For as vital as photosynthesis is to the survival of literally everything on Earth, scientists still don’t know all that much about it or how it works. Now, however, researchers from the University of Michigan know one thing – the rate of molecular vibration plays a big role in how efficient the process of photosynthesis can be.

“Both biological and artificial photosynthetic systems take absorbed light and convert it to charge separation. In the case of natural photosynthesis, that charge separation leads to biochemical energy. In artificial systems, we want to take that charge separation and use it to generate electricity or some other useable energy source such as biofuels,” said Jennifer Ogilvie, an associate professor of physics and biophysics at the University of Michigan.

Her mention of electricity and biofuels isn’t misplaced – the research could one day lead to more efficient solar cells and energy storage systems. Before that happens, science needs to figure out how the most efficient solar cells of all – plant leaves – manage to be so efficient.

Ogilvie and her team used an ultra-fast spectroscopic laser system to fire light pulses at the photosystem II reaction centers (the part of a plant responsible for separating water into hydrogen and oxygen) of spinach leaves in order to incite photosynthesis. They’re looking for charge separation – the process of kicking electrons free from atoms in the initial steps of photosynthesis that ultimately converts solar energy into chemical energy for plants to grow and thrive.

The spectroscopic signals they recorded contained long-lasting echoes, of sorts, that revealed specific vibrational motions that occurred during charge separation.

“What we’ve found is that when the gaps in energy level are close to vibrational frequencies, you can have enhanced charge separation,” Ogilvie said. “It’s a bit like a bucket-brigade: how much water you transport down the line of people depends on each person getting the right timing and the right motion to maximize the throughput. Our experiments have told us about the important timing and motions that are used to separate charge in the photosystem II reaction center.”

Perhaps one day, the process can be reverse-engineered.