Endre søk
Begrens søket
1 - 33 of 33
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Angelin, Marcus
    et al.
    KTH, Skolan för teknikvetenskaplig kommunikation och lärande (ECE), Lärande.
    Rahm, M.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gumaelius, Lena
    KTH, Skolan för teknikvetenskaplig kommunikation och lärande (ECE), Lärande.
    Rocket scientist for a day: Investigating alternatives for chemical propulsion2012Inngår i: Journal of Chemical Education, ISSN 0021-9584, E-ISSN 1938-1328, Vol. 89, nr 10, s. 1301-1304Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This laboratory experiment introduces rocket science from a chemistry perspective. The focus is set on chemical propulsion, including its environmental impact and future development. By combining lecture-based teaching with practical, theoretical, and computational exercises, the students get to evaluate different propellant alternatives. To complete the task, they need to use several important curricular concepts, such as the breaking and formation of bonds, redox reactions, and thermodynamics. They also apply basic computational electronic structure calculations to investigate the energetic content of hitherto nonexisting alternatives. Finally, actual chemical rocket propulsion is demonstrated through the assembly and testing of a model rocket motor, employing a commercially available kit. The full experiment was developed for upper-level high school classes and is completed in a 3-h lab period. The experiment, or parts of it, has also been successfully used both in undergraduate programs and continuing education for teachers. 

  • 2. Ellis, Hanna
    et al.
    Eriksson, Susanna K.
    Feldt, Sandra M.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Lohse, Peter W.
    Lindblad, Rebecka
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Rensmo, Håkan
    Boschloo, Gerrit
    Hagfeldt, Anders
    Linker Unit Modification of Triphenylamine-Based Organic Dyes for Efficient Cobalt Mediated Dye-Sensitized Solar Cells2013Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, nr 41, s. 21029-21036Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Linker unit modification of donor-linker-acceptor-based organic dyes was investigated with respect to the spectral and physicochemical properties of the dyes. The spectral response for a series of triphenylamine (TPA)-based organic dyes, called LEG1-4, was shifted into the red wavelength region, and the extinction coefficient of the dyes was increased by introducing different substituted dithiophene units on the pi-conjugated linker. The photovoltaic performance of dye-sensitized solar cells (DSCs) incorporating the different dyes in combination with cobalt-based electrolytes was found to be dependent on dye binding. The binding morphology of the dyes on the TiO2 was studied using photoelectron spectroscopy, which demonstrated that the introduction of alkyl chains and different substituents on the dithiophene linker unit resulted in a larger tilt angle of the dyes with respect to the normal of the TiO2-surface, and thereby a lower surface coverage. The good photovoltaic performance for cobalt electrolyte-based DSCs found here and by other groups using TPA-based organic dyes with a cyclopentadithiophene linker unit substituted with alkyl chains was mainly attributed to the extended spectral response of the dye, whereas the larger tilt angle of the dye with respect to the TiO2-surface resulted in less efficient packing of the dye molecules and enhanced recombination between electrons in TiO2 and Co(III) species in the electrolyte.

  • 3.
    Fan, Ke
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Li, Fusheng
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Wang, Lei
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Daniel, Quentin
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi. Dalian University of Technology (DUT), China.
    Pt-free tandem molecular photoelectrochemical cells for water splitting driven by visible light2014Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, nr 46, s. 25234-25240Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Photoelectrochemical (PEC) cells using molecular catalysts to split water into hydrogen and oxygen have been investigated intensively during the past years. However, the high-cost of Pt counter electrodes and instability of molecular PEC cells hinder the practical applications. We describe in this article a Pt-free tandem molecular PEC cell, for the first time, employing molecular ruthenium- and cobalt-catalysts with strong dipicolinic acid anchoring groups on the respective photoanode and photocathode for total water splitting. The Pt-free tandem molecular PEC cell showed an effective and steady photocurrent density of ca. 25 mu A cm(-2) for water splitting driven by visible light without external bias. This study indicates that tandem molecular PEC cells can provide great potential to the Pt-free devices for light driven total water splitting.

