The design exploits the unusual electrical properties of structures called single-wall carbon nanotubes, using them as "molecular wires in light harvesting cells," said Choi, whose research group is based at the Birck Nanotechnology and Bindley Bioscience centers at Purdue's Discovery Park.
Generally, the material works in much the same way as plants do. In a photochemical cell, a light absorbing dye, called "chromophore" degrades, much like the chlorophyll molecule in plant leaf cells.
The problem with normal solar cells is that they degrade over time. This new technology overcomes that problem in the same way that plants do: by continuously replacing the broken down molecules. In plants this happens approximately once every hour.
This design theoretically allows for indefinite use of a solar cell, as along as new chromophores are added.
The design works by using DNA strands and carbon nanotubes. DNA is used for its ability to sponatneously assemble in a structured way, and the carbon nanotubes are used as a backbone for the DNA to attach to.
|Diagram illustrating the principle behind how electricity is generated. hv stands for light, while e- stands for electricity/electrons being produced. (Credit: http://spie.org/)|
Although the process is only in research stage and still far away from being used on an industrial stage, it shows promise, as most initial hurdles have already been overcome.