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  • 1. Fredin, Kristofer
    et al.
    Anderson, Kenrick F.
    Duffy, Noel W.
    Wilson, Gregory J.
    Fell, Christopher J.
    Hagberg, Daniel P.
    KTH, Skolan för kemivetenskap (CHE).
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Bach, Udo
    Lindquist, Sten-Eric
    Effect on Cell Efficiency following Thermal Degradation of Dye-Sensitized Mesoporous Electrodes Using N719 and D5 Sensitizers2009Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, nr 43, s. 18902-18906Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work examines the comparative durability of two common dyes at temperatures that may be experienced during fabrication of dye-sensitized solar cells (DSCs) such as through the application of thermoplastics for encapsulation or the use of a molten solid-state hole conductor. Dye-sensitized electrodes were heated in an atmosphere of air or nitrogen and thereafter used as working electrodes in DSCs. Electrodes sensitized with N719 appeared more sensitive to thermal degradation than electrodes sensitized with D5, although absorbance measurements suggest similar first-order degradation rates for the two dyes. Intensity modulated photovoltage spectroscopy and intensity modulated photocurrent spectroscopy were used to measure the effect of heating on electron lifetime and transport. It was found that the electron diffusion length may.. be as low as 10% for heated samples, compared to that of the unheated counterpart, and therefore, we assess recombination as an additional efficiency limiting process in our experiments.

  • 2.
    Hagberg, Daniel
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Synthesis of Organic Chromophores for Dye Sensitized Solar Cells.2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

     

    This thesis deals with development and synthesis of organic chromophores for dye sensitized solar cells. The chromophores are divided into three components; donor, linker and acceptor.

    The development of efficient organic chromophores for dye sensitized solar cells starts off with one new organic chromophore, D5. This chromophore consists of a triphenylamine moiety as an electron donor, a conjugated linker with a thiophene moiety and cyanoacrylic acid as an electron acceptor and anchoring group. Alternating the donor, linker or acceptor moieties independently, would give us the tool to tune the HOMO and LUMO energy levels of the chromophores. The following parts of this thesis regard this development strategy.

    The contributions to the HOMO and LUMO energy levels were investigated when alternating the linker moiety. Unexpected effects of the solar cell performances when increasing the linker length were revealed, however.

    In addition, the effect of an alternative acceptor group, rhodanine-3-acetic acid, in combination with different linker lengths was investigated. The HOMO and LUMO energy level tuning was once again successful. Electron recombination from the semiconductor to the electrolyte is probably the cause of the poor efficiencies obtained for this series of dyes.

    Finally, the development of functionalized triphenylamine based donors and the contributions from different substituents to the HOMO and LUMO energy levels and as insulating layers were investigated. This strategy has so far been the most successful in terms of reaching high efficiencies in the solar cell. A top overall efficiency of 7.79 % was achieved.

     

  • 3.
    Hagberg, Daniel
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Synthesis of Organic Chromophores for Dye Sensitized Solar Cells2007Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis is divided into four parts with organic chromophores for dye sensitized solar cells as the common feature and an introduction with general concepts of the dye sensitized solar cells.

    The first part of the thesis describes the development of an efficient organic chromophore for dye sensitized solar cells. The chromophore consists of a triphenylamine moiety as an electron donor, a conjugated linker with a thiophene moiety and cyanoacrylic acid as an electron acceptor and anchoring group. During this work a strategy to obtain an efficient sensitizer was developed. Alternating the donor, linker or acceptor moieties independently, would give us the tool to tune the HOMO and LUMO energy levels of the chromophores. The following parts of this thesis regard this development strategy.

    The second part describes the contributions to the HOMO and LUMO energy levels when alternating the linker moiety. By varying the linker the HOMO and LUMO energy levels was indeed shifted. Unexpected effects of the solar cell performances when increasing the linker length were revealed, however.

    The third part describes the investigation of an alternative acceptor group, rhodanine-3-acetic acid, in combination with different linker lengths. The HOMO and LUMO energy level tuning was once again successfully shifted. The poor electronic coupling of the acceptor group to the semiconductor surface proved to be a problem for the overall efficiency of the solar cell, however.

    The fourth part describes the contributions from different donor groups to the HOMO and LUMO energy levels and has so far been the most successful in terms of reaching high efficiencies in the solar cell. A top overall efficiency of 7.1 % was achieved.

