Published on August 15th, 2013 | by James Ayre1
Self-Healing Solar Cells — Vascular Channels Based On Plant Leaves Allow For Self-Healing In New Solar Cells
Self-healing solar cells — possessing “vascular” networks similar to those in plant leaves — have now been created by researchers from North Carolina State University. The new solar cells are able to effectively and inexpensively restore themselves to optimal functioning thanks to their possession of a “network of channels” which mimics the organic vascular systems found in most plants.
North Carolina State University explains:
In their new paper, the researchers show that creating solar cell devices with channels that mimic organic vascular systems can effectively reinvigorate solar cells whose performance deteriorates due to degradation by the sun’s ultraviolet rays. Solar cells that are based on organic systems hold the potential to be less expensive and more environmentally friendly than silicon-based solar cells, the current industry standard.
The nature-mimicking devices are a type of dye-sensitized solar cells (DSSCs), composed of a water-based gel core, electrodes, and inexpensive, light-sensitive, organic dye molecules that capture light and generate electric current. However, the dye molecules that get “excited” by the sun’s rays to produce electricity eventually degrade and lose efficiency, and thus need to be replenished to reboot the device’s effectiveness in harnessing the power of the sun.
“Organic material in DSSCs tends to degrade, so we looked to nature to solve the problem,” stated lead researcher Orlin Velev, who’s also the Invista Professor of Chemical and Biomolecular Engineering at NC State. “We considered how the branched network in a leaf maintains water and nutrient levels throughout the leaf. Our microchannel solar cell design works in a similar way. Photovoltaic cells rendered ineffective by high intensities of ultraviolet rays were regenerated by pumping fresh dye into the channels while cycling the exhausted dye out of the cell. This process restores the device’s effectiveness in producing electricity over multiple cycles.”
The researchers note that the selected design was tested against and compared with a variety of other designs, and that the branched channel networks that were most similar to the ones found in nature were shown to be the most effective.
The research was funded by the National Science Foundation and the US Department of Energy.
The new research was just published in the journal Scientific Reports.