Schottky Solar Cells Based on Colloidal Nanocrystal Films: Searching for Enhanced Potocurrent

ChEMS Seminar

Featuring Matthew D. Law, Ph.D.
Assistant Professor, Chemistry
School of Physical Sciences, UC Irvine

Location:  Donald Bren Hall,  Room 1300

Free and open to the public

Solar cells based on films of electronically-coupled nanocrystals (NCs) sandwiched between two electrodes are excellent model systems for studying multi-exciton dynamics, charge transport, and junction formation in quantum dot solids. These devices are of interest for efficient, low-cost solar energy conversion because they can be processed in solution and may produce photocurrent that is significantly enhanced by multiple exciton generation (MEG). In this presentation, Law describes a simple, all-inorganic metal/NC/metal sandwich cell that produces a large short-circuit photocurrent (>21 mA cm-2) by way of a Schottky junction at the negative electrode. These devices demonstrate that large photocurrents can be collected from colloidal NC films without the need for sintering, superlattice order or separate phases for electron and hole transport. An optical model is used to determine the photon-to-electron conversion efficiency of photons absorbed by the NCs in order to test for MEG-enhanced photocurrent. Finally, Law will discuss recent transient absorption measurements of MEG in NC films, as well as his ongoing efforts to fabricate NC p-n junction solar cells with improved efficiency.

About the Speaker:
Matthew D. Law, Ph.D., is an assistant professor of chemistry at UC Irvine. He earned his Ph.D. in chemistry under the advisement of Peidong Yang, Ph.D., at U.C. Berkeley in 2005, and was a postdoctoral fellow with Arthur Nozik at the National Renewable Energy Laboratory in Golden, Colo., until the summer of 2008.