  • 4.
    Hagberg, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi.
    Molecular Engineering of Organic Chromophores for Dye Sensitized Solar Cell Applications2008Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, s. 6259-6266Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Novel unsymmetrical organic sensitizers comprising donor, electron-conducting, and anchoring groups were engineered at a molecular level and synthesized for sensitization of mesoscopic titanium dioxide injection solar cells. The unsymmetrical organic sensitizers 3-(5-(4-(diphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid (D5), 3-(5-bis(4-(diphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid (D7), 5-(4-(bis(4-methoxyphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid (D9), and 3-(5-bis(4,4'-dimethoxydiphenylamino)styryl)thiophen-2-yl)-2-cyanoacrylic acid (D11) anchored onto TiO2 and were tested in dye-sensitized solar cell with a volatile electrolyte. The monochromatic incident photon-to-current conversion efficiency of these sensitizers is above 80%, and D11-sensitized solar cells yield a short-circuit photocurrent density of 13.90 +/- 0.2 mA/cm(2), an open-circuit voltage of 740 +/- 10 mV, and a fill factor of 0.70 +/- 0.02, corresponding to an overall conversion efficiency of 7.20% under standard AM 1.5 sun light. Detailed investigations of these sensitizers reveal that the long electron lifetime is responsible for differences in observed open-circuit potential of the cell. As an alternative to liquid electrolyte cells, a solid-state organic hole transporter is used in combination with the D9 sensitizer, which exhibited an efficiency of 3.25%. Density functional theory/time-dependent density functional theory calculations have been employed to gain insight into the electronic structure and excited states of the investigated species.

  • 5.
    Hagberg, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi (stängd 20110630).
    Edvinsson, Tomas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi (stängd 20110630).
    Boschloo, Gerrit
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi (stängd 20110630).
    Brinck, Tore
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi (stängd 20110630).
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi (stängd 20110630).
    Rhodanine Dyes for Dye Sensitized Solar Cells: Spectroscopy, Energy Levels and Photovoltaic Performance2009Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 11, s. 133-141Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Three new sensitizers for photoelectrochemical solar cells were synthesized consisting of a triphenylamine donor, a rhodanine-3-acetic acid acceptor and a polyene connection. The conjugation length was systematically increased, which resulted in two effects: first, it led to a red-shift of the optical absorption of the dyes, resulting in an improved spectral overlap with the solar spectrum. Secondly, the oxidation potential decreased systematically. The excited state levels were, however, calculated to be nearly stationary. The experimental trends were in excellent agreement with density functional theory (DFT) computations. The photovoltaic performance of this set of dyes as sensitizers in mesoporous TiO2 solar cells was investigated using electrolytes containing the iodide/triiodide redox couple. The dye with the best absorption characteristics showed the poorest solar cell efficiency, due to losses by recombination of electrons in TiO2 with triiodide. Addition of 4-tert butylpyridine to the electrolyte led to a strongly reduced photocurrent for all dyes due to a reduced electron injection efficiency, caused by a 0.15 V negative shift of the TiO2 conduction band potential.

  • 6.
    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.

     

  • 7.
    Hagberg, Daniel P.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Edvinsson, Tomas
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Boschloo, Gerrit
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    A novel organic chromophore for dye-sensitized nanostructured solar cells2006Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, nr 21, s. 2245-2247Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel and efficient polyene-diphenylaniline dye for dye-sensitized solar cells has been synthesized. The dye has a short synthesis route and is readily adsorbed on TiO2 under a variety of dye-bath conditions. The overall solar-to-energy conversion efficiency is over 5% in the preliminary tests, in comparison with the conventional N719 dye which gives 6% under the same conditions. The dye is designed for future use also in solid state devices, with triarylamine based hole conductors.

  • 8.
    Hagberg, Daniel P.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Design and synthesis of organic chromophores for dye sensitized solar cells - 12008Inngår i: ACS National Meeting Book of Abstracts, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The demand for alternative power sources has drawn the attention to a variety of light harvesting devices. Among these, the dye sensitized solar cells (DSSCxs) have attracted a number of research groups in the last decades. Here we present a series of organic chromophores based on a by us published dye, D5. To extend the spectral response of the D5 chromophore compared to N719 and to fine tune the HOMO and LUMO energy levels of the sensitizers on a molecular level, a number of modifications can be made. The chromophores consist of donor, linker and acceptor groups, which can be alternated independently to tune the HOMO and LUMO energy level contributions of different groups and to attain a HOMO and LUMO energy library.

