Change search
Link to record
Permanent link

Direct link
BETA
Svensson, Per H.
Publications (7 of 7) Show all publications
Gao, J., Yang, W., El-Zohry, A. M., Prajapati, G. K., Fang, Y., Dai, J., . . . Kloo, L. (2019). Light-induced electrolyte improvement in cobalt tris(bipyridine)-mediated dye-sensitized solar cells. Journal of Materials Chemistry A, 7(33), 19495-19505
Open this publication in new window or tab >>Light-induced electrolyte improvement in cobalt tris(bipyridine)-mediated dye-sensitized solar cells
Show others...
2019 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 33, p. 19495-19505Article in journal (Refereed) Published
Abstract [en]

Lithium-ion-free tris(2,2 '-bipyridine) Co(ii/iii)-mediated electrolytes have previously been proposed for long-term stable dye-sensitized solar cells (DSSCs). Such redox systems also offer an impressive DSSC performance improvement under light soaking exposure, manifested by an increase in photocurrent and fill factor without the expense of decreasing photovoltage. Kinetic studies show that charge transfer and ion diffusion at the electrode/electrolyte interface are improved due to the light exposure. Control experiments reveal that the light effect is unambiguously associated with electrolyte components, [Co(bpy)(3)](3+) and the Lewis-base additive tert-butylpyridine (TBP). Electrochemical and spectroscopic investigation of the [Co(bpy)(3)](3+)/TBP mixtures points out that the presence of TBP, which retards the electrolyte diffusion, however causes an irreversible redox reaction of [Co(bpy)(3)](3+) upon light exposure that improves the overall conductivity. This discovery not only provides a new strategy to mitigate the typical J(sc)-V-oc trade-off in Co(ii/iii)-mediated DSSCs but also highlights the importance of investigating the photochemistry of a photoelectrochemical system.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-259417 (URN)10.1039/c9ta07198a (DOI)000482139000027 ()2-s2.0-85071187004 (Scopus ID)
Note

QC 20190924

Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-09-24Bibliographically approved
Starkholm, A., Kloo, L. & Svensson, P. H. (2019). Polyiodide Hybrid Perovskites: A Strategy To Convert Intrinsic 2D Systems into 3D Photovoltaic Materials. ACS Applied Energy Materials, 2(1), 477-485
Open this publication in new window or tab >>Polyiodide Hybrid Perovskites: A Strategy To Convert Intrinsic 2D Systems into 3D Photovoltaic Materials
2019 (English)In: ACS Applied Energy Materials, ISSN 2574-0962, Vol. 2, no 1, p. 477-485Article in journal (Refereed) Published
Abstract [en]

Two new organic inorganic hybrid perovskite compounds, (Me3S)(2)Pb5I14*2I(2) (1) and (C8H11S)(2)Pb2I6*I-2 (2), have been synthesized and subsequently characterized in this study. The materials were synthesized from facile one-pot, one-step reactions of lead iodide, corresponding sulfide, methanol, iodine, and hydroiodic acid in the case of 2. Structural analysis reveals the presence of polyiodide entities in both compounds. Compound 1 contains triiodide anions, I-3(-), that are uniquely shared between the 2D inorganic slabs, forming a 3D network. Both 1 and 2 have I-2 molecules that are bridging the inorganic slabs through a structural motif that can be regarded as a tetraiodide anion, I-4(2-). Optical spectroscopy shows band gaps of 1.86 eV for 1 and 1.89 eV for 2. The optoelectronic properties were further investigated with band structure calculations. Single-crystal IV-characteristics of 1 show that the compound is photoactive confirming it as a promising photovoltaic candidate. Compound 1 highlights a novel strategy of designing 3D semiconducting hybrid materials by incorporating polyiodides to provide direct geometric and electronic connections between the semiconducting inorganic perovskite sheets.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
Keywords
organic inorganic hybrid materials, perovskites, polyiodide, solar cells, dimensionality, iodine
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-245958 (URN)10.1021/acsaem.8b01507 (DOI)000458706900060 ()
Note

QC 20190314

Available from: 2019-03-14 Created: 2019-03-14 Last updated: 2019-03-14Bibliographically approved
Ren, Y., Svensson, P. H. & Ramström, O. (2018). A Multicontrolled Enamine Configurational Switch Undergoing Dynamic Constitutional Exchange. Angewandte Chemie International Edition, 57(21), 6256-6260
Open this publication in new window or tab >>A Multicontrolled Enamine Configurational Switch Undergoing Dynamic Constitutional Exchange
2018 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 57, no 21, p. 6256-6260Article in journal (Refereed) Published
Abstract [en]

A multiresponsive enamine-based molecular switch is presented, in which forward/backward configurational rotation around the C=C bond could be precisely controlled by the addition of an acid/base or metal ions. Fluorescence turn-on/off effects and large Stokes shifts were observed while regulating the switching process with Cu-II. The enamine functionality furthermore enabled double dynamic regimes, in which configurational switching could operate in conjunction with constitutional enamine exchange of the rotor part. This behavior was used to construct a prototypical dynamic covalent switch system through enamine exchange with primary amines. The dynamic exchange process could be readily turned on/off by regulating the switch status with pH.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2018
Keywords
dynamic exchange, enamines, fluorescence, E/Z isomerization, molecular switches
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-230434 (URN)10.1002/anie.201802994 (DOI)000432710100049 ()29601656 (PubMedID)2-s2.0-85046299449 (Scopus ID)
Note

