Randall Ellingson

Randall Ellingson is a Professor of Physics and the Wright Center for Photovoltaics Innovation and Commercialization (PVIC) Endowed Chair at the University of Toledo, where he leads research in advanced photovoltaic materials and devices. He is affiliated with the Department of Physics and Astronomy within the College of Natural Sciences and Mathematics.

• Ph.D. in Applied Physics, Cornell University (1994)
• Bachelor's degree, Carleton College (1987)

Ellingson's research focuses on the development, characterization, and application of novel materials for improved photovoltaic performance. His group specializes in understanding energy loss mechanisms in nanoscale light absorbers and advancing assembly methods using colloidal semiconductor nanocrystals for thin-film solar cells. The Ellingson Group has made significant contributions to iron chalcogenides research, particularly iron pyrite nanocrystals (FeS2), and their application as back contacts in CdTe solar cells. They employ advanced optical spectroscopy techniques including time-resolved photoluminescence and pump-probe (transient absorption) to investigate charge carrier dynamics and exciton transport processes in semiconductor thin films.

Analysis of Ellingson's recent publications (2023-2025) reveals a strong focus on high-efficiency tandem solar cells, particularly perovskite-CdSeTe configurations pushing toward 30% efficiency. His work also emphasizes defect engineering in perovskite materials, doping strategies for CdTe-based devices, and novel processing techniques for scalable manufacturing. The research spans fundamental charge carrier dynamics to practical device implementation, with significant contributions to both thin-film and emerging photovoltaic technologies.

• Wright Center for Photovoltaics Innovation and Commercialization (PVIC) Endowed Chair

Dr. Ellingson spent 14 years at the National Renewable Energy Laboratory (NREL) working with Arthur Nozik, where he contributed to experimental evidence for multiple exciton generation in colloidal semiconductor quantum dots. Since joining the University of Toledo faculty in 2008, he has established a productive research program that bridges fundamental materials science with practical photovoltaic applications. His group has secured significant research funding and collaborates extensively with national laboratories and industry partners in the solar energy sector.

The Ellingson Group maintains state-of-the-art facilities for nanomaterials synthesis, thin-film deposition, and advanced optical characterization. They have developed specialized capabilities in colloidal nanocrystal synthesis, device fabrication for various photovoltaic architectures, and time-resolved spectroscopy for studying ultrafast charge carrier processes. The group actively collaborates with other research teams at the University of Toledo and national laboratories to advance photovoltaic technology.