Prof. Randy J. Ellingson
Professor, Department of Physics and Astronomy
Faculty Member, Wright Center for Photovoltaic Innovation and Commercialization (PVIC)

School for Solar and Advanced Renewable Energy, College of Natural Sciences and Mathematics
The University of Toledo
Toledo, OH 43606

B.A. Physics, Carleton College, 1987
Ph.D. Applied Physics, Cornell University, 1994
Randy J. Ellingson  

Research interests

  • Development, characterization, and application of new and previously-existing materials for improved photovoltaic (PV) performance. 
  • Understanding the dynamics and mechanisms of energy loss for electrons, holes, and excitons in nanoscale light absorbers and their assemblies, for application to PV energy conversion.
  • Advancing assembly methods to use solution-based colloidal semiconductor nanocrystals for thin-film solar cells.

Nanomaterials Synthesis, Optical Spectroscopies, and PV Materials Applications

The Ellingson Group focuses on synthetic capabilities, optical spectroscopies, and materials innovation for advancing photovoltaic and related technologies.  Recently, our group has synthesized high quality iron chalcogenides including iron pyrite nanocrystals (FeS2), and successfully applied these as a high-performance back contact to CdTe solar cells.   We also study ultrafast charge carrier processes in semiconductor thin films and PV devices, colloidal semiconductor nanocrystals and quantum dots, molecular absorbers such as single-wall carbon nanotubes (SWNTs), and nanostructured assemblies such as nanocrystal arrays formed through self-assembly routes. We utilize a variety of steady-state and time-resolved laser spectroscopy techniques such as time-resolved photoluminescence and pump-probe (transient absorption) to understand charge carrier dynamics as well as exciton transport processes.

The Ellingson Group is also interested in the assembly of colloidal semiconductor nanocrystals for use in simple solar cells with the potential for highly-efficient operation. A variety of inorganic semiconductors are of interest, especially those which utilize abundant, inexpensive elements such as Cu, Zn, Sn, S, Fe, and Si.