Dye Sensitized Solar Cells

New insight into the regeneration kinetics of organic dye sensitised solar cells

by Stefano Martiniani

Stefano Martiniani ,  Assaf Y. Anderson ,  ChunHung Law ,  Brian C. O'Regan and Claudia Barolo
Chem. Commun., 2012, 48, 2406-2408
DOI: 10.1039/C2CC17100G

The order of regeneration for DSCs based on two organic dyes has been investigated by transient absorption... more The order of regeneration for DSCs based on two organic dyes has been investigated by transient absorption spectroscopy on devices under operating conditions and determined to be 2nd order in iodide. The results shed light on the mechanism and limits to the regeneration rate relative to oxidation potential.

Synthesis and Characterization of Triazolium Iodide Ionic Liquid Electrolyte for Dye Sensitized Solar Cells

by Sergio Granados

Imidazolium iodide compounds have been utilized in the electrolytes for dye sensitized solar cells (DSSC). Most of the... more Imidazolium iodide compounds have been utilized in the electrolytes for dye sensitized solar cells (DSSC). Most of the investigations with these compounds focus on the formulation of eutectic mixtures that promote efficient dissociation and diffusion of the iodide and triiodide species. Facile alternative synthetic approaches such as click chemistry (Huisgen 3+2 dipolar cycloaddition reaction) can be utilized to broaden the scope of electrochemically stable promising materials for novel electrolyte systems. Here, we report the first example of a triazolium functionalized cyclic siloxane that can be used as an electrolyte component in solvent-based DSSCs. The devices fabricated with this new triazolium salt in the electrolyte yielded short circuit current densities (26 mA/cm2), as well as power conversion efficiencies of 8%, these values are comparable to those obtained for imidazolium salt analogues.

Electrospray-assisted characterization and deposition of chlorosomes to fabricate a light-harvesting biomimetic device

by Luis Modesto-Lopez

Co-authored with Elijah J. Thimsen, Aaron M. Collins, Robert E. Blankenship, and Pratim Biswas. Energy and Environmental Science, 2010

Photosynthesis is an efficient process by which solar energy is converted into chemical energy. Green photosynthetic... more Photosynthesis is an efficient process by which solar energy is converted into chemical energy. Green photosynthetic bacteria such as Chloroflexus aurantiacus have supramolecular antenna complexes called chlorosomes attached to their cytoplasmic membrane that increase the cross section for light absorption even in low-light conditions. Self-assembled bacteriochlorophyll pigments in the chlorosome interior play a key role in the efficient transfer and funneling of the harvested energy. In this work it was demonstrated that chlorosomes can be rapidly and precisely size-characterized online in real time using an electrospray-assisted mobility-based technique. Chlorosomes were electrospray-deposited onto TiO2 nanostructured films with columnar morphology to fabricate a novel biomimetic device to overcome the solvent compatibility issues associated with biological particles and synthetic dyes. The assembled unit retained the viability of the chlorosomes, and the harvesting of sunlight over a broader range of wavelengths was demonstrated. It was shown that the presence of chlorosomes in the biomimetic device had a 30-fold increase in photocurrent.

Functionalized Graphene as a Catalytic Counter Electrode in Dye Sensitized Solar Cells

by Christian Punckt

J. D. Roy-Mayhew, D. J. Bozym, C. Punckt, I. A. Aksay
ACS Nano 4 (2010) 6203

When applied on the counter electrode of a dye-sensitized solar cell, functionalized graphene sheets with... more When applied on the counter electrode of a dye-sensitized solar cell, functionalized graphene sheets with oxygen-containing sites perform comparably to platinum (conversion efficiencies of 5.0 and 5.5%, respectively, at 100 mW/cm² AM1.5G simulated light). To interpret the catalytic activity of functionalized graphene sheets toward the reduction of triiodide, we propose a new electrochemical impedance spectroscopy equivalent circuit that matches the observed spectra features to the appropriate phenomena. Using cyclic voltammetry, we also show that tuning our material by increasing the amount of oxygen-containing functional groups can improve its apparent catalytic activity. Furthermore, we demonstrate that a functionalized graphene sheet based ink can serve as a catalytic, flexible, electrically conductive counter electrode material.