  • 9.
    Hagberg, Daniel P.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Nonomura, Kazeteru
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Qin, Peng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Boschloo, Gerrit
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Brinck, Tore
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Tuning the HOMO and LUMO Energy Levels of Organic Chromophores For Dye Sensitized Solar Cells2007Inngår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, nr 72, s. 9550-9556Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of organic chromophores have been synthesized in order to approach optimal energy level composition in the TiO2-dye-iodide/triiodide system in the dye-sensitized solar cells. HOMO and LUMO energy level tuning is achieved by varying the conjugation between the triphenylamine donor and the cyanoacetic acid acceptor. This is supported by spectral and electrochemical experiments and TDDFT calculations. These results show that energetic tuning of the chromophores was successful and fulfilled the thermodynamic criteria for dye-sensitized solar cells, electrical losses depending on the size and orientation of the chromophores were observed.

  • 10.
    Hagberg, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    A Light Resistant Organic Sensitizer for Solar Cell Applications2009Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 48, s. 1576-1580Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    (Figure Presented) Finely tuned: A stable dye-sensitized solar cell that contains a molecularly engineered organic dye has been prepared. The efficiency of the cell remains at 90% after 1000 h of light soaking at 60 °C. The remarkable stability of the cell is also reflected in the open-circuit voltage value (Voc), short-circuit photocurrent-density value (J sc), and the fill factor, which also show barely no decline (see picture).

  • 11.
    Hagberg, Daniel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Karlsson, Karl Martin
    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.
    Highly efficient Organic Sensitizers for Solid State Dye Sensitized Solar Cells2009Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, nr 38, s. 16816-16820Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Organic sensitizers comprising of donor, electron-conducting, and anchoring groups designed and developed for dye-sensitized solar cell applications. The solar cell employing a spiro-OMeTAD hole transporting material exhibits a short circuit photocurrent density of 9.64 mA/cm2, the open circuit voltage of 798 mV and a fill factor of 0.57, corresponding to an overall conversion efficiency of 4.4% at standard AM 1.5 sunlight. Photo-induced absorption spectroscopy probes an efficient hole-transfer from dyes to the spiro-OMeTAD.

  • 12. Hahlin, Maria
    et al.
    Johansson, Erik M. J.
    Plogmaker, Stefan
    Odelius, Michael
    Hagberg, Daniel
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Siegbahn, Hans
    Rensmo, Hakan
    Electronic and molecular structures of organic dye/TiO2 interfaces for solar cell applications: a core level photoelectron spectroscopy study2010Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 12, nr 7, s. 1507-1517Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The electronic and molecular properties of three organic dye molecules with the general structure donor-linker-anchor have been investigated using core level photoelectron spectroscopy (PES). The molecules contain a diphenylaniline donor unit, a thiophene linker unit, and cyanoacrylic acid or rhodanine-3-acetic acid anchor units. They have been investigated both in the form of a multilayer and adsorbed onto nanoporous TiO2 and the experimental results were also compared with DFT calculations. The changes at the dye-sensitized TiO2 surface due to the modification of either the donor unit or the anchor unit was investigated and the results showed important differences in coverage as well as in electronic and molecular surface properties. By measuring the core level binding energies, the sub-molecular properties were characterized and the result showed that the adsorption to the TiO2 influences the energy levels of the sub-molecular units differently.

  • 13. Hahlin, Maria
    et al.
    Odelius, Michael
    Magnuson, Martin
    Johansson, Erik M. J.
    Plogmaker, Stefan
    Hagberg, Daniel P.
    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.
    Siegbahn, Hans
    Rensmo, Håkan
    Mapping the frontier electronic structures of triphenylamine based organic dyes at TiO2 interfaces2011Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 13, nr 8, s. 3534-3546Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The frontier electronic structures of a series of organic dye molecules containing a triphenylamine moiety, a thiophene moiety and a cyanoacrylic acid moiety have been investigated by photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES) and resonant photoelectron spectroscopy (RPES). The experimental results were compared to electronic structure calculations on the molecules, which are used to confirm and enrich the assignment of the spectra. The approach allows us to experimentally measure and interpret the basic valence energy level structure in the dye, including the highest occupied energy level and how it depends on the interaction between the different units. Based on N 1s X-ray absorption and emission spectra we also obtain insight into the structure of the excited states, the molecular orbital composition and dynamics. Together the results provide an experimentally determined energy level map useful in the design of these types of materials. Included are also results indicating femtosecond charge redistribution at the dye/TiO2 interface.