QC 20180615

Available from: 2018-06-15 Created: 2018-06-15 Last updated: 2018-10-30Bibliographically approved
Gao, J., Fischer, A. C., Svensson, P. H. & Kloo, L. (2017). Crystallography as Forensic Tool for Understanding Electrolyte Degradation in Dye-sensitized Solar Cells. CHEMISTRYSELECT, 2(4), 1675-1680
Open this publication in new window or tab >>Crystallography as Forensic Tool for Understanding Electrolyte Degradation in Dye-sensitized Solar Cells
2017 (English)In: CHEMISTRYSELECT, ISSN 2365-6549, Vol. 2, no 4, p. 1675-1680Article in journal (Refereed) Published
Abstract [en]

The precipitation of solid compounds from model electrolytes for liquid dye-sensitized solar cells has a story to tell regarding decomposition processes to be expected in such systems. Of course, the crystal lattice energy for a specific crystalline compounds plays a role in what compound that will eventually precipitate, but the compounds nevertheless serve as indicators for what type of processes that take place in the solar cell electrolytes upon ageing. From the compounds isolated in this study we learn that both ligand exchange processes, double-salt precipitation and oxidation are degradation processes that should not be overlooked when formulating efficient and stable electrolytes for this type of electrochemical system.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2017
Keywords
Crystallography, Dye-sensitized solar cells, Forensics
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-205131 (URN)10.1002/slct.201601756 (DOI)000395533900043 ()
Note

QC 20170517

Available from: 2017-05-17 Created: 2017-05-17 Last updated: 2017-05-17Bibliographically approved
Safdari, M., Phuyal, D., Philippe, B., Svensson, P. H., Butorin, S. M., Kvashnina, K. O., . . . Gardner, J. M. (2017). Impact of Synthetic Route on Structural and Physical Properties of Butyl-1,4-Diammonium Lead Iodide Semiconductors. Journal of Materials Chemistry A
Open this publication in new window or tab >>Impact of Synthetic Route on Structural and Physical Properties of Butyl-1,4-Diammonium Lead Iodide Semiconductors
Show others...
2017 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488Article in journal (Refereed) Accepted
Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
National Category
Natural Sciences Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-200279 (URN)
Note

QC 20170123

Available from: 2017-01-23 Created: 2017-01-23 Last updated: 2019-12-09Bibliographically approved
Cong, J., Kinschel, D., Daniel, Q., Safdari, M., Gabrielsson, E., Chen, H., . . . Kloo, L. (2016). Bis(1,1-bis(2-pyridyl)ethane)copper(i/II) as an efficient redox couple for liquid dye-sensitized solar cells. Journal of Materials Chemistry A, 4(38), 14550-14554
Open this publication in new window or tab >>Bis(1,1-bis(2-pyridyl)ethane)copper(i/II) as an efficient redox couple for liquid dye-sensitized solar cells
Show others...
2016 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 38, p. 14550-14554Article in journal (Refereed) Published
Abstract [en]

A new redox couple, [Cu(bpye)2]+/2+, has been synthesized, and applied in dye-sensitized solar cells (DSSCs). Overall efficiencies of 9.0% at 1 sun and 9.9% at 0.5 sun were obtained, which are considerably higher than those obtained for cells containing the reference redox couple, [Co(bpy)3]2+/3+. These results represent a record for copper-based complex redox systems in liquid DSSCs. Fast dye regeneration, sluggish recombination loss processes, faster electron self-exchange reactions and suitable redox potentials are the main reasons for the observed increase in efficiency. In particular, the main disadvantage of cobalt complex-based redox couples, charge-transport problems, appears to be resolved by a change to copper complex redox couples. The results make copper complex-based redox couples very promising for further development of highly efficient DSSCs.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016
Keywords
Cobalt compounds, Copper, Efficiency, Redox reactions, Solar cells, Cobalt complexes, Copper complexes, Dye regeneration, Electron self-exchange, Overall efficiency, Recombination loss, Redox potentials, Transport problems, Dye-sensitized solar cells
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-195535 (URN)10.1039/c6ta06782d (DOI)000385360300005 ()2-s2.0-84989315761 (Scopus ID)
Funder
Swedish Research Council Formas
Note

QC 20161115

Available from: 2016-11-15 Created: 2016-11-03 Last updated: 2019-12-09Bibliographically approved
Kloo, L., Rosdahl, J. & Svensson, P. H. (2002). On the Intra- and Intermolecular Bonding in Polyiodides. European Journal of Inorganic Chemistry (5), 1203-1209
Open this publication in new window or tab >>On the Intra- and Intermolecular Bonding in Polyiodides
2002 (English)In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 5, p. 1203-1209Article in journal (Refereed) Published
Abstract [en]

The nature of intra- and intermolecular interactions of poly-iodides has been investigated by means of quantum chemical methods and structural statistical data. In the region of "secondary bonds" the interaction is adequately described in terms of covalent bonding accompanied by dispersion. At greater distances the interaction is dominated by ion-quadrupole interactions between ionic and neutral iodine building blocks of the polyiodide structures.

Keywords
Bond theory, Iodine, Polyhalides
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-5105 (URN)10.1002/1099-0682(200205)2002:5<1203::AID-EJIC1203>3.0.CO;2-O (DOI)000175267800031 ()2-s2.0-0036238143 (Scopus ID)
Note

QC 20100924

Available from: 2005-05-15 Created: 2005-05-15 Last updated: 2019-11-15Bibliographically approved
Organisations

Search in DiVA

Show all publications