  • 4.
    Fan, Ke
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Li, Fusheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Wang, Lei
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Quentin, Daniel
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Chen, H.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, J.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT), Dalian, China.
    Immobilization of a Molecular Ruthenium Catalyst on Hematite Nanorod Arrays for Water Oxidation with Stable Photocurrent2015Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 8, nr 19, s. 3242-3247Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Photoelectrochemical (PEC) cells for light-driven water splitting are prepared using hematite nanorod arrays on conductive glass as the photoanode. These devices improve the photocurrent of the hematite-based photoanode for water splitting, owing to fewer surface traps and decreased electron recombination resulting from the one-dimensional structure. By employing a molecular ruthenium co-catalyst, which contains a strong 2,6-pyridine-dicarboxylic acid anchoring group at the hematite photoanode, the photocurrent of the PEC cell is enhanced with high stability for over 10000s in a 1M KOH solution. This approach can pave a route for combining one-dimensional nanomaterials and molecular catalysts to split water with high efficiency and stability.

  • 5. Feldt, Sandra M.
    et al.
    Gibson, Elizabeth A.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Boschloo, Gerrit
    Hagfeldt, Anders
    Design of Organic Dyes and Cobalt Polypyridine Redox Mediators for High-Efficiency Dye-Sensitized Solar Cells2010Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 132, nr 46, s. 16714-16724Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dye-sensitized solar cells (DSCs) with cobalt-based mediators with efficiencies surpassing the record for DSCs with iodide-free electrolytes were developed by selecting a suitable combination of a cobalt polypyridine complex and an organic sensitizer. The effect of the steric properties of two triphenylamine-based organic sensitizers and a series of cobalt polypyridine redox mediators on the overall device performance in DSCs as well as on transport and recombination processes in these devices was compared. The recombination and mass-transport limitations that, previously, have been found to limit the performance of these mediators were avoided by matching the properties of the dye and the cobalt redox mediator. Organic dyes with higher extinction coefficients than the standard ruthenium sensitizers were employed in DSCs in combination with outer-sphere redox mediators, enabling thinner TiO2 films to be used. Recombination was reduced further by introducing insulating butoxyl chains on the dye rather than on the cobalt redox mediator, enabling redox couples with higher diffusion coefficients and more suitable redox potential to be used, simultaneously improving the photocurrent and photovoltage of the device. Optimization of DSCs sensitized with a triphenylamine-based organic dye in combination with tris(2,2'-bipyridyl)cobalt(II/III) yielded solar cells with overall conversion efficiencies of 6.7% and open-circuit potentials of more than 0.9 V under 1000 W m(-2) AM1.5 G illumination. Excellent performance was also found under low light intensity indoor conditions.

  • 6. Fredin, Kristofer
    et al.
    Johansson, Erik M. J.
    Hahlin, Maria
    Schölin, Rebecka
    Plogmaker, Stefan
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Rensmo, Håkan
    Solid state dye-sensitized solar cells prepared by infiltrating a molten hole conductor into a mesoporous film at a temperature below 150 degrees C2011Inngår i: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 161, nr 21-22, s. 2280-2283Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Infiltration of a molten hole conductor in a mesoporous film at an elevated temperature exhibits good wetting performance and the procedure is therefore suitable as part of the preparation method for solid state dye-sensitized solar cells. Herein, we present a system prepared by infiltrating 4-(diethylamino)benzaldehyde-1,1)-diphenyl-hydrazone in its molten form at a temperature below 150 degrees C. The system displays a maximum photon-to-current conversion efficiency of about 35%, a value corresponding to an increase of about 5 times in comparison with a previously published system prepared by infiltrating a molten hole-conductor at a temperature exceeding 250 degrees C. By means of comparing charge transport and recombination with the results measured for a liquid analogue, we conclude that whereas the transport rates are similar, recombination is significantly more rapid in the solid-state device.

  • 7.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Molecular Engineering of D-π-A Dyes for Dye-Sensitized Solar Cells2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Dye-sensitized solar cells (DSSCs) present an interesting method for the conversion of sunlight into electricity. Unlike in other photovoltaic technologies, the difficult tasks of light absorption and charge transport are handled by two different materials in DSSCs. At the heart of the DSSC, molecular light absorbers (dyes) are responsible for converting light into current.

    In this thesis the design, synthesis and properties of new metal-free D-π-A dyes for dye-sensitized solar cells will be explored. The thesis is divided into six parts:

    Part one offers a general introduction to DSSCs, dye design and device characterization.

    Part two is an investigation of a series of donor substituted dyes where structural benefits are compared against electronic benefits.

    In part three a dye assembly consisting of a chromophore tethered to two electronically decoupled donors is described. The assembly, capable of intramolecular regeneration, is found to impede recombination.

