Dr. Mahendra K. Sunkara
Department of Chemical Engineering
University of Louisville
Louisville, KY 40292
Phone: 502-852-1558
E-mail: mahendra@louisville.edu
Photoelectrochemical solar cells are considered as fourth generation solar cell technology for converting solar light into electricity. These PEC cells utilize nanostructured materials and can potentially be very cost effective and scaleable for solar energy farming. However, currently used nanostructured materials suffer from high recombination losses resulting in the low efficiencies, irreproducibility and unstable performance.
On the other hand, one dimensional semiconductor morphologies potentially provide several advantages for both dye and QDOT sensitized solar cells, including faster charge transport, faster charger injection kinetics and low recombination rates. Furthermore, they offer a unique platform for designing hybrid architectures while combining with nanoparticles of other semiconductor materials. In our recent work, we showed that electron transport through the 3-D branched nanowires is much faster than the nanowire films.
In this project, we are propose a number of nanowire based architectures for improving fundamental processes taking place within PEC solar cells: charge separation, charge transport and redox kinetics. Some of these nanowire based architectures include: (a) three-dimensional NW “tree” structures; (b) metal oxide, vertical NW arrays on metallic substrates; (c) Highly interconnected NW based powders; and (d) Nanowires coated with nanoparticles. In all of these studies, our goal is to understand the fundamental processes taking place within these PEC cells which will allow us to design a new type of PEC cells for efficient conversion of solar light to electricity. The proposed femto-second transient absorption spectroscopy facility (H. Rypkema) will be crucial in understanding the fundamental differences within the above sets of materials for energy conversion applications using photoelectrochemical cells.
mehanna@engr.uky.edu