Bacterial processes in the depths of oceans could help to develop efficient solar cells

Deep sea

Nature is always a good source of inspiration for not only artists but also for scientists. It helped a lot in getting the best results. Now the researchers from University of Cambridge have used another natural phenomenon to make advancements in the field of solar energy utilization.

Researchers have studied the light capturing properties of the proteins of the Green Sulfur Bacteria, which are usually found in depths, sometimes below 2 kilometers, in oceans where light reaches in minute amounts. In some cases, these bacteria have the ability to utilize the 100% of the tiny amount of light by photosynthesis to produce electricity.

This field of research falls under the subject of “quantum biology” i.e. outside of classical physics.

Structure of protein complex in Green Sulphur bacteria (Credit: University of Cambridge)

There is a network of pigments held by protein complexes in the organisms that do photosynthesis. This is known as pigment-protein complexes (PPCs), where electrons are harvested. Usually in the organisms, the movement of the electrons through these systems causes the loss of energy but in the Green Sulfur Bacteria electrons move through the photosynthetic system without the loss of energy that is crucial for the organisms’ survival in one of the most inhospitable environments.

“Our research suggests that these natural PPCs can achieve ‘hot and fast’ energy transfer – energy flows that prevent complete cooling to the temperature of their surroundings – which has been proposed as a way of improving solar cell efficiency beyond limits currently imposed by thermodynamics.” Dr Alex Chin, from Cambridge’s Winton Programme for the Physics of Sustainability, said in a statement.

“Some of the key issues in current solar cell technologies appear to have been elegantly and rigorously solved by the molecular architecture of these PPCs – namely the rapid, lossless transfer of excitons (a mobile neutral combination of an electron and a hole) to reaction centres.”

Improving the efficiency of solar cells while reducing the cost of the panels and cells is one of the most important goals of the solar companies and this research could help to achieve these goals.