West Virginia University graduate student Scott Cushing recently attended the American Physical Society Media Panel in Baltimore, Md., to present his ongoing research on harnessing the energy from the sun.
“Due to the looming energy crisis, great strides are being made to convert everything from the power of the wind to the power of the sun into energy in a renewable manner,” Cushing said. “With this renewable energy, we would no long be reliant on fossil fuels and their harmful emissions.”
Cushing’s research involves working with solar cells, devices that convert sunlight into electricity. The key part of a solar cell, a semiconductor, can absorb sunlight and output the energy as electrical power.
“Solar cells hold great promise for a green energy source in the future because they are operated purely by the power of the sun,” Cushing said. “However, current solar cells do not absorb the entire solar spectrum but only absorb a small percentage of it. This is why you see an entire roof covered in solar cells only to power half of a house’s electricity.”
Cushing’s research focuses on enhancing solar energy harvesting by using the properties of plasmons. A plasmon is a unique phenomenon that occurs when scientists make metal nanoparticles that are even smaller than the wavelength of light they are absorbing. A plasmon allows metal nanoparticles in the solar cell to absorb sunlight as if the metal nanoparticle were hundreds of times its physical size.
“It is as if the plasmon is a tiny antenna specifically tuned to absorb sunlight then give the energy to the solar celljust like the antenna on your car collects faint radio signals and gives it to your stereo to be output through your speakers,” Cushing explained.
These plasmons not only enhance solar cells, but also water splitting. Water splitting creates hydrogen from water to be used as fuel at a later time. This fuel could then be stored for later use and be used to fuel cars or to power houses.
“Both techniques of solar energy harvesting are inefficient at absorbing all of the sunlight that hits earth, but by putting these plasmonic antennas on the material, we can capture the lost light and increase the efficiency,” Cushing said.
“This discovery will help to make solar cells and water splitting a more commercially viable technology. We hope to continue this path of research to increase the level of efficiency to where it can compete with current non-renewable energy sources. The hope is that one day we can replace our dependence on fossil fuels with renewable energy sources that will not run out and will not negatively affect the environment.”
Cushing, a native of Charleston, W.Va., obtained his undergraduate degree through the Department of Physics at WVU and is continuing his graduate studies in physics as a Mountaineer. He hopes to one day become a professor to continue his research while teaching the next generation of scientists. Cushing is co-advised by Alan Bristow, Ph.D., of the Department of Physics and Nick Wu, Ph.D., of the Department of Mechanical and Aerospace Engineering. The work is done in collaboration with Jiangtian Li, a post doctor in Wu’s group.
This work was supported by the National Science Foundation and the Graduate Research Fellowship program.