    Part four explores a method for rapidly synthesizing new D-π-A dyes by dividing them into donor, linker and acceptor fragments that can be assembled in two simple steps. The method is applied to synthesize a series of linker varied dyes for cobalt based redox mediators that builds upon the experience from part two.

    Part five describes the synthesis of a bromoacrylic acid based dye and explores the photoisomerization of a few bromo- and cyanoacrylic acid based dyes.

    Finally, in part six the experiences from previous chapters are combined in the design and synthesis of a D-π-A dye bearing a new pyridinedicarboxylic acid acceptor and anchoring group.

  • 8.
    Gabrielsson, Erik
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Ellis, Hanna
    Feldt, Sandra
    Tian, Haining
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Boschloo, Gerrit
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Convergent/Divergent Synthesis of a Linker-Varied Series of Dyes for Dye-Sensitized Solar Cells Based on the D35 Donor2013Inngår i: Advanced Energy Materials, ISSN 1614-6832, Vol. 3, nr 12, s. 1647-1656Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of four new dyes, based on the D35 type donor moiety with varied linker units, is synthesized using a facile convergent/divergent method, enabled by an improved synthesis of the D35 donor. The dyes are evaluated in dye sensitized solar cells with Co(II/III)(bpy)(3)-based electrolytes. By extending the linker fragment, higher photocurrents and solar energy conversion efficiencies are achieved. It is also found that the linker unit plays a crucial role in maintaining a high open-circuit photovoltage. Based on the photovoltaic performance it is concluded that the hexylthiophene unit is the most suitable for this purpose, as it allows further enhancement of the already high open-circuit voltage of D35 to 0.92 V. The best dye in this series reaches an efficiency of 6.8%.

  • 9.
    Gabrielsson, Erik
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hao, Yan
    Lohse, Peter William
    Johansson, Erik Martin Jesper
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    Boschloo, Gerrit
    Control of Interfacial Charge Transfer in Organic Dye-SensitizedSolar Cells Based on Cobalt ElectrolytesManuskript (preprint) (Annet vitenskapelig)
  • 10.
    Gabrielsson, Erik
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Tian, Haining
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Eriksson, Susanna K.
    Gao, Jiajia
    Chen, Hong
    Li, Fusheng
    Oscarsson, Johan
    Sun, Juliang
    Resmo, Håkan
    Kloo, lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Dipicolinic Acid: A Strong Anchoring Group with Tunable Redoxand Spectral Behavior for Stable Dye-Sensitized Solar CellsManuskript (preprint) (Annet vitenskapelig)
  • 11.
    Gabrielsson, Erik
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Tian, Haining
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. Uppsala University, Sweden.
    Eriksson, Susanna K.
    Gao, Jiajia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Chen, Hong
    Li, Fusheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Oscarsson, Johan
    Sun, Junliang
    Rensmo, Håkan
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. Dalian University of Technology (DUT), China.
    Dipicolinic acid: a strong anchoring group with tunable redox and spectral behavior for stable dye-sensitized solar cells2015Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 51, nr 18, s. 3858-3861Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dipicolinic acidwas investigated as a new anchoring group for DSSCs. A pilot dye (PD2) bearing this new anchoring group was found to adsorb significantly stronger to TiO2 than its cyanoacrylic acid analogue. The electrolyte composition was found to have a strong effect on the photoelectrochemical properties of the adsorbed dye in the device, allowing the dye LUMO energy to be tuned by 0.5 eV. Using a pyridine-free electrolyte, panchromatic absorption of the dye on TiO2 extending to 900 nm has been achieved. Solar cells using PD2 and a Co(bpy)(3) based electrolyte showed unique stability under simulated sunlight and elevated temperatures.

  • 12.
    Hagberg, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Brinck, Tove
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Linder, Mats
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Jiang, Xiao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Symmetric and Unsymmetric Donor Functionalization. Comparing Structural and Spectral Benefits of Chromophores for Dye Sensitized Solar Cells.2009Inngår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 19, s. 7232-7238Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

     

    A series of organic chromophores have been synthesized in order to investigate the benefits of structural versus spectral properties as well as the absorption properties and solar cell performance when introducing unsymmetrical substituents in the chromophore. Exceptionally high Voc was found for the symmetrical, structural benefited dye, which also gave the best overall solar cell performance.

     

  • 13. Hao, Yan
    et al.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lohse, Peter William
    Yang, Wenxing
    Johansson, Erik M. J.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. Dalian University of Technology, China.
    Boschloo, Gerrit
    Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye-Sensitized Solar Cell Performance2015Inngår i: Advanced Science, ISSN 2198-3844, Vol. 2, nr 11, artikkel-id 1500174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Investigation of charge transfer dynamics in dye-sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal-free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron-hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2 to the cobalt-based electrolyte.

