Lisa J. Harlow

The goal of my research is to explore new, inexpensive materials that address issues with current efficient dye-sensitized solar cells (DSSCs). Many of the components used in the highest efficiency cells are costly, produce undesirable side products, or are not stable for long periods of time.

I have developed a reproducible solar cell fabrication method, providing a baseline to compare the changes we make to the solar cell. Our group is synthesizing and studying new iron (II) compounds for use as dyes in DSSCs. Iron is about eight magnitudes more abundant than ruthenium, the most efficient transition metal used for dyes. I am looking into new redox couples and semiconductor materials for incorporating these iron compounds into our solar cells.

I also have been working to reduce platinum loading to the counter electrode by introducing a new design: platinum nanoclusters suspended on a layer of graphene sheet developed by Prof. Larry Drzal’s group in Materials Science. The nanoclusters provide for a controllable decrease in Pt loading while increasing the Pt surface area.

We have also begun to look into solid-state electrolytes in collaboration with Prof. Greg Baker’s group in Chemistry, for use in DSSCs. One of the predominant problems of the solvent-based electrolyte is the volatility and its inability to be stable at higher temperatures that a solar cell will need to withstand. We are examining electrolytes that are not solvent based, rather ionic liquid or polymer-based.

Our group (also Baker and Drzal groups) is also working with Prof. Promislow and Prof. Christlieb from the Math Department to use modeling to (just to name a few) help understand the processes in our solar cells that I fabricate from the standard and new electrolyte/counter electrode materials, also hopefully anticipate the effects new materials will have to solar cell performance.

In addition to solar cell efficiencies, I will be looking into the rates of electron transfer and how changes to the cell affect these rates using voltage decay experiments, electrochemical impedance spectroscopy and time-resolved nanosecond spectroscopy on fully functioning cells.