport in both blends, however, increases monotonically as a function of acceptor loading. [on SciFinder (R)]
|
|
| 12. |
- Gadisa, Abay, et al.
(författare)
-
Transparent polymer cathode for organic photovoltaic devices
- 2006
-
Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 156:16-17, s. 1102-1107
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a prototype solar cell with a transparent polymer cathode, and indium-tin-oxide (ITO)/poly (3, 4-ethylene dioxythiophene)-poly (styrene sulphonate) (PEDOT:PSS) anode. As an active layer, thin film of a bulk heterojunction of polyfluorene copolymer poly[2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4′,7′-di-2thienyl-2′,1′3′-benzothiadiazole)] (APFO-3) and an electron acceptor molecule [6] and [6]-phenyl-C61-butyric acid methyl ester (PCBM) (1:4 wt.) was sandwiched between the two transparent polymer electrodes. The cathode is another form of PEDOT formed by vapor phase polymerised PEDOT (VPP PEDOT) of conductivity 102–103 S/cm. The cathode is supported on an elastomeric substrate, and forms a conformal contact to the APFO-3/PCBM blend. Transparent solar cells are useful for building multilayer and tandem solar cells.
|
|
| 13. |
- Gadisa, Abay, et al.
(författare)
-
Transparent polymer cathode for organic photovoltaic devices
- 2006
-
Ingår i: Synthetic Metals. ; 156:16-17, s. 1102-1107
-
Tidskriftsartikel (refereegranskat)abstract
- A prototype solar cell with a transparent polymer cathode and an ITO/poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) anode was fabricated. As an active layer, a thin film of a bulk heterojunction of polyfluorene copolymer, poly[2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (APFO-3) and an electron acceptor mol. [6,6]-phenyl-C61-butyric acid Me ester (PCBM) (1:4 by wt.) was sandwiched between the 2 transparent polymer electrodes. The cathode is another form of PEDOT formed by vapor phase polymd. PEDOT (VPP PEDOT) with a cond. 102-103 S/cm. The cathode is supported on an elastomeric substrate and forms a conformal contact to the APFO-3/PCBM blend. Transparent solar cells are useful for building multilayer and tandem solar cells. [on SciFinder (R)]
|
|
| 14. |
- Genene, Zewdneh, 1983, et al.
(författare)
-
Comparative study on the effects of alkylsilyl and alkylthio side chains on the performance of fullerene and non-fullerene polymer solar cells
- 2020
-
Ingår i: Organic Electronics: physics, materials, applications. - : Elsevier BV. - 1566-1199. ; 77
-
Tidskriftsartikel (refereegranskat)abstract
- Two novel high gap donor polymers – PBDTTSi-TzBI and PBDTTS-TzBI, based on imide-fused benzotriazole (TzBI) with asymmetric side chains and alkylsilyl (Si) or alkylthio (S) substituted 4,8-di(thien-2-yl)benzo-[1,2-b:4,5-b′]dithiophene (BDTT) – are successfully synthesized. The effect of the side chain variation on the photophysical, morphological and photovoltaic properties of blends of these polymers with fullerene and non-fullerene acceptors is investigated. The PBDTTSi-TzBI polymer shows a deeper highest occupied molecular orbital energy level, which results in higher open-circuit voltages. Nevertheless, the polymer solar cells fabricated using PBDTTS-TzBI in combination with PC71BM afford a higher power conversion efficiency of 7.3% (vs 4.0% for PBDTTSi-TzBI:PC71BM). By using the non-fullerene acceptor ITIC, the absorption of the blends extends to 850 nm and better device efficiencies are achieved, 6.9% and 9.6% for PBDTTSi-TzBI:ITIC and BDTTS-TzBI:ITIC, respectively. The better performance of the PBDTTS-TzBI:ITIC-based devices is attributed to the strong and broad absorption and balanced charge transport, and is among the best performances reported for non-fullerene solar cells based on TzBI-containing polymer donors.
|
|
| 15. |
- Inganäs, Olle, et al.
