Étendue limits angular acceptance of high-concentration photovoltaic systems and imposes precise two-axis mechanical tracking. We show how a planar micro-optic solar concentrator incorporating a waveguide cladding with a nonlinear optical response to sunlight can reduce mechanical tracking requirements. Optical system designs quantify the required response: a large, slow and localized increase in index of refraction. We describe one candidate materials system: a suspension of high index particles in a low index fluid combined with a localized space-charge field to increase particle density and average index. Preliminary experiments demonstrate an index change of aqueous polystyrene nanoparticles in response to a low voltage signal and imply larger responses with optimized nanofluidic materials.
Sophia Haussener, Silvan Suter, Etienne Boutin, Mahendra Patel
Stefaan De Wolf, Jakub Holovsky, Randall Ellingson, Xin Yu Chin
Jérôme François Sylvain Dujardin, Annelen Kahl