Fluorescent Optical Concentration of Uncollimated Sunlight

Introduction

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 complicates its high-efficiency, low-cost, and scalable conversion.

Project Overview

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 LSC Limitations

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
• Stokes shift

have limited LSC efficiency to 7%.

Proposed Solution

I will eliminate the waveguide completely and replace it with nanophotonic lenses, solving the longstanding problems with LSCs.

Work Packages

The key challenges for successful implementation are addressed in three work packages:

1. Nanophotonic Design (WP1): This 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.

2. Material Learning (WP2): 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.

3. 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.

Conclusion

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