  • 14.
    Jiang, Xiao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Johansson, Erik M. J.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Quintana, Maria
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Karlsson, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Boschloo, Gerrit
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Highly Efficient Solid-State Dye-Sensitized Solar Cells Based on Triphenylamine Dyes2011Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, nr 15, s. 2944-2952Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two triphenylamine-based metal-free organic sensitizers, D35 with a single anchor group and M14 with two anchor groups, have been applied in dye-sensitized solar cells (DSCs) with a solid hole transporting material or liquid iodide/triiodide based electrolyte. Using the molecular hole conductor 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenyl-amine)9,9'-spirobifluorene (spiro-OMeTAD), good overall conversion efficiencies of 4.5% for D35 and 4.4% for M14 were obtained under standard AM 1.5G illumination (100 mW cm(-2)). Although M14 has a higher molar extinction coefficient (by similar to 60%) and a slightly broader absorption spectrum compared to D35, the latter performs slightly better due to longer lifetime of electrons in the TiO(2), which can be attributed to differences in the molecular structure. In iodide/triiodide electrolyte-based DSCs, D35 outperforms M14 to a much greater extent, due to a very large increase in electron lifetime. This can be explained by both the greater blocking capability of the D35 monolayer and the smaller degree of interaction of triiodide (iodine) with D35 compared to M14. The present work gives some insight into how the molecular structure of sensitizer affects the performance in solid-state and iodide/triiodide-based DSCs.

  • 15.
    Jiang, Xiao
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagberg, Daniel P
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Structural Modification of Organic Dyes for Efficient Coadsorbent-Free Dye-Sensitized Solar Cells2010Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 114, nr 6, s. 2799-2805Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Three triphenylamine-based organic sensitizers with different electron-donating substituents (butoxyl chains or dimethylamine groups) were examined to investigate the effect of bulky alkoxy donor substituents on the photovoltaic performances of dye-sensitized solar cells (DSCs) in the presence and absence of the coadsorbent chenodeoxycholic acid (CDCA) in dye-bath solutions. The study showed that, using the D29 dye without bulky alkoxy substituents, the power conversion efficiency of DSC was significantly increased by about 84% in the presence of CDCA as compared to that in the absence of CDCA addition during the sensitization. However, the photovoltaic performance of D35-sensitized DSC having four bulky butoxyl substituents was not dependent on CDCA at all, probably due to the inherent structural nature of the D35 molecule. The DSC based on the D37 sensitizer with only two bulky butoxyl chains displayed an expected medium performance as compared to D29 and D35. The inclusion of bulky alkoxy electron-donating substituents in dye molecules for efficient DSCs suppressed the electron recombination and reduced the interactions between dye molecules. This emphasizes the importance of designing novel dyes including functional groups that incorporate the properties normally needed from an external coadsorbent. The development of a coadsorbent free system is in particular important for the future economization and simplification of the DSCs' assembly process.

  • 16. Johansson, Erik M. J.
    et al.
    Yang, Lei
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lohse, Peter W.
    Boschloo, Gerrit
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Hagfeldt, Anders
    Combining a Small Hole-Conductor Molecule for Efficient Dye Regeneration and a Hole-Conducting Polymer in a Solid-State Dye-Sensitized Solar Cell2012Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 116, nr 34, s. 18070-18078Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In dye-sensitized solar cells (DSC) an efficient transfer of dioles from the oxidized dye to the contact is necessary, which in solid-state DSC is performed by hole-conductor molecules. In this report we use photoinduced absorption and transient absorption spectroscopy to show that a small hole-conducting molecule, tris(p-anisyl)amine, regenerates dye molecules in the pores of the dye-sensitized TiO2 nanoparticle electrode efficiently even for thick (>5 mu m) electrodes. For similar thicknesses we observe incomplete regeneration using a larger polymer hole-conductor. However, the performance of the solar cells with the small hole-conductor molecules is poor due to that inefficient hole conduction in these small molecules may limit the collection of the charges at the contacts. Polymer hole-conductors, which may have a good hole conductivity, also have a high molecular weight, which makes these polymers difficult to infiltrate into the smallest pores in the electrode. We show that a conducting polymer, P3HT, may be added to the small molecule hole-conductor, to enable better transport of the charges to the contact and to reduce recombination and therefore increase the photocurrent. This new device construction with a small molecule efficiently regenerating the dye molecules, and a polymer conducting the holes to the contact is therefore a promising pathway for solid-state dye-sensitized solar cells.

