摘要 |
Optical devices and systems that provide high solar flux onto a multi-junction solar cell, or other target cell, to produce efficient electrical output. An optical device includes a primary focusing element, and a non-imaging secondary concentrator having an entry aperture and an exit aperture. The primary focus element is configured to focus light from a distant source onto the entry aperture of the secondary concentrator. The primary focusing element has an f-number that is greater than about 1, e.g., between 1 and 4 or greater. The device includes a solar cell located proximal to the exit aperture of the secondary concentrator. In certain aspects, the primary focusing element includes a Fresnel lens, a diffractive lens and/or a reflector. In certain aspects, a Fresnel lens used as the primary is flat, substantially square, curved and/or refractive. |