Quantum physics and photosynthesis make solar cells brilliant

1 Dec 2016

Sunlight on a leaf. Image: Yvdalmia/Shutterstock

A team of researchers has melded the worlds of biology and quantum physics to develop a new model of solar cells, which could significantly increase their efficiency to unprecedented levels.

The latest development in solar cells technology is rapidly blurring the lines between artificially made panels of silicon, to ones that replicate the leaves of a plant more and more, using photosynthesis.

The latest research into the technology is taking it up another notch, by melding the seemingly different scientific fields of biology and quantum physics.

A research team from the University of California, Riverside, led by Prof Nathan Gabor, wanted to replicate a plant’s ability to absorb fluctuating amounts of energy from the sun.

While common in nature, current affordable solar cell technology is only 20pc efficient, and incapable of replicating this basic process, resulting in wasted energy harvesting.

To overcome this, the team developed a whole new type of quantum heat engine photocell, which helps to manipulate the flow of energy in solar cells.

In an unexpected turn of events, the researchers found that this new engine photocell was able to regulate these conversions as required, but could do it entirely of its own accord, like a natural leaf.

Answers questions on photosynthesis

Using conventional solar cells, any fluctuations in solar power must be suppressed by voltage converters and feedback controllers, dramatically reducing the overall efficiency.

Yet the breakthrough came following the team’s discovery that by simply incorporating two photon-absorbing channels, rather than just one, energy glow naturally regulates itself in a photocell.

The discovery also played a part in helping to answer why so many species of plants on Earth are green, as while the colour is the most radiant on the solar power spectrum, its regulatory benefits are minimal.

However, the natural regulation of energy found in the quantum heat engine photocell may play a critical role in the photosynthesis in plants, perhaps explaining this predominance of green plants.

The team’s research has been published in the journal Nano Letters.

Colm Gorey was a senior journalist with Silicon Republic