Molecular Engineering and Sciences Seminar Series
Making smart windows smarter: symbiotic pairing of near-UV solar cells with electrochromic windows for visible light + heat management in architectural applications
Abstract: Energy use in residential and commercial buildings comprises about 40% of energy demand today and 30% of energy-related carbon emissions in the United States, with heating accounting for nearly twice the energy required for cooling and lighting combined. Increasing building energy efficiency will shave peak demands for electricity. In my talk, I will highlight our development of solar-powered, wireless electrochromic windows that can be integrated into windows to reduce electricity consumption and simultaneously increase occupant comfort [1]. The solar-powered electrochromic window comprises a polyelectrochromic conducting polymer that is optically transparent in its reduced state and dark blue in its oxidized state. Integration with a semitransparent organic solar cell provides onboard power to switch between its transparent and colored states. By designing and using materials that absorb exclusively in the ultra-violet and near-visible as the photoactive layers in our single-junction solar cells, the resulting devices exhibit open-circuit voltages > 1.4 V to directly drive switching of the electrochromic windows with high contrast. Importantly, the active layers of our devices are pinhole- and defect-free. Coupled with inherently low resistive power losses, the photocurrents are scalable with the footprint of solar cells while our devices retain high fill factors. We can thus tune device photovoltage per application needs through judicious selection of the donor/acceptor materials pair, and access the necessary photocurrents by fabricating arbitrarily large devices. Bio: 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 the creation of “smart” windows to increase building and energy efficiencies. Lynn received her BSE from the University of Pennsylvania and her PhD from Princeton University. She was on the chemical engineering faculty at the University of Texas at Austin before 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 foster collaborations 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 120 affiliated faculty members spanning 40 departments, centers and programs on campus, the Andlinger Center is developing solutions for our energy and environmental future. The author of over 160 publications, Lynn has delivered more than 200 invited and plenary lectures. She is a fellow of the American Physical Society and a Young Global Leader of the World Economic Forum. Her scholarly work has been recognized by 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. This weekly seminar brings together students, faculty and invited guests from various disciplines across campus to explore current trends in molecular engineering and nanotechnology. It is a forum for active interdisciplinary discussions. These talks are open to the public and attract a diverse audience of students and faculty. |