Solar Energy

Due to its potential to meet the entire global energy demand, solar energy has been widely investigated as an alternative to fossil fuels.  In photosynthesis, nature has developed a mechanism for using light from the sun to convert carbon dioxide into fuel in the form of sugars.  A key step in photosynthesis is the oxidation of water to oxygen, hydrogen ions, and electrons in the oxygen-evolving complex in photosystem II. 

2 H2O → O2 + 4 H+ + 4 e-

The solar energy research in the Schmuttenmaer group is part of a larger solar energy collaboration in the Chemistry Department at Yale.  Together with the Batista, Brudvig, and Crabtree groups, we are interested in developing a system to photochemically oxidize water using inexpensive and sustainable materials.  Specifically, we focus on dye-sensitized semiconductor nanoparticulate thin films which are similar to those used in dye-sensitized or Grätzel-type solar cells but which are adapted for the extra challenges that water oxidation presents.

In the Schmuttenmaer Lab, we use terahertz spectroscopy to elucidate the electron transfer processes between photoexcited dyes and semiconductor nanoparticles.  Using time-resolved terahertz spectroscopy (TRTS) as a non-contact electrical probe, we can determine conductivity on a sub-picosecond timescale in systems such as these that are traditionally difficult to analyze.