Folds and Wrinkles to Improve Solar Cell Efficiency
Though interest in solar panels is greatest now, solar absorbers have existed longer than man. Every leaf on a tree is the product of hundreds of millions of years of experimentation to find the best way to capture photons. Researchers at Princeton University, Engineering School are borrowing from the design of leafs and have made incredible advances in plastic photoelectric cells.
Plastic solar panels work just like silicon solar panels do but instead of using silicon they use plastics, or polymers. While these organic materials can be made more cheaply than silicon and are more resilient, they are not as efficient as the semiconductor. The Princeton researchers appear to have found a way to close the efficiency gap between the two materials by putting folds and wrinkles on the surface.
Just as on leafs, these surface features act as waveguides to the captured light. When light strikes a leaf or the new solar panels, instead of being either absorbed or reflected, it can become trapped until the cell can absorb it. This allowed the cell to reach 10.6% efficiency, which is not necessarily spectacular but is getting to the 10-15% efficiency range believed to be needed for commercial development. However the solar cell has able to absorb long wavelength light six times better than most other cells.
Perhaps the greatest discovery of this research is that it is not limited to plastic solar cells. These surface features should improve the efficiency of any solar cell they are imprinted on.