Highly efficient large-area colourless luminescent solar concentrators using heavy-metal-free colloidal quantum dots
Francesco Meinardi1, Hunter McDaniel2,3, Francesco Carulli1
1Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, via Cozzi 55, Milano I-20125, Italy.
Nature Nanotechnology
|August 25, 2015
Summary
New quantum dots in luminescent solar concentrators enable efficient, colorless photovoltaic windows. These eco-friendly solar devices reduce energy loss and improve spectral coverage for future net-zero buildings.
Area of Science:
- Materials Science
- Renewable Energy
- Nanotechnology
Background:
- Luminescent solar concentrators (LSCs) are key for net-zero buildings, acting as semitransparent photovoltaic windows.
- Colloidal quantum dots (QDs) offer tunable properties for LSCs but often suffer from spectral limitations and reabsorption losses.
- Existing QDs can cause coloration and limited light harvesting, hindering architectural integration.
Purpose of the Study:
- To develop large-area, non-toxic quantum dot-based LSCs with enhanced spectral coverage and reduced reabsorption.
- To create colorless photovoltaic windows suitable for architectural applications.
- To investigate the underlying photophysics of Stokes-shifted emission in these novel QDs.
Main Methods:
- Utilized ternary I-III-VI2 semiconductor quantum dots (CuInSexS2-x).
- Incorporated QDs into a photopolymerized poly(lauryl methacrylate) matrix.
- Fabricated freestanding, colorless LSC slabs.
- Performed optical power efficiency measurements and ultrafast spectroscopy.
Main Results:
- Achieved the first large-area, non-toxic QD-LSCs with reduced reabsorption and broader solar spectrum coverage.
- Developed freestanding, colorless slabs with no perceived color distortion, ideal for photovoltaic windows.
- Demonstrated an optical power efficiency of 3.2% due to suppressed reabsorption and high QD emission efficiencies.
- Spectroscopic studies indicated Stokes-shifted emission originates from a conduction-band electron and an intragap defect state.
Conclusions:
- Ternary I-III-VI2 QDs are highly promising for advanced LSC applications, overcoming limitations of previous materials.
- The developed QD-LSCs are well-suited for integration into building envelopes as efficient and aesthetically pleasing photovoltaic windows.
- The findings pave the way for more efficient and versatile solar energy harvesting in architectural designs.
