Ultra-thin, flexible solar cells could soon cover and power your devices

Imagine solar panels so thin and flexible that you could power all your devices by sticking them on your home, car, smartphone and backpack. The technology could be here soon, thanks to the University of Oxford’s physics department, which may have made a breakthrough that could be ready for consumer use in the near future.

The technology is based on a technique that allows multiple layers of light-absorbing material to be placed inside a single, ultra-thin solar cell just one micron thick. For comparison, that’s just 0.00003937 inches, or 0.001 millimeters, thinner than some bacteria. Conventional photovoltaic cells are about 150 times thicker. In a statement, the researchers said the ultra-thin design allows the cells to be used as a coating, providing greater flexibility without sacrificing performance.

Scientists will formally reveal their methods for creating the cells, which are made from the mineral perovskite, in a paper to be published in a scientific journal later this year. The technology has already been certified by Japan’s National Institute of Advanced Industrial Science and Technology to convert 27% of sunlight that hits it into electricity. That’s a key figure because it matches — or even exceeds — the average efficiency of traditional solar panel materials.

“In just five years of experimenting with our stacked or multi-junction approach, we increased power conversion efficiency from about 6% to more than 27%, close to the limits of what single-layer photovoltaic cells can achieve today,” said Shuaifeng Hu, a researcher at the University of Oxford who worked on the project. “We believe that over time, this approach could enable photovoltaic devices to achieve much higher efficiencies, exceeding 45%.”

Some of the researchers behind the new technology have already begun trying to break into the market with perovskite solar cells. Oxford PV was founded by Henry Snaith, the Oxford professor who led the university’s work in photovoltaics and began large-scale production.

While most people imagine vast farms of shiny panels when they think of solar power, the hope is that perovskite cells could deliver renewable energy directly to homes, vehicles, and even clothes. Scientists have been working hard in recent years to make solar power a more feasible option, even going so far as to develop cells that can generate electricity from water as well as light. They’ve been largely successful: the cost of solar power has fallen by more than 80% since 2010.

“We can imagine perovskite coatings being applied to wider types of surfaces to generate cheap solar power, such as the roofs of cars and buildings, or even the backs of mobile phones,” says Junke Wang, an assistant professor at Oxford. “If more solar power can be generated in this way, we can foresee that in the long term there will be less need for silicon panels or for more and more solar farms.”

Given that CO2 emissions need to be drastically reduced, and quickly, to avert climate catastrophe, the future of shiny, energy-generating backpacks can’t come soon enough.