  • 14.
    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.

  • 15.
    Karlsson, K. Martin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Hagberg, Daniel P.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Design and synthesis of novel organic chromophores for dye sensitized solar cells - 22008Inngår i: ACS National Meeting Book of Abstracts, 2008, s. ORGN 493-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    One of the main issues of today is the energy problem where the use of fossil fuels has lead to environmental changes. The development of environmentally friendly alternatives is therefore of great importance. The sun is the perfect energy source since it supplies the earth with much more energy than we currently need. The development of dye sensitized solar cells (DSSC's) is one possible low cost alternative to harvest the solar energy. Here we present a series of different organic dyes for DSSC's in our search for better understanding of the dye's influence on the solar cell's performance. The aim of this work has been to alter the linker between the donor and acceptor parts in the chromophore in order to investigate how this will influence light absorption and efficiency of the solar cell.

  • 16. Kuang, Daibin
    et al.
    Comte, Pascal
    Zakeeruddin, Shaik M.
    Hagberg, Daniel P.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Karlsson, Karl Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Nazeeruddin, Md K.
    Grätzel, Michael
    Stable dye-sensitized solar cells based on organic chromophores and ionic liquid electrolyte2011Inngår i: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 85, nr 6, s. 1189-1194Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of polyene-diphenylaniline based organic dyes (coded as D5, D7, D9 and D11) have been reported for the application in ionic liquid electrolyte based dye-sensitized solar cells. The effects of substitution of organic dyes on the photovoltaic performance have been investigated, which show addition of methoxy groups on the triphenylamine donor group increases short-circuit current, open-circuit voltage and photovoltaic performance. A power conversion efficiency of 6.5% under AM 1.5 sunlight at 100 mW/cm(2) has been obtained with D11 dye in combination with a binary ionic liquid electrolyte, which when subjected to accelerated testing under one sun light soaking at 60 degrees C, the efficiency remained 90% of initial efficiency.

  • 17.
    Marinado, Tannia
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagberg, Daniel P.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Edvinsson, Tomas
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Brinck, Tore
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Boschloo, Gerrit
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Tian, Haining
    Yang, Xixhuan
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Energy level tuning of organic dyes for fundamental studies of the oxide/dye/electrolyte interface in solar cellsManuskript (Annet vitenskapelig)
  • 18.
    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.

  • 19.
    Marinado, Tannia
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Nonomura, Kazuteru
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Nissfolk, Jarl
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Karlsson, Martin K
    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, Organisk kemi.
    Mori, Shogo
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    How the Nature of Triphenylamine-Polyene Dyes in Dye-Sensitized Solar Cells Affects the Open-Circuit Voltage and Electron Lifetimes2010Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 26, nr 4, s. 2592-2598Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Three donor-linker-acceptor triphenylamine-based cyanoacrylic acid organic dyes used For dye-sensitized solar cells (DSCs) have been examined with respect to their effect on the open-circuit voltage (V-oc). Our previous study showed a decrease in V-oc for DSCs based oil dyes with increased molecular size (increased linker conjugation). In the present study, we investigate the origin of V-oc with respect to (i) conduction band (E-CB) positions of TiO2 and (ii) degree of recombination between electrons in TiO2 and electrolyte acceptor species at the interface. These parameters were Studied its it function of dye structure, dye load, and I-2 concentration. Two types of behavior were identified: the smaller polyene dyes show a surface-protecting effect preventing recombination upon increased dye loading, whereas the larger dyes enhance the recombination. How the different dye structures affect the recombination is discussed in terms of dye surface blocking and intermolecular interactions between dyes and electrolyte acceptor species.

