Nanotechnology Could Increase Efficiency of Solar Panels

DURHAM, N.C. — New research suggests microscopic technology could help increase the efficiency of solar panels in the not-too-distant future. David Smith, a scientist at Duke University in Durham, N.C., and his team developed a metamaterial that has the unique property of maximizing the absorption of solar rays. A metamaterial is a substance that isn’t found in nature but is usually created by taking the blueprint for a previously existing element and altering it to create a new material with different properties.

This entire project was done on a very tiny microscopic level, using nanotechnology, which involves manipulating matter on the atomic or molecular scale. Essentially, our understanding of physics tells us that objects on the atomic and subatomic scale often behave very differently than objects we can perceive in our day-to-day lives.

Though finding out just why this is the case and exactly how our large-scale world interacts with the strange universe of atoms and quarks is a seemingly never-ending quest for physicists, they are finding more ways to take advantage of the differences over time.

Smith and his team mounted a microscopic piece of gold on top of a tiny sheet of glass and dipped them into two organic chemicals to make a uniform sheet on top of the gold. They then placed tiny cubes made of silver on top of the sheet. Because of their relative properties, the electrons in the silver cubes and the gold sheet react in a similar way when light hits one of the cubes. The electrons in both materials basically vibrate in unison, which causes the light to be pulled in between them, where it gets trapped in the organic sheet. The gold and silver work together to create a vacuum effect that makes sure the most possible light is pulled into the area, and the sheet works like fly paper, grabbing the light and holding it.

Using this strange microscopic phenomenon as a model, scientists can alter the thickness of the chemical sheet, which will change what kinds of light it will absorb. The silver cubes and gold layer will do their part either way; it’s just a question of what wavelength of light you want to trap. If you apply this technology to solar arrays, you can increase the amount of light that gets absorbed by the panels, giving you more energy.

Different solutions for increasing the absorption of light through nanotechnology have been achieved in the past, but most of the solutions require large amounts of money, time and resources to produce, making them unrealistic for commercial applications. Most of the previous solutions have involved arranging materials in very precise patterns on a very small level, which can be painstaking work. However, this new method allows scientists to sprinkle the nanocubes randomly on the sheet.

There is still work to be done. Scientists are looking for different materials to make the absorptive sheet out of, and they need to make the individual cubes more uniform in size; but they seem to believe this idea brings us much closer to creating a cost-effective solution for increasing the efficiency of solar panels and other devices in the future.