title: Reactive self-tracking solar concentrators: concept, design, and initial materials characterization.
abstract: 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.
authors.affiliation: Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093, USA. kabaker@ucsd.edu
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Baker
authors.forename: Jason H
authors.initials: JH
authors.lastname: Karp
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Tremblay
authors.forename: Justin M
authors.initials: JM
authors.lastname: Hallas
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Ford