Atomic Movies May Help Explain Why Perovskite Solar Cells Are More Efficient

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In recent years, perovskites have taken the solar cell industry by storm. They are cheap, easy to produce and very flexible in their applications. Their efficiency at converting light into electricity has grown faster than that of any other material – from under four percent in 2009 to over 20 percent in 2017 – and some experts believe that perovskites could eventually outperform the most common solar cell material, silicon. But despite their popularity, researchers don’t know why perovskites are so efficient.

Now experiments with a powerful “electron camera” at the Department of Energy’s SLAC National Accelerator Laboratory have discovered that light whirls atoms around in perovskites, potentially explaining the high efficiency of these next-generation solar cell materials and providing clues for making better ones.

In recent years, perovskites have taken the solar cell industry by storm. They are cheap, easy to produce and very flexible in their applications. Their efficiency at converting light into electricity has grown faster than that of any other material – from under four percent in 2009 to over 20 percent in 2017 – and some experts believe that perovskites could eventually outperform the most common solar cell material, silicon. But despite their popularity, researchers don’t know why perovskites are so efficient.

Now experiments with a powerful “electron camera” at the Department of Energy’s SLAC National Accelerator Laboratory have discovered that light whirls atoms around in perovskites, potentially explaining the high efficiency of these next-generation solar cell materials and providing clues for making better ones.

“We’ve taken a step toward solving the mystery,” said Aaron Lindenberg from the Stanford Institute for Materials and Energy Sciences (SIMES) and the Stanford PULSE Institute for ultrafast science, which are jointly operated by Stanford University and SLAC. “We recorded movies that show that certain atoms in a perovskite respond to light within trillionths