U.S. Develops Self-Healing Solar Cells

According to a report from the American Physicists Organization Network on January 5 (Beijing time), US researchers are developing a new type of solar cell. Using carbon nanotubes, DNA, and other materials, the battery can function as a natural photosynthesis system in plants. Self repair to extend battery life and reduce manufacturing costs.

Photoelectrochemical cells convert sunlight into electricity and use electrically conductive electrolytes to transport electrons and create electrical current. One of the biggest drawbacks of traditional photoelectrochemical cells is that the dyes that absorb light are difficult to update. The new technology solves this problem by constantly replacing dyes damaged by photons with new dyes.

The new design utilizes the unusual electrical properties of single-walled carbon nanotubes. Carbon nanotubes can contain one layer to hundreds of graphite layers. Only one layer of graphite is called single-walled carbon nanotubes. Its diameter is about 1.5 nanometers, which is a very ideal nanochannel, an open single Wall carbon nanotubes can be used as "electric motors" and "generators." Scientists used single-walled carbon nanotubes as "molecular wires in light trapping cells" in experiments. The researchers explained that in new batteries, the main function of carbon nanotubes is to immobilize DNA fragments. Scientists also program DNA so that it has specific sequences that nucleotides possess, allowing them to recognize and attach dyes. Once the DNA recognizes the dye molecules, the system begins self-assembly and completes the renewal of the dye, just like the self-renewing process that is taking place within the plant at all times.

Innovative photoelectrochemical cells based on this idea can continue to work at full capacity as long as new dyes are continuously added to them. New or old replacements of dyes can be achieved by chemical processes or by adding new DNA fragments with different nucleotide sequences, knocking down old dye molecules, and then adding new dye molecules to them.

This technique of simulating the self-healing mechanism in nature has two key points: the molecular recognition and the stability of the system's continuous dissolution and recombination.

“Currently, we have used optical nanomaterials to create an artificial photosynthesis system that can capture and transform solar energy,” said Cui Zongxian, assistant professor of mechanical engineering at Purdue University who is leading the development of this new type of battery. For electrical energy, new methods can be industrialized in the future."

Other studies previously used biochromosomes that were extracted from bacteria to replace dyes, and Cui Zongxian stated that the use of natural color bodies is very difficult, it must be captured and isolated from bacteria, and its industrial production is also very expensive. Therefore, the Cui team did not use biochromosomes in the new test, but instead used artificial chromophores made from dye porphyrins.