Fluorescent Optical Concentration of Uncollimated Sunlight

There is an urgent need to use solar energy to produce electricity, fuels and chemicals.

However, the highly diffuse nature of sunlight in angle, wavelength and space complicate its high-efficiency, low-cost and scalable conversion.

FOCUS will develop thin-films that concentrate sunlight in these three aspects, creating collimated, monochromatic, high-intensity beams that can provide advantages for photovoltaics and photocatalysis. The underlying concept is a radically different design for a luminescent solar concentrator (LSC).

Conventional LSCs use an emitter-doped plastic or glass sheet as a waveguide, concentrating direct and diffuse sunlight via total internal reflection of fluorescence.

The losses associated with reabsorption, emission into the waveguide escape cone and Stokes shift have limited LSC efficiency to 7%.

I will eliminate the waveguide completely and replace it with nanophotonic lenses, solving the longstanding problems with LSCs. The key challenges for successful implementation are addressed in three work packages.

Nanophotonic design (WP1) will give FOCUS foils that absorb broadband sunlight from all angles, funnel the excitons to lower bandgap nanoscale emitters and concentrate the collimated fluorescence outside of the film.

Material learning (WP2) and reciprocity-inspired photosynthesis will use the desired emission pattern to train a material to emit from self-optimized positions, leading to FOCUS foils that learn the desired optical output.

Ultrafast 3D nanoprinter (WP3) development will lead to a microscope that synthesizes emitters directly within a solid-state host, tracks their performance (quantum yield, angular emission pattern) in real-time and watches excited carriers relax into directionally emitting states.

My track record in nanophotonic solar cells and directional emission combined with my network of leading collaborators put me in an excellent position to achieve these goals.