  • 17.
    Karlsson, Karl Martin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Jiang, Xiao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Eriksson, Susanna K
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Rensmo, Håkan
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Phenoxazine Dyes for Dye-Sensitized Solar Cells: Relationship Between Molecular Structure and Electron Lifetime.2011Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 17, nr 23, s. 6415-6424Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of metal-free organic dyes with a core phenoxazine chromophore have been synthesized and tested as sensitizers in dye-sensitized solar cells. Overall conversion efficiencies of 6.03-7.40 % were reached under standard AM 1.5G illumination at a light intensity of 100 mW cm(-2) . A clear trend in electron lifetime could be seen; a dye with a furan-conjugated linker showed a shorter lifetime relative to dyes with the acceptor group directly attached to the phenoxazine. The addition of an extra donor unit, which bore insulating alkoxyl chains, in the 7-position of the phenoxazine could increase the lifetime even further and, together with additives in the electrolyte to raise the conduction band, an open circuit voltage of 800 mV could be achieved. From photoelectron spectroscopy and X-ray absorption spectroscopy of the dyes adsorbed on TiO(2) particles, it can be concluded that the excitation is mainly of cyano character (i.e., on average, the dye molecules are standing on, and pointing out, from the surface of TiO(2) particles).

  • 18.
    Karlsson, Karl Martin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Jiang, Xiao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Kaufmann, Susanna
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Johansson, Erik Martin Jesper
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Rensmo, Håkan
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Triphenylamine Based Organic Chromophores Containing Two Anchoring Groups for Dye Sensitized Solar CellsManuskript (preprint) (Annet vitenskapelig)
  • 19.
    Karlsson, Karl Martin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Jiang, Xiao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi (stängd 20110630). KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Tian, Haining
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Modifying the Energy Levels in Phenoxazine Based Sensitizers for Dye Sensitized Solar CellsManuskript (preprint) (Annet vitenskapelig)
  • 20. Leandri, V.
    et al.
    Ellis, H.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi. State Key Laboratory of Fine Chemicals, DUT-KTH Joint Research Center on Molecular Devices, Dalian University of Technology (DUT), China .
    Boschloo, G.
    Hagfeldt, A.
    An organic hydrophilic dye for water-based dye-sensitized solar cells2014Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, nr 37, s. 19964-19971Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study we report the first organic hydrophilic dye employed for 100% water-based electrolyte DSSCs. We show that the replacement of alkyl by glycolic chains in the dye structure is able to provide excellent wettability, resulting in an efficient system with remarkably reduced desorption problems that allowed us to perform tests over a wide pH range. By changing the electrolyte composition, employing chenodeoxycholic acid as a co-adsorbent and using PEDOT counter-electrodes, 3% power conversion efficiency under 1-sun illumination was obtained. We show that chenodeoxycholic acid does not significantly increase the wettability, and we provide new insights into the higher performance resulting from its co-adsorption.

  • 21.
    Li, Fusheng
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Fan, Ke
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Xu, Bo
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gabrielsson, Erik
    Daniel, Quentin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Li, Lin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT), Dalian, China.
    Organic Dye-Sensitized Tandem Photoelectrochemical Cell for Light Driven Total Water Splitting2015Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 137, nr 28, s. 9153-9159Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Light driven water splitting was achieved by a tandem dye-sensitized photoelectrochemical cell with two photoactive electrodes. The photoanode is constituted by an organic dye L0 as photosensitizer and a molecular complex Ru1 as water oxidation catalyst on meso-porous TiO2, while the photocathode is constructed with an organic dye P1 as photoabsorber and a molecular complex Col as hydrogen generation catalyst on nanostructured NiO. By combining the photocathode and the photoanode, this tandem DS-PEC cell can split water by visible light under neutral pH conditions without applying any bias.

