Coffee available at 11:15
Transparent solar cells that exclusively harness UV photons can provide on-board power for electrochromic windows to regulate visible and infrared light transmission without competing for the same spectral irradiance. With more than 40% of national electricity consumption attributed to heating, cooling, and lighting in commercial and residential buildings, this solar cell technology can unlock new markets for such electrochromic windows, simultaneously rendering energy savings, reducing carbon emissions, and increasing occupant comfort. The ability to provide onboard power obviates the need for external wiring in such electrochromic windows, which should dramatically decrease installation costs and increase window operability. Starting with the design and synthesis of molecular chromophores possessing wide bandgaps, we recently constructed and tested such UV-absorbing solar cells, and demonstrated their utility in powering electrochromic windows. This technology was highlighted in the Wall Street Journal as “smart windows that can be sunglasses for [one’s] house.”
In this talk, I will highlight this self-powered smart window technology, focusing on the development of the UV-absorbing solar cells. The use of wide bandgap chromophores has allowed us to exclusively harvest near UV light, leaving visible light and infrared heat to be regulated by the electrochromic window. A necessary consequence of using wide bandgap chromophores is that our solar cells produce high-voltage, low-current power. Coupled with pinhole- and defect-free active layers, this inherently low-loss power production is scalable with the footprint of the solar cells. In our prototype, the energy that is produced by the solar cell in an hour exceeds more than ten times the energy that is required to power the electrochromic window over a 24-hour period. With a simple storage device that trickle charges the electrochromic window, light transmission can be regulated in the evenings and on cloudy days, independent of solar insolation.
Yueh-Lin (Lynn) Loo is the Theodora D. ’78 & William H. Walton III ’74 Professor in Engineering and Director of the Andlinger Center for Energy and the Environment at Princeton University.
In the Chemical & Biological Engineering Department, her research focuses on the processing and development of materials for low-cost, lightweight and flexible solar cells and circuits, the combination of which is being explored for a range of applications, including the creation of “smart” windows to increase building and energy efficiencies. More recently, Lynn’s research expanded into economic modeling of liquid fuel production from non-food biomass after her stint at NewWorld Capital Group, a private equity firm that invests in environmental opportunities.
Lynn received her BSE in Chemical Engineering and in Materials Science and Engineering from the University of Pennsylvania in 1996 and her PhD from Princeton University in 2001. She spent a year at Bell Laboratories, Lucent Technologies before joining the faculty in the Chemical Engineering Department at the University of Texas at Austin. She returned to Princeton University in 2007. As the Associate Director of External Partnerships at the Andlinger Center from 2011 to 2015, Lynn launched and led Princeton E-ffiliates Partnership to promote teacher-student-practitioner interactions and foster collaboration with the private sector. She served as Acting Vice Dean of the School of Engineering and Applied Science in the spring of 2016 and was appointed Director of the Andlinger Center in July 2016. With over 100 affiliated faculty members spanning science and engineering disciplines and humanities, the Andlinger Center is developing solutions to ensure our energy and environmental future.
The author of over 140 publications, Lynn has delivered more than 200 invited and plenary lectures globally and she serves on numerous international advisory boards of peer academic institutions, non-governmental organizations, journal publishers and private companies. She is a fellow of the American Physical Society, a Young Global Leader of the World Economic Forum and a Strategic Advisor for NewWorld Capital Group. Her scholarly work has been recognized by numerous accolades, including Sloan and Beckman Fellowships, the John H. Dillon Medal from the American Physical Society, the Peter and Edith O’Donnell Award in Engineering from the Texas Academy of Medicine, Science and Engineering, and the Alan P. Colburn Award from the American Institute of Chemical Engineers.
You can learn more about her and her research group at: http://princeton.edu/~loogroup, and about the Andlinger Center for Energy and the Environment at http://acee.princeton.edu.