University of Arizona professor of Engineering and Optical Sciences Raymond Kostuk is a principal contributor to a research team exploring a new way to increase the efficiency of photovoltaic (PV) panels that generate electricity directly from sunlight.
Collaborating with researchers from the University of Washington and the University of Denver with a grant from the Research Corporation for Science Advancement (RCSA), their project has the uber-geeky title of “Holographic Spectrum Splitting for Multijunction Organic Photovoltaics.”
The explanation of this work is actually quite simple, according to Kostuk.
“Photovoltaic cells that produce electricity from sunlight only convert a small percentage of incident sunlight into electricity,” he said. One way to make them more efficient is to use multiple junction. Most multijuntion cells today are designed with one junction grown on top of the next forming a tandem cell.
“Junctions are sensitive to specific colors in the spectrum of visible light,” he noted. Some junctions are sensitive to red light; some are sensitive to blue; others are sensitive to the other colors that make up sunlight.
“Some solar devices with stacked junctions already exist, but they are very expensive, which means they are used mostly on high concentration systems and orbiting satellites. Another problem is that it is difficult to match the interfaces on different multi junction devices which limits the range of materials that can be used,” Kostuk said.
OK, maybe not quite that simple, but there is the big bonus that could be the outcome of this research. The team’s hope is that the developed solar devices can be manufactured using carbon-based “organic” materials, which would be generally cheaper and easier to obtain.