A new way to improve the efficiency of solar cells has emerged. They perform 5% better and scientists call this a huge improvement.

The development of new ultra-thin metal electrodes has allowed researchers to create translucent perovskite solar cells that are highly efficient and can be combined with traditional silicon cells to increase device performance. The research represents a step towards the creation of fully transparent solar cells.

“Transparent solar panels may someday take their place on the windows of homes and office buildings, generating electricity from sunlight that would otherwise be wasted,” said Kai Wang, assistant professor of materials science and engineering at the University of Pennsylvania and co-author of the study. “This is a big step – we have finally managed to create efficient translucent solar panels.”

Traditional solar cells are made from silicon, but scientists believe they are approaching the limits of this technology in an effort to create ever more efficient solar cells. Perovskite elements are a promising alternative, scientists said, and stacking them on top of traditional elements could create more efficient tandem devices.

“We have shown that we can create electrodes from a very thin layer of gold, almost a few atoms,” said Shashank Priya, assistant vice president for research and professor of materials science and engineering at Penn State. “The thin layer of gold has high electrical conductivity and at the same time does not interfere with the cell’s ability to absorb sunlight.”

The perovskite solar cell that the team developed achieved an efficiency of 19.8%, a record for a translucent battery. And when combined with a traditional silicon solar cell, the tandem device achieved an efficiency of 28.3%, compared to 23.3% for the silicon cell alone. Scientists reported their results in the journal Nano Energy.

“A 5% increase in efficiency is a tremendous result,” the researchers noted. “This means there is about 50 watts more sunlight for every square meter of solar cells.”