  • 22.
    Marinado, Tannia
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hahlin, Maria
    Jiang, Xiao
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Quintana, Maria
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Johansson, Erik M J
    Gabrielsson, Erik
    Plogmaker, Stefan
    Hagberg, Daniel P
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Boschloo, Gerrit
    Zakeeruddin, M
    Gratzel, Michael
    Siegbahn, Hans
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Rensmo, Håkan
    Surface Molecular Quantification and Photoelectrochemical Characterization of Mixed Organic Dye and Coadsorbent Layers on TiO2 for Dye-Sensitized Solar Cells2010Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 114, nr 27, s. 11903-11910Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Different molecular layers on TiO2 were prepared by using the p-dimethylaniline triphenylamine based organic dye, D29, together with the coadsorbents decylphosphonic acid (DPA), dineohexyl bis(3,3-dimethylbutyl)phosphinic acid (DINHOP), and chenodeoxycholic acid (CDCA). The surface molecular structure of dye and coadsorbent layers on TiO2 was investigated by photoelectron spectroscopy (PES). A focus was to determine the surface molecular concentrations using characteristic photoelectron core levels. Dye-sensitized solar cells (DSCs) were prepared from the same substrate and were further characterized by photoelectrochemical methods. Together the investigation gives information on the arrangement of the mixed molecular layer and a first insight to the extent to which the coadsorbents exchange with dye molecules on the TiO2 surface for the examined conditions.

  • 23.
    Tian, Haining
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Bora, Ilkay
    KTH, Skolan för kemivetenskap (CHE), Kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Jiang, Xiao
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Modifying organic phenoxazine dyes for efficient dye-sensitized solar cells2011Inngår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, nr 33, s. 12462-12472Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Four organic dyes bearing the phenoxazine chromophore have been synthesized and applied in dye-sensitized solar cells (DSCs). The effect of different dye structures on the performance of the DSCs was investigated systematically with photophysical, photovoltaic as well as photoelectrochemical methods. Due to the slow recombination process between injected electrons and electrolyte, the IB3 dye with two 2,4-dibutoxyphenyl units showed the best efficiency of 7.0% under 100 mW cm(-2) light illumination in the liquid state-DSCs. Moreover, the phenoxazine dyes-based solid state-DSCs were fabricated for the first time. With the IB4 dye, a higher efficiency of 3.2% has been achieved under the same light intensity.

  • 24.
    Tian, Haining
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lohse, Peter William
    Vlachopoulos, Nick
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Development of an organic redox couple and organic dyes for aqueous dye-sensitized solar cells2012Inngår i: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 5, nr 12, s. 9752-9755Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A water-soluble organic redox couple (TT-/DTT) and new organic dyes (D45 and D51) have been developed for aqueous dye-sensitized solar cells (DSCs). An optimal efficiency of 3.5% was obtained using the D51 dye and an optimized electrolyte composition. The highest IPCE value obtained was 68% at 460 nm.

  • 25.
    Tian, Haining
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Yu, Ze
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    A thiolate/disulfide ionic liquid electrolyte for organic dye-sensitized solar cells based on Pt-free counter electrodes2011Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 47, nr 36, s. 10124-10126Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The ionic liquid, 1-ethyl-3-methylimidazolium tetracyanoborate, was employed to prepare a thiolate/disulfide ionic liquid electrolyte with low viscosity for organic dye-sensitized solar cells (DSCs). CoS was introduced and showed better photovoltaic performance in DSCs than the ubiquitous platinized FTO CE.

  • 26.
    Tian, Haining
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Oscarsson, Johan
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Eriksson, Susanna K.
    Lindblad, Rebecka
    Xu, Bo
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Hao, Yan
    Boschloo, Gerrit
    Johansson, Erik M. J.
    Gardner, James M.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Hagfeldt, Anders
    Rensmo, Håkan
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Enhancement of p-Type Dye-Sensitized Solar Cell Performance by Supramolecular Assembly of Electron Donor and Acceptor2014Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 4, s. 4282-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Supramolecular interactions based on porphyrin and fullerene derivatives were successfully adopted to improve the photovoltaic performance of p-type dye-sensitized solar cells (DSCs). Photoelectron spectroscopy (PES) measurements suggest a change in binding configuration of ZnTCPP after co-sensitization with C60PPy, which could be ascribed to supramolecular interaction between ZnTCPP and C60PPy. The performance of the ZnTCPP/C60PPy-based p-type DSC has been increased by a factor of 4 in comparison with the DSC with the ZnTCPP alone. At 560 nm, the IPCE value of DSCs based on ZnTCPP/C60PPy was a factor of 10 greater than that generated by ZnTCPP-based DSCs. The influence of different electrolytes on charge extraction and electron lifetime was investigated and showed that the enhanced V-oc from the Co2+/(3+)(dtbp)(3)-based device is due to the positive E-F shift of NiO.

