Dresden 2017 – wissenschaftliches Programm
CPP 13.22: Poster
Montag, 20. März 2017, 18:30–21:00, P1A
Dye-Sensitized Solar Cells based on Low-Temperature Electrodeposited ZnO and Co(II/III) Redox Electrolyte — •Raffael Ruess1,2, Sebastian Haas1,2, Andreas Ringleb1,2, and Derck Schlettwein1,2 — 1Justus-Liebig-University Giessen, Institute of Applied Physics — 2Justus-Liebig-University Giessen, Laboratory for Materials Science (LaMa)
Emerging photovoltaics, such as dye-sensitized solar cells (DSSCs), have received great interest in the recent years because of quite high record efficiencies (<14.3%) and low energy payback times. The present work is focused on DSSCs based on electrodeposited, porous zinc oxide which allows low preparation temperatures to further reduce energy consumption of cell production and allows the preparation on flexible polymer substrates. To reduce voltage loss in the cell and thus improve the power conversion efficiency, the commonly used I−/I3− redox electrolyte in these DSSCs is replaced by a Co(II/III) redox couple. Recombination, electrolyte diffusion and electron transport in the DSSC devices are studied by impedance spectroscopy, intensity modulated photocurrent and photovoltage spectroscopy and charge extraction techniques. It was found that the interaction of the cobalt redox mediator with zinc oxide at the interface lowers the conduction band position of ZnO and, thus, leads to a lower open-circuit photovoltage. However, efficient dye regeneration can be achieved due to sufficient mass transport through the nanoporous system resulting in high photon-to-electron conversion efficiencies.