(författare)
-
25th Anniversary Article: Organic Photovoltaic Modules and Biopolymer Supercapacitors for Supply of Renewable Electricity: A Perspective from Africa
- 2014
-
Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095. ; 26:6, s. 830-847
-
Forskningsöversikt (refereegranskat)abstract
- The role of materials in civilization is well demonstrated over the centuries and millennia, as materials have come to serve as the classifier of stages of civilization. With the advent of materials science, this relation has become even more pronounced. The pivotal role of advanced materials in industrial economies has not yet been matched by the influence of advanced materials during the transition from agricultural to modern societies. The role of advanced materials in poverty eradication can be very large, in particular if new trajectories of social and economic development become possible. This is the topic of this essay, different in format from the traditional scientific review, as we try to encompass not only two infant technologies of solar energy conversion and storage by means of organic materials, but also the social conditions for introduction of the technologies. The development of organic-based photovoltaic energy conversion has been rapid, and promises to deliver new alternatives to well-established silicon photovoltaics. Our recent development of organic biopolymer composite electrodes opens avenues towards the use of renewable materials in the construction of wooden batteries or supercapacitors for charge storage. Combining these new elements may give different conditions for introduction of energy technology in areas now lacking electrical grids, but having sufficient solar energy inputs. These areas are found close to the equator, and include some of the poorest regions on earth.
|
|
| 16. |
|
|
| 17. |
- Lindgren, Lars Johan, 1977, et al.
(författare)
-
Blue light-emitting diodes based on novel polyfluorene copolymers
- 2007
-
Ingår i: Journal of Luminescence. ; 122-123, s. 610-613
-
Konferensbidrag (refereegranskat)abstract
- This study presents the synthesis and characterization of a series of fluorene-based conjugated copolymers, together with the prepn. and characterization of the corresponding light-emitting devices. The polymers consist of alkoxyphenyl-substituted fluorene units together with different amts. of a hole-transporting triphenylamine-substituted fluorene unit: 0%, 10%, 25% and 50%. All polymers (P0, P1, P2, and P3) show high photoluminescence efficiency (hPL) and light emission (both PL and EL) in the blue spectral region. Electrochem. studies show improved hole injection as the ratio of the triphenylamine-substituted segment is increased. The electroluminescence quantum efficiencies (EQEs) of the devices increase six times going from P0 to P1. Compared with P1, polymers P2 and P3 show lower efficiencies in devices. These findings indicate the presence of an optimal polymer compn., where balance between the charge-carrier mobilities has been reached. [on SciFinder (R)]
|
|
| 18. |
- Mammo, Wendimagegn, 1954, et al.
(författare)
-
New low band gap alternating polyfluorene copolymer-based photovoltaic cells
- 2007
-
Ingår i: Sol. Energy Mater. Sol. Cells FIELD Full Journal Title:Solar Energy Materials & Solar Cells. ; 91:11, s. 1010-1018
-
Tidskriftsartikel (refereegranskat)abstract
- New low band gap alternating polyfluorene copolymers were synthesized for use in plastic solar cells and their optical, electrochem., and photovoltaic characteristics were detd. These polymers incorporated fluorene units alternating with groups including electron-withdrawing (A) and electron-donating (D) groups in donor-acceptor-donor (DAD) sequence to achieve the lowering of band gaps. The HOMO-LUMO values were estd. from electrochem. studies. By varying the donor and acceptor strength and position of the solubilizing substituents, similar HOMO values were obtained. These values were also found to correlate well with the open circuit voltage (VOC) values detd. from photovoltaic data of the polymers blended with the acceptor PCBM. Despite similar HOMO values, the absorption spectra of the polymers differ significantly. This prompted the prepn. of photovoltaic devices consisting of blends of two polymers with complementary absorptions in combination with PCBM to harvest more photons in the polymer solar cells. [on SciFinder (R)]
|
|
| 19. |
- Negash, Asfaw, et al.