  • 20.
    Nonomura, Kazuteru
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Xu, Yunhua
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagberg, Daniel P.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Zhang, Rong
    Boschloo, Gerrit
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    The Effect of UV-Irradiation (under Short-Circuit Condition) on Dye-Sensitized Solar Cells Sensitized with a Ru-Complex Dye Functionalized with a (diphenylamino)Styryl-Thiophen Group2009Inngår i: International Journal of Photoenergy (Online), ISSN 1110-662X, E-ISSN 1687-529XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new ruthenium complex, cis-di(thiocyanato)(2,2'-bipyridine-4,4'-dicarboxylic acid)(4,4'-bis(2-(5-(2-(4-diphenylaminophenyl)ethenyl)-thiophen-2-yl)eth enyl)-2,2'-bipyridine)ruthenium(II) (named E322) has been synthesized for use in dyesensitized solar cells (DSCs). Higher extinction coefficient and a broader absorption compared to the standard Ru-dye, N719, were aimed. DSCs were fabricated with E322, and the efficiency was 0.12% initially. (4.06% for N719, as reference). The efficiency was enhanced to 1.83% by exposing the cell under simulated sunlight containing UV-irradiation at short-circuit condition. The reasons of this enhancement are (1) enhanceing electron injection from sensitizer to TiO2 following a shift toward positive potentials of the conduction band of TiO2 by the adsorption of protons or cations from the sensitizer, or from the redox electrolyte and (2) improving the regeneration reaction of the oxidized dye by the redox electrolyte by the dissolution of aggregated dye from the surface of TiO2 following the treatment.

  • 21. Wiberg, Joanna
    et al.
    Marinado, Tannia
    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), Centra, Molekylär elektronik, CMD.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Albinsson, Bo
    Distance and Driving Force Dependencies of Electron Injection and Recombination Dynamics in Organic Dye-Sensitized Solar Cells2010Inngår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 114, nr 45, s. 14358-14363Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of dyes based on a triphenylamine donor and a rhodanine acetic acid anchor/acceptor for solar cell application has been studied with regards to electron injection and recombination kinetics using femtosecond transient absorption The series contains three dyes, with estimated electron transfer distances ranging from 17 2 to 11 0 angstrom and which have shown significant differences in energy conversion efficiencies The injection and recombination kinetics were studied in the NIR region where electrons in the conduction band of the TiO2 are suggested to absorb For all dyes, the injection rate is larger than (200 fs)(-1) which implicates a quantitative injection efficiency Surprisingly, the subsequent recombination reaction has a rate that increases with increasing linker length On the other hand, this behavior is consistent with the concomitant decrease in driving force for this series of dyes Moreover, the lifetimes show exponential distance dependence when corrected for driving force and reorganization energy, which indicates a superexchange interaction between the electrons in TiO2 and the radical cations of the dyes A dependence on probe wavelength of the attenuation factor was found giving a beta value of 0 38 angstrom(-1) at 940 nm and 0 49 angstrom(-1) at 1040 nm The difference is suggested to be due to the difference in electronic coupling between fully separated dye cations and injected electrons versus geminate electron-hole pairs Addition of tert butylpyridine, which from previous work is known to give a substantial drop in the IPCE values for the studied dyes, was found to decrease the amount of long-lived electrons in the TiO2 without affecting the injection rate

  • 22. Wiberg, Joanna
    et al.
    Marinado, Tannia
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi.
    Hagberg, Daniel P.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Hagfeldt, Anders
    KTH, Skolan för kemivetenskap (CHE), Kemi, Oorganisk kemi.
    Albinsson, Bo
    Effect of Anchoring Group on Electron Injection and Recombination Dynamics in Organic Dye-Sensitized Solar Cells2009Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, nr 9, s. 3881-3886Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the field of dye-sensitized solar cells, the number of different sensitizing dyes is increasing rapidly. To produce low-cost dyes, much work is being directed toward synthesizing all-organic, ruthenium-free dyes with high extinction coefficients and broad absorption bands with large solar spectrum overlap. One of the best dyes, the polyene-diphenylaniline dye D5L2A1, has a rather blue absorption with an IPCE onset at around 650 nm, but it still has an energy conversion efficiency of almost 6%. To increase the overlap with the solar spectrum, the cyanoacrylic acid anchoring group was changed to rhodanine-3-acetic acid in complex D5L2A3. This gave an IPCE onset at around 750 nm, but unfortunately, it also decreased the overall efficiency to a modest 1.7%. By femtosecond transient absorption, we show that the electron injections into TiO2 for the two dyes are ultrafast and indistinguishable with our time resolution (< 200 fs). However, charge recombination is also ultrafast, with different fractions of a ca. 500-fs component for the two dyes. Yet, the fraction of the faster decay component is larger for D5L2A3 than for D5L2A1. Here, we provide an interpretation of the implications of changing anchoring group. We believe that a lack of electron density oil the binding oxygens of the D5L2A3 LUMO, due to the rhodanine group, promotes a higher probability for electron injection to short-lived surface trap states compared to the situation for the fully conjugated D5L2A1.

1 - 22 of 22
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