Researchers at North Carolina State University have developed a concept for an “artificial leaf” that generates solar energy, based on the same principles that occur in nature when plants draw energy from the sun. The new device is actually a flexible water-based gel combined with light-sensitive molecules. The molecules could be made synthetically, but the research team has used natural plant chlorophyll in the initial stages of the experiment, due to its potential for lowering costs and reducing the use of toxic materials in solar cells.
Solar Power, the Natural Way
When the gel-filled device is exposed to sunlight, the infused molecules react in a way that is similar to the reactions that occur in plants as chlorophyll converts solar energy into sugars. Electrodes in the device are coated with carbon nanotubes, carbon black or graphite, which are far less expensive than conventional platinum coatings. In terms of efficiency the device still has a long way to go, but the researchers foresee the potential for improvement by tweaking both the gel and the molecules. In addition, the researchers hope to replicate the self-regenerating mechanisms in plants. That leads to the possibility of low-cost installation and maintenance methods, as the solar gel could be “grown” on roofs and other surfaces.
Solar Energy and Chlorophyll
The focus on chlorophyll illustrates how the solar energy research field has expanded beyond silicon based solar cell technology, and this is just the tip of the iceberg. Some researchers are focusing on producing solar energy from phtalocyanines, which are common dyes that share the characteristics of chlorophyll. A team from Australia and Germany has also discovered an apparently new form of chlorophyll that can harvest light from more parts of the light spectrum, which could help in the development of new strains of algae for producing biofuel.
Image: Leaf by seeks2dream on flickr.com.