  • 27.
    Xu, Bo
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Tian, Haining
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Bi, Dongqin
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Johansson, Erik M. J.
    Boschloo, Gerrit
    Hagfeldt, Anders
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Efficient solid state dye-sensitized solar cells based on an oligomer hole transport material and an organic dye2013Inngår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 1, nr 46, s. 14467-14470Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A low-cost and easily-synthesized organic hole transport material (HTM) X3 bearing triphenylamine units and an organic dye was utilized for solid state dye sensitized solar cells (ssDSCs), which have achieved the power conversion efficiencies of 5.8% and 7.1% under 1 sun and 0.46 sun, respectively, outperforming the ssDSC based on Spiro-OMeTAD 5.4% (1 sun) and 6.4% (0.46 sun).

  • 28.
    Xu, Yunhua
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Fischer, Andreas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi.
    Duan, Lele
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Tong, Lianpeng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Åkermark, Björn
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Chemical and Light-Driven Oxidation of Water Catalyzed by an Efficient Dinuclear Ruthenium Complex2010Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 49, nr 47, s. 8934-8937Artikkel i tidsskrift (Fagfellevurdert)
  • 29. Yang, L.
    et al.
    Lindblad, R.
    Gabrielsson, Erik
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Boschloo, G.
    Rensmo, H.
    Sun, L.
    Hagfeldt, A.
    Edvinsson, T.
    Johansson, E. M. J.
    Experimental and Theoretical Investigation of the Function of 4- tert -Butyl Pyridine for Interface Energy Level Adjustment in Efficient Solid-State Dye-Sensitized Solar Cells2018Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 14, s. 11572-11579Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    4-tert-Butylpyridine (t-BP) is commonly used in solid state dye-sensitized solar cells (ssDSSCs) to increase the photovoltaic performance. In this report, the mechanism how t-BP functions as a favorable additive is investigated comprehensively. ssDSSCs were prepared with different concentrations of t-BP, and a clear increase in efficiency was observed up to a maximum concentration and for higher concentrations the efficiency thereafter decreases. The energy level alignment in the complete devices was measured using hard X-ray photoelectron spectroscopy (HAXPES). The results show that the energy levels of titanium dioxide are shifted further away from the energy levels of spiro-OMeTAD as the t-BP concentration is increased. This explains the higher photovoltage obtained in the devices with higher t-BP concentration. In addition, the electron lifetime was measured for the devices and the electron lifetime was increased when adding t-BP, which can be explained by the recombination blocking effect at the surface of TiO2. The results from the HAXPES measurements agree with those obtained from density functional theory calculations and give an understanding of the mechanism for the improvement, which is an important step for the future development of solar cells including t-BP.

  • 30. Yang, Lei
    et al.
    Cappel, Ute B.
    Unger, Eva L.
    Karlsson, Martin
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Boschloo, Gerrit
    Hagfeldt, Anders
    Johansson, Erik M. J.
    Comparing spiro-OMeTAD and P3HT hole conductors in efficient solid state dye-sensitized solar cells2012Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 14, nr 2, s. 779-789Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two hole conductor materials, spiro-OMeTAD and P3HT, were compared in solid-state dye-sensitized solar cells. Two organic dyes containing one anchor unit (D35) or two anchor units (M3) were used in the comparison. Absorbed photon to current conversion efficiency close to unity was obtained for the devices with spiro-OMeTAD. Energy conversion efficiencies of 4.7% and 4.9% were measured for the devices with spiro-OMeTAD and the dyes D35 and M3, respectively. For the devices using the P3HT hole conductor the results were rather different comparing the two dye molecules, with energy conversion efficiencies of 3.2% and 0.5% for D35 and M3, respectively. Photo-induced absorption measurements suggest that the regeneration of the dyes, and the polymer infiltration, is not complete using P3HT, while spiro-OMeTAD regenerates the dyes efficiently. However, the TiO(2)/D35/P3HT system shows rather high energy conversion efficiency and electrochemical oxidation of the dyes on TiO(2) indicates that D35 have a more efficient dye to dye hole conduction than M3, which thereby might explain the higher performance. The dye hole conduction may therefore be of significant importance for optimizing the energy conversion in such hybrid TiO(2)/dye/polymer systems.

