Basel Universität

Dye-sensitized solar cells

Our group focuses on the characterisation of dye-sensitized solar cells (DSCs) and their components. Our aim is to investigate the cells down to the nanoscale in order to understand how the fundamental processes influence the device performance. We apply standard device investigation techniques like IV-curve characterisation, quantum efficiency, open circuit voltage decay and charge extraction measurements. Combined with theory these experimental results are used to determine key characteristics like diffusion lengths or effective lifetimes of the electrons in the photo anode.

We apply standard device investigation techniques like IV-curve characterisation, quantum efficiency, open circuit voltage decay and charge extraction measurements. Combined with theory these experimental results are used to determine key characteristics like diffusion lengths or effective lifetimes of the electrons in the photo anode.
Furthermore, we investigate the different cell components (in particular the photo anode) with a set of microscopy methods. Our speciality is Kelvin probe force microscopy of the mesoporous titania films (stained and unstained). This techniques allows the determination of work function differences with a spatial resolution in the nanometer range and thus the evaluation of surface treatments especially the dye sensitization. For example band bending resp. band shifts due to surface dipole moments and the dye loading itself can be investigated. Other microscopy methods like scanning laser and scanning electron microscopy are applied as well, in order to assess the structure of the mesoporous titania film and the compact blocking layers.

We have collaborations with the group of E. Constable and C.Housecroft at the chemistry department and with DSM nutritional foods where we mainly focus on the investigation of DSCs with natural sensitizers (i.e carotenoic acids). Recently these cells reached a record conversion efficiency of 2%. The group of natural sensitizers is especially interesting for low cost devices with a short lifetime where the usage of rare materials makes no sense because of limited recycling possibilities.
To have more details: BjNano


Publications related to this research topic:

Porphyrins on Titania
Th. Glatzel R. Jöhr, A. Hinaut, R. Pawlak, A. Sadeghi, S. Goedecker, S. Decurtins, E. Meyer, and
Kyoto Workshop on Recent Progress in Advanced Scanning Probe Techniques, 2016-03-10, Kyoto, (Japan).
Modular synthesis of simple cycloruthenated complexes with state-of-the-art performance in p-type DSCs
F. Brunner, N. Marinakis, C. Wobill, M. Willgert, C. D. Ertl, T. Kosmalski, M. Neuburger, B. Bozic-Weber, Th. Glatzel, E. C. Constable, and C. E. Housecroft
J. Mater. Chem. C, 4, (2016), 9823-9833, pdf.
Interaction of metallo-carboxyphenyl porphyrins with rutile TiO2 (110)
R. Jöhr, A. Hinaut, R. Pawlak, A. Sadeghi, S. Goedecker, S. Decurtins, T. Glatzel, E. Meyer
18th International Conference on non contact Atomic Force Microscopy, 2015-09-10, Cassis, (France), Abstract (PDF).
Influence of carboxyl groups on the porphyrin morphology
L. Zajac, P. Olszowski, R. Jöhr, Th. Glatzel, E. Meyer, B. Such, M. Szymonski
8th International Workshop on Nanoscale Pattern Formation at Surfaces, 2015-07-14, Krakow, (Poland), Abstract (PDF).
Interaction of Metallo-Carboxyphenyl Porphyrins with Rutile and Anatase TiO2
R. Jöhr , A.Hinaut, R. Pawlak, A. Sadeghi, L. Zajac, B. Such, S. Goedecker, M. Szymonski, Th. Glatzel, E. Meyer
8th International Workshop on Nanoscale Pattern Formation at Surfaces, 2015-07-14, Krakow, (Poland), Abstract (PDF).
Impact of photocatalysis on carotenoic acid dye-sensitized solar cells
R. Jöhr, L. Zajac, G. Günzburger, H. Hug, B. Such, M. Szymonski, E. Meyer and Th. Glatzel
Hybrid Materials, 2, (1), (2015), 17-24, pdf.
Using Scanning Electrochemical Microscopy to Examine Copper(I) Sensitizers for Dye-Sensitized Solar Cells
C. J. Martin, B. Bozic-Weber, E. C. Constable, Th. Glatzel, C. E. Housecroft and I. A. Wright
J. Phys. Chem. C, 118, (2014), 16912-16918, pdf.
Development of scanning electrochemical microscopy (SECM) techniques for the optimization of dye sensitized solar cells
C. J. Martin, B. Bozic-Weber, E. C. Constable, Th. Glatzel, C. E. Housecroft and I. A. Wright
Electrochimica Acta, 119, (2014), 86-91, pdf.
Kelvin probe force microscopy of nanocrystalline TiO2 photoelectrodes
A. Henning, G. Guenzburger, R. Jöhr, Y. Rosenwaks, B. Bozic-Weber, C. E Housecroft, E. C Constable, Th. Glatzel, E. Meyer
Beilstein Journal of Nanotechnology, 4, (2013), (2013), 418-428, pdf.