Researchers at Los Alamos National Laboratory in the USA are attempting to turn windows into transparent solar panels through the use of quantum dots.
Quantum dots are semiconductors with the ability to tightly confine electrons or holes in all three spatial dimensions and can be finely tuned. They are incredibly small, just around one-billionth of a meter across, or 10 to 50 atoms wide.
Conventional solar cells generally only convert certain wavelengths of light; which leads to heating and general inefficiency. If all the incoming light could first be converted to suitable wavelengths, efficiency could be raised dramatically.
The is where the quantum dots come into play and the properties of the difference in their size that makes them so useful A bigger quantum dot can process light on the red end of the spectrum, a smaller dot on the green-blue end.
The Los Alamos National Laboratory Center for Advanced Solar Photophysics researchers have developed a luminescent solar concentrator with appropriately tuned quantum dots dispersed throughout a clear plastic material, which forms a waveguide.
The quantum dots contained within absorb the sunlight and convert it to a wavelength best suited to a solar cell. This processed light is channeled toward the solar cells installed at its edges, which in turn generates electricity.
The quantum dots in the material have been created using copper, indium, selenium and sulfur. The finished product is totally transparent and with only a slight, neutral-colored tinting effect
” If this technology replaced all the glazing on the One World Trade Center building in New York City, the windows could power more than 350 apartments. How’s that for megascale impact from nanotechnology?” says Los Alamos National Laboratory’s Victor Klimov.
The Center for Advanced Solar Photophysics’ goal is to lay down practical foundations for third-generation solar energy technologies able to produce high conversion efficiencies using non-thermalized carriers, inexpensive scalable structures, and routine chemical fabrication processes.
Other solar window technology we’ve covered in the past includes an invention by Michigan State University scientists and more recently, the “accidental solar cell” that may also have applications for windows.