  • 31.
    Yu, Ze
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi (stängd 20110630).
    Tian, Haining
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Boschloo, Gerrit
    Uppsala University, Sweden.
    Gorlov, Mikhail
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi (stängd 20110630).
    Tetrathiafulvalene as a one-electron iodine-free organic redox mediator in electrolytes for dye-sensitized solar cells2012Inngår i: RSC Advances, ISSN 2046-2069, Vol. 2, nr 3, s. 1083-1087Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tetrathiafulvalene (TTF) was investigated as an organic iodine-free redox mediator in electrolytes for dye-sensitized, nanocrystalline solar cells (DSCs) and was compared to the commonly used iodide/triiodide system. The TTF system studied was determined to be a one-electron transfer system, although potentially exhibiting three well-defined oxidation states. Despite the slightly positive redox potential of TTF, electrolytes with TTF displayed around 200 mV lower open-circuit voltage than the iodide/triiodide system. This can mainly be ascribed to a much shorter electron lifetime in the TiO2 film. Mass transport limitations for redox species in TTF-based electrolytes were found to be serious. Electrochemical impedance measurements (EIS) show that the charge-transfer resistance at the counter electrode in the electrolyte with TTF is considerably larger than for the iodide/triiodide system. In addition, the light absorption of the TTF-based electrolyte is stronger than that for the iodide/triiodide system. Thus, DSCs with TTF-based electrolytes show worse photovoltaic performance than those with iodide/triiodide-based electrolytes. The differences in IV characteristics and charge-recombination behavior have also been elucidated.

  • 32. Zhang, Jinbao
    et al.
    Yang, Lei
    Shen, Yang
    Park, Byung-Wook
    Hao, Yan
    Johansson, Erik M. J.
    Boschloo, Gerrit
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Jarboui, Adel
    Perruchot, Christian
    Jouini, Mohamed
    Vlachopoulos, Nick
    Hagfeldt, Anders
    Poly(3,4-ethylenedioxythiophene) Hole-Transporting Material Generated by Photoelectrochemical Polymerization in Aqueous and Organic Medium for All-Solid-State Dye-Sensitized Solar Cells2014Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 118, nr 30, s. 16591-16601Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We applied organic donor-pi-acceptor (D-pi-A) sensitizers for photoelectrochemical polymerization (PEP) because of their appropriate energy levels and high light absorption. The polymerized conducting polymer PEDOT was used as hole conductor in all-solid-state dye-sensitized solar cells (ssDSCs). By combination of the D-pi-A sensitizers and the generated PEDOT from PEP of bis-EDOT in acetonitrile, the resulting device showed an average power conversion efficiency of 5.6%. Furthermore, the PEP in aqueous micellar electrolytic medium was also employed because of the ability to decrease oxidation potential of the precursor, thereby making the polymerization process easier. The latter method is a cost-effective and environmentally friendly approach. Using as hole conductor the so-obtained PEDOT from PEP of bis-EDOT in aqueous electrolyte, the devices exhibited impressive power conversion efficiency of 5.2%. To compare the properties of the generated polymer from bis-EDOT in these two PEP methods, electron lifetime, photoinduced absorption (PIA) spectra, and UV-vis-NIR spectra were measured. The results showed that PEDOT from organic PEP exhibits a delocalized conformation with high conductivity and a smooth and compact morphology; a rough morphology with high porosity and polymer structure of relatively shorter chains was assumed to be obtained from aqueous PEP. Therefore, better dye regeneration but faster charge recombination was observed in the device based on PEDOT from aqueous PEP of bis-EDOT. Subsequently, to extend the aqueous PEP approach in consideration of the ability to decrease the oxidation potential of the precursor, the easily available precursor EDOT was for the first time used for PEP in aqueous medium in a variant of the aforementioned procedure, and the device based on the so-obtained PEDOT shows a more than 70-fold increase in efficiency, 3.0%, over that based on the polymer generated from EDOT by PEP in organic media. It was demonstrated that aqueous micellar PEP with EDOT as monomer is an efficient strategy for generation of conducting polymer hole-transporting materials.

  • 33. Zietz, Burkhard
    et al.
    Gabrielsson, Erik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Johansson, Viktor
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    El-Zohry, Ahmed M.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Photoisomerization of the cyanoacrylic acid acceptor group - a potential problem for organic dyes in solar cells2014Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, nr 6, s. 2251-2255Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Organic solar cell dyes containing the most common anchoring group, cyanoacrylic acid, are shown to be photolabile and undergo photoisomerization. This may have significant consequences for dye-sensitized solar cells, as isomerisation competes with electron injection and leads to modifications of the dye and surface arrangement.

1 - 33 of 33
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf