Photoelectrochemical cells convert sunlight into electricity, but their light-absorbing dyes, called chromophores, eventually degrade because of sunlight exposure. For plant cells, the degradation of chromophores isn't a big deal - they simply self-regenerate.
Now, Purdue researchers are in the early stages of creating a solar cell that self-repairs in a way that is similar to a plant's natural photosynthetic systems. Single-wall carbon nanotubes, anchored to strands of DNA, act as the "molecular wires" in the light harvesting cells. The DNA is engineered to have specific nucleotides that recognize chromophores and attach to them. Photo-damaged chromophores then may be removed by using chemical processes or by adding new DNA strands with different nucleotide sequences.
The work looks very interesting and could ultimately lead to a photoelectrochemical cell that operates at full capacity indefinitely.