The primary research goal is to improve the performance of luminescent solar concentrators (LSCs) to where they become commercially viable. A LSC is a thin, flat plate of highly fluorescent material that uses total internal reflection to concentrate light at its edges where it is converted to electricity by semiconductor solar cells. The main advantage of the LSC is its cost. It is a cheap, non-directional, area collector of light focusing 74% of the photons it absorbs down to a very small area of expensive semiconductor material. Results from our previous grant illustrate that LSCs made with multiple dyes that form an excitation energy transfer network convert significantly more sunlight into electricity than a single-dye LSC. The dye networks are constructed to maximize absorption and minimize losses associated with the reabsorption of emission. The focus of this proposal is to decrease photodegradation such that a LSC has at least 50% of its initial maximum output after 5 years of field use Photodegradation is a major limit to the commercialization of LSCs. The causes of photodegradation for different fluorescent materials will be identified, such as, dependence on the wavelength of excitation (particularly that of ultraviolet light), oxygen, temperature, solvent used, and the state of the polymer. A variety of solutions will be tried depending on the causes identified. Novel solutions that will be explored include the use of fluorescent quantum dots and enhancing fluorescence quantum yield and photostability through electrodynamics interactions between a fluorescent material and metal. Work will also continue on developing and testing new multiple-dye LSCs to further improve their performance through increased absorption of sunlight.
Intellectual merit- This work will significantly enhance our understanding of the causes and solutions for photodegradation of fluorescent materials not only for use in LSCs but also in many other applications, such as, light-emitting diodes, solid dye lasers, fluorescent probes and for dyes in general. The feasibility of application of quantum dots and metal enhanced fluorescence will be experimentally tested. Broader impacts- Undergraduates will receive valuable research training on an interdisciplinary project and actively participate in its dissemination. We are proposing to broaden our base of collaborations during this grant period. The society will benefit from advances in solar energy collection.
