Through a cross between quantum physics and genetic engineering, researchers from the Massachusetts Institute of Technology (MIT) have managed to genetically enhance a virus which they claim can improve the efficiency of solar cells in transporting energy.
In photosynthesis, plants harness energy from the sun with almost 100 percent efficiency by making use of some of the principles in quantum physics called "quantum weirdness" while none of the energy is wasted, scientists say. Particles in plants are able to exist in more than one place at a time, which is an ability that surpasses even the best solar cells. This has led engineers in MIT to apply the principle in their attempt to create more efficient light-harvesting systems.
In a study published in the journal Nature Materials, Professor Seth Lloyd from the MIT, an expert on quantum theory and one of the researchers, explained that in photosynthesis, when a photon hits a receptor called a chromophore, a quantum particle called exciton is produced. An exciton transfers from one receptor to another until it reaches a reaction center to harness energy.
Researchers say that the path that an exciton takes may be inefficient and random, unless it takes multiple pathways and selects the best ones. This is possible if the particles are arranged with the right amount of distance in what quantum physicists call the "Quantum Goldilocks Effect."
Professor Angela Belcher, Lloyd's fellow researcher, has been developing a virus for years. The team then engineered Belcher's virus to bond with multiple synthetic chromophores or organic dyes, and they produced many different versions of the virus with different amounts of spaces between the synthetic chromophores. They chose the ones that performed most efficiently.
The result was that the exciton's speed had doubled and its distance had increased by 68 percent.
The two researchers had collaborated due to a chance meeting in Italy. Heechul Park and 14 more collaborators at MIT and in Italy also collaborated with them for this research. Lloyd has already published a mostly theoretical paper that demonstrated how photosynthesis efficiently transmits light through quantum principles. He said he wondered if it could be induced artificially.
"I had been talking about potential systems you could use to demonstrate this effect, and Angela said, 'We're already making those,'" said Lloyd. "We came up with design principles to redesign how the virus is capturing light, and get it to this quantum regime."
Researchers say that the study could possibly be applied in future developments of organic solar cells, organic light-emitting diodes, biosensors and in water splitting.
