Leaf-inspired luminescent solar concentrator based on two-stage photoconversion

Area of Science:

• Optoelectronics
• Materials Science
• Renewable Energy

Background:

• Luminescent solar concentrators (LSCs) offer a promising avenue for solar energy harvesting.
• Enhancing the geometrical gain of LSCs is crucial for improving their efficiency and practical application.

Purpose of the Study:

• To investigate a new LSC design that drastically increases geometrical gain.
• To analyze the photon conversion and transport mechanisms within the proposed LSC structure.
• To quantify the performance of the developed LSC devices using experimental measurements.

Main Methods:

• Fabrication of LSC devices using a luminescent plate and a luminescent fiber with an air gap.
• Experimental setup involving laser excitation of a single spot on the plate.
• Measurement of photoluminescence (PL) photon conversion and waveguide efficiency.
• Assembly of 2 mm-thick, 50 mm-square and 50 mm-diameter circular devices with off-the-shelf components.

Main Results:

• Geometrical gain exceeding 1000 was achieved in experimental devices.
• The probability of a first PL photon resulting in a second PL photon reaching the PV cell was approximately 0.01.
• The fiber effectively guides optical power, analogous to nutrient transport in plant veins.

Conclusions:

• The proposed LSC design significantly enhances geometrical gain through a dual-stage luminescence and fiber-waveguiding approach.
• Further increases in geometrical gain are possible by connecting multiple small-area devices to a single photovoltaic cell.
• The design minimizes photon loss during waveguiding, paving the way for more efficient solar energy concentration.