More energy from sunlight strikes the Earth in one hour than all the energy consumed on the planet in a year.  Yet, this vast potential remains largely untapped due to the high cost of traditional, silicon-based solar cells. In this area of research, our

aim is to understand the complex interplay of electronic, structural, and optical effects that enable a material to convert sunlight into electricity efficiently.

This picture shows a cartoon of the of most basic mechanisms are operative in any device that convert photons to electrons.  Namely,

1. 1.photo-excitation of an electron
   

2. 2.thermalization of this excited electron/hole to conduction and valence band minima
   

3. 3.exciton formation and diffusion
   

4. 4.charge separation
   

5. 5.free carrier transport
   

6. 6.collection at metal contacts
   

In our work, different materials are studied with the aim of better understanding and ultimately improving one or more of these fundamental processes.  Because of the range of length and time scales and the complexity of the materials under consideration, a combination of computational approaches is employed, ranging from analytic models to classical force fields, and density functional theory to more accurate mand-body methods such as quantum Monte Carlo.

Below are links to descriptions of various solar cell projects currently underway in our group.