PI Name: Noel C. Giebink
Proposal Number: 1508968
The sun represents the most abundant potential source of sustainable energy on earth. Solar cells that capture the sun's rays and convert this energy into electricity can potentially be improved through the science of photonics, which uses materials to mold the flow of light. The overall goal of this research is to combine photonics with traditional methods of light concentration, such as mirrors or lenses, to enhance the amount of sunlight delivered to a solar cell. The proposed research will use a combination of experimental and mathematical approaches to find the best combination of photonic and optic structures, and then test these new structures on solar cells to see if they improve performance. The educational and outreach activities built around this project include an exhibit targeted for middle and high school students at the USA Science and Engineering Festival held in Washington, DC. This exhibit will highlight the importance of luminescence in everyday life by through interactive activities that explain the science underlying fireflies, glow-in-the-dark paint, luminescent rocks, and similar curiosities.
The efficient capture of solar incidence is a major challenge in the development of new photovoltaic (PV) devices for the conversion of sunlight to electricity. The field of non-imaging optics addresses optimum geometric concentration via lenses or mirrors, and is most effective for collimated light. In contrast, luminescent concentrators (LCs) can intensify diffuse light incident from any direction by absorbing and re-emitting it into a waveguide. The overall goal of the proposed research is to combine luminescent concentration with non-imaging optics to leverage the advantages of both processes for more efficient capture of light for solar PV applications. Towards this end, nanoscale photonic structures will be engineered for highly directional luminescent emission and coupled with macroscale non-imaging optical surfaces to achieve increases in secondary geometric gain of light collection. The experimental and theoretical approach will combine electromagnetic simulation, ray tracing, conformal mapping, fabrication, and testing studies. Scalable design strategies for photonic materials will be developed to control spontaneous emission direction, and promising materials will be fabricated and tested using a range of organic fluorophores and ion-doped inorganic nanocrystals. Furthermore, discrete mathematical solutions for non-imaging optics will be developed for several directional emission profiles and validated using custom acrylic optic models. From this information, the formal analogy between light propagating in gradient refractive index media and in a constant index freeform waveguide will then be exploited to harness transformation optics as an alternative design tool, with the resulting waveguides fabricated through a process that enables scalable 3D printing of high quality, large area optical surfaces. Finally, luminescent concentrator waveguides with transfer-printed GaAs photovoltaics will be fabricated and tested to study how these structures impact solar PV performance. The optics and photonics themes of this research tie in closely with the planned educational activities and outreach.
|Effective start/end date||9/1/15 → 8/31/18|
- National Science Foundation: $306,910.00