Heeger Lecture: Mike McGehee - Reflections On My Time At UCSB


Tuesday, June 11, 2024 - 2:00am


Elings Hall 1601


A Journey to Perovskite Tandem Solar Cells and Windows With Adjustable Tinting

I had an amazing experience in the 1990s doing research with Alan Heeger at a time when polymer LEDs, solar cells, and transistors were emerging. I also took classes from and attended seminars with some of the best professors in the history of materials science. I will share some of the lessons they taught me that have enabled my classmates and me to have special careers.

Metal halide perovskite semiconductors have remarkable properties for solar cells, including band gap tunability and defect tolerance, that have enabled the fabrication of perovskite-silicon tandems with 33.9% power conversion efficiency. Tandems can easily be 50% more efficient than silicon solar cells alone and could revolutionize an industry that is transforming the way humanity obtains energy. The design of these tandems and efforts to make them stable under light and heat as well as mechanically durable will be addressed.

Windows with adjustable tinting not only reduce glare without blocking views but can also reduce energy use for lighting, heating, and cooling by 20%. Decades of research in electrochromic materials have not yet resulted in windows that are color-neutral, sufficiently durable, and cost-effective. A new approach based on reversible metal electrodeposition will be presented. RME windows are color neutral, have superb dynamic range, and are inexpensive at scale. Tynt Technologies is commercializing this device, which could be thought of as a battery that is transparent in one of its states.

Professor Michael McGehee is the James M & Catherine Patten Chair in Chemical Engineering at the University of Colorado and Fellow of the Renewable & Sustainable Energy Institute (RASEI). He holds an AB from Princeton University and PhD from the University of California at Santa Barbara.