Michael McGehee smiling in front of wall
Associate Director • Professor • Fellow, RASEI

Office: SEEC C379
Mailbox: 027 UCB

Research Interests

The McGehee group is currently doing research on perovskite solar cells as well as dynamic windows that have adjustable tinting. This research builds on our prior investigations of organic light-emitting diodes and lasers, light extraction from LEDs, light trapping in solar cells, charge transport in organic semiconductors, nanopatterning, organic and dye-sensitized solar cells and semi-transparent electrodes based on meshes of carbon nanotubes or silver nanowires. The group is inspired to develop technology that can provide humanity with clean energy and solve environmental problems. Although all of our projects have a clear application and we interact closely with companies, we take a fundamental scientific approach that involves sophisticated characterization and advanced modeling.

Perovskite Solar Cells: Our goal is to demonstrate that it is possible to make perovskite tandem solar cells with 30% power conversion efficiency that will last for more than 25 years under typical operating conditions and can be manufactured cost-effectively. Starting in June 2018 we will be using the facilities at the National Renewable Energy Laboratory and collaborating closely with researchers there to accomplish this goal. We are adjusting the composition of A, B and X in the ABX3 formula to tune the bandgap and adjust the defect chemistry.  We make extensive use of x-ray diffraction, electron microscopy, XPS, spectroscopy, device characterization and device modeling to form a complete picture of how all the composition and processing affect the properties and in turn the performance of the solar cells.

Dynamic Windows: There is a tremendous opportunity to use windows with adjustable attempting to improve the energy efficiency of buildings and provide people with a more pleasing environment with optimized natural lighting. Although there are companies that produce electrochromic windows, the market has not yet exploded due to a combination of the windows not having a neutral color, switching too slowly and being too expensive. We are taking a different approach that is based on reversibly electroplating metal on transparent electrodes. Our glazing’s have a very neutral color and have excellent potential to be more cost-effective. We are developing methods for improving the conductivity of our transparent electrodes which should enable large windows to switch in under 30 seconds. This project involves electrochemistry, optics, the development of polymer electrolytes and long-term durability testing.