The concept of light-trapping has been played with for decades as a way of keeping a photon within the confines of a solar cell for longer periods of time, but there has always been upper limits of what energy the technique can wring from incoming light. By reducing the thickness of the cell to far less than the actual wavelength of light, though, appears to have a dramatic effect.
According to a paper published in Proceedings of the National Academy of Sciences, the ultrathin-film cells could improve on the macro-scale limits by as much as 12-fold.
"The amount of benefit of nanoscale confinement we have shown here really is surprising," said Zongfu Yu, a postdoctoral researcher at Stanford, in a press release. "Overcoming the conventional limit opens a new door to designing highly efficient solar cells."
Yu and colleagues sandwiched the solar film between layers that act to keep light trapped for longer periods of time, increasing the chances that a photon will be absorbed. The technology is probably a ways off from commercial deployment, but it joins a growing array of new materials and methods that might soon dramatically increase solar power's potential.
(Image via Stanford University)