(författare)
-
Diketopyrrolopyrrole-based terpolymers with tunable broad band absorption for fullerene and fullerene-free polymer solar cells
- 2019
-
Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry (RSC). - 2050-7534 .- 2050-7526. ; 7:11, s. 3375-3384
-
Tidskriftsartikel (refereegranskat)abstract
- A series of random terpolymers with donor-acceptor-donor-acceptor molecular configuration, comprising fluorinated benzotriazole (FTAZ) and thienothiophene-capped diketopyrrolopyrrole (TTDPP) as the first and second electron-accepting moieties and thienyl-substituted benzodithiophene (BDTT) as the electron-donating unit, are designed for polymer solar cells. By tuning the ratio of TTDPP and FTAZ, the optoelectronic properties of the terpolymers are systematically varied. All materials exhibit a broad absorption window spanning from 300 to 900 nm, illustrating the success of the terpolymer approach. Fullerene-based polymer solar cells fabricated from the terpolymer with the highest content of TTDPP afford a power conversion efficiency of 5.7%, with a short-circuit current density of 15.2 mA cm -2 . On the other hand, solar cell devices composed of the terpolymer with the lowest content of TTDPP and the narrow gap non-fullerene acceptor IEICO-4F exhibit a higher efficiency of 6.3%, with an enhanced short-circuit current density of 17.5 mA cm -2 , as a result of a better complementarity in the absorption of the donor and acceptor materials and well-balanced charge carrier mobilities. This efficiency represents the best value for fullerene-free polymer solar cells based on DPP-containing polymers to date.
|
|
| 20. |
- Negash, Asfaw, et al.
(författare)
-
Exploring the High-Temperature Window of Operation for Organic Photovoltaics: A Combined Experimental and Simulations Study
- 2024
-
Ingår i: Advanced Materials for Optics and Electronics. - 1616-301X .- 1616-3028. ; 34:6
-
Tidskriftsartikel (refereegranskat)abstract
- The global climate change negatively affects the photovoltaic performance of traditional solar cell technologies. This article investigates the potential of organic photovoltaics (OPV) for high-temperature environments, ranging from urban hot summers (30—40 °C) and desert regions (65 °C) up to (aero) space conditions (130 °C), the thermal window in which OPV can operate. The approach is based on a combination of experiments and simulations up to 180 °C, moving significantly beyond the conventional temperature ranges reported in the literature. New 2H-benzo[d][1,2,3]triazole-5,6-dicarboxylic imide-based copolymers with decomposition onset temperatures above 340 °C are used for this study, in combination with non-fullerene acceptors. Contrary to their inorganic counterparts, OPV devices show a positive temperature coefficient up to ≈90 °C. At temperatures of 150 °C, they are still operational, retaining their room temperature efficiency. Complementary simulations are performed using an in-house developed software package that numerically solves the drift-diffusion equations to understand the general trends in the obtained current–voltage characteristics and the materials’ intrinsic behavior as a function of temperature. The presented methodology of combined high-temperature experiments and simulations can be further applied to investigate the thermal window of operation for other OPV material systems, opening novel high-temperature application routes.
|
|
| 21. |
- Negash, Asfaw, et al.
(författare)
-
Ladder-type high gap conjugated polymers based on indacenodithieno[3,2-b]thiophene and bithiazole for organic photovoltaics
- 2019
-
Ingår i: Organic Electronics: physics, materials, applications. - : Elsevier BV. - 1566-1199. ; 74, s. 211-217
-
Tidskriftsartikel (refereegranskat)abstract
- © 2019 Elsevier B.V. Two push-pull type conjugated polymers - PIDTT−BTz and PIDTT−DTBTz, based on the ladder-type donor unit indacenodithieno[3,2-b]thiophene (IDTT) and bithiazole (BTz) as acceptor component - are designed and synthesized for photovoltaic applications. The polymers exhibit relatively high optical gaps of ~2.0 eV with strong absorption in the range of 400–600 nm, rendering them of particular interest for the harvesting of indoor light and/or multijunction devices. Electrochemical investigations indicate a lower highest occupied molecular orbital energy level (−5.44 eV) for PIDTT−BTz as compared to PIDTT−DTBTz (−5.36 eV), enabling to achieve a higher open-circuit voltage. Under solar illumination, the best power conversion efficiency (5.1%) is achieved for the combination PIDTT−DTBTz:PC71BM (compared to 4.6% for PIDTT−BTz:PC71BM).
|
|
| 22. |
- Patil, Nagaraj, et al.
(författare)
-
Bioinspired Redox-Active Catechol-Bearing Polymers as Ultrarobust Organic Cathodes for Lithium Storage
- 2017
-
Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 29:40
-
Tidskriftsartikel (refereegranskat)abstract
- Redox-active catechols are bioinspired precursors for ortho-quinones that are characterized by higher discharge potentials than para-quinones, the latter being extensively used as organic cathode materials for lithium ion batteries (LIBs). Here, this study demonstrates that the rational molecular design of copolymers bearing catechol-and Li+ ion-conducting anionic pendants endow redox-active polymers (RAPs) with ultrarobust electrochemical energy storage features when combined to carbon nanotubes as a flexible, binder-, and metal current collector-free buckypaper electrode. The importance of the structure and functionality of the RAPs on the battery performances in LIBs is discussed. The structure-optimized RAPs can store high-capacities of 360 mA h g(-1) at 5C and 320 mA h g(-1) at 30C in LIBs. The high ion and electron mobilities within the buckypaper also enable to register 96 mA h g(-1) (24% capacity retention) at an extreme C-rate of 600C (6 s for total discharge). Moreover, excellent cyclability is noted with a capacity retention of 98% over 3400 cycles at 30C. The high capacity, superior active-material utilization, ultralong cyclability, and excellent rate performances of RAPs-based electrode clearly rival most of the state-of-the-art Li+ ion organic cathodes, and opens up new horizons for large-scalable fabrication of electrode materials for ultrarobust Li storage.
|
|
| 23. |
|
|
| 24. |
- Wang, Xiangjun, et al.
(författare)
-
Enhanced photocurrent spectral response in low-bandgap polyfluorene and C70-Derivative-Based Solar Cells
- 2005
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 15:10, s. 1665-1670
-
Tidskriftsartikel (refereegranskat)abstract
- Plastic solar cells have been fabricated using a low-bandgap alternating copolymer of fluorene and a donor-acceptor-donor moiety (APFO-Green1), blended with 3-(3,5-bis-trifluoromethylphenyl)-1-(4-nitrophenyl)pyrazolino[70]fullerene (BTPF70) as electron acceptor. The polymer shows optical absorption in two wavelength ranges, < 500 nm and 600 < < 1000 nm. The BTPF70 absorbs light at < 700 nm. A broad photocurrent spectral response in the wavelength range 300 < < 1000 nm is obtained in solar cells. A photocurrent density of 3.4 mA cm-2, open-circuit voltage of 0.58 V, and power-conversion efficiency of 0.7 % are achieved under illumination of AM1.5 (1000 W m-2) from a solar simulator. Synthesis of BTPF70 is presented. Photoluminescence quenching and electrochemical studies are used to discuss photoinduced charge transfer.
|
|
| 25. |
- Wang, Xiangjun, et al.
(författare)
-
Enhanced photocurrent spectral response in low-bandgap polyfluorene and C70-derivative-based solar cells
- 2005
-
Ingår i: Advanced Functional Materials. ; 15:10, s. 1665-1670
-
Tidskriftsartikel (refereegranskat)abstract
- Plastic solar cells have been fabricated using a low-bandgap alternating copolymer of fluorene and a donor-acceptor-donor moiety (APFO-Green1), blended with 3'-(3,5-bis-trifluoromethylphenyl)-1'-(4-nitrophenyl)pyrazolino fullerene (BTPF70) as electron acceptor. The polymer shows optical absorption in two wavelength ranges, l
|
|
