An international team of scientists has demonstrated a breakthrough in the design and function of nanoparticles that could make solar panels more efficient by converting light usually missed by solar cells into usable energy.
The team, led by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), demonstrated how coating tiny particles with organic dyes greatly enhances their ability to capture near-infrared light and to reemit the light in the visible light spectrum, which could also be useful for biological imaging.
Once they understood the mechanism that enables the dyes on nanoparticles to function as antennas to gather a broad range of light, they successfully reengineered the nanoparticles to further amplify the particles’ light-converting properties. Their study was published online April 23 in Nature Photonics.
“These organic dyes capture broad swaths of near-infrared light,” said Bruce Cohen, a scientist at Berkeley Lab’s Molecular Foundry who helped to lead the study along with Molecular Foundry scientists P. James Schuck (now at Columbia University), and Emory Chan. The Molecular Foundry is a nanoscience research center.
“Since the near-infrared wavelengths of light are often unused in solar technologies that focus on visible light,” Cohen added, “and these dye-sensitized nanoparticles efficiently convert near-infrared light to visible light, they raise the possibility of capturing a good portion of the solar spectrum that otherwise goes to waste, and integrating it into existing solar technologies.”
Researchers found that the dye itself amplifies the brightness of the reemitted light about 33,000-fold, and its interaction with the nanoparticles increases its efficiency in converting light by about 100 times.
Image caption: An erbium atom (red) in a nanocrystal emits visible, green light via a process known as upconversion that could lead to the development of improved solar cells that capture some previously missed solar energy. Scientists discovered that coating the particles with dyes (blue and purple molecules at right) can greatly enhance this light-converting property. (Credit: Berkeley Lab)