A research team at Lund University has used mirrors, placed only a few hundred nanometres apart, to use light more efficiently. The finding could eventually be useful for controlling solar energy conversion during photosynthesis, or other reactions driven by light.
Harnessing solar energy to capture greenhouse gases is extremely popular in scientific research. This is because the sunlight that hits Earth for one hour is almost equivalent to the total energy consumption of mankind for an entire year.
At the same time, our global emissions of carbon dioxide are increasing. The application of this mirror method could help convert carbon dioxide into useful fuels.
The study, titled ‘Optical cavity-mediated exciton dynamics in photosynthetic light harvesting 2 complexes,’ was published in Nature Communications.
Using advanced materials to reduce greenhouse gases
The team has made new progress when it comes to taking advantage of solar energy and light.
They used ultrafast laser spectroscopy, with the help of advanced materials, to show it would be possible to use solar energy to reduce the levels of greenhouse gases in the atmosphere in the long term.
“We have inserted so-called photosynthetic antenna complexes between two mirrors that are placed just a few hundred nanometres apart as an optical microcavity. You can say that we catch the light that is reflected back and forth between the mirrors in a kind of captivity,” said Tönu Pullerits, Professor of Chemical Physics at Lund University.
Making photosynthesis more efficient
The study shows that in this way, a strong interaction is achieved between the solar energy and the antenna complexes. This can create a ripple effect, that can speed up the energy transfer process.
In order for the photosynthetic light harvesting to function optimally, and to be used to, for example, produce fuel, all steps in the intricate process must be very efficient.
“If we can make the first steps of photosynthesis faster and more efficient, we can hopefully also make the light energy conversion of other systems more efficient,” explained Pullerits.
How can these results be useful? Pullerits hopes that the findings can be used in the future to develop larger units used on a global level, to utilise the energy of sunlight for absorbing carbon dioxide from the atmosphere and converting it into useful chemicals. It could be one of many solutions to overcome our current climate crisis.
“We have now taken a couple of initial steps on a long journey. You can say that we have set out a very promising direction,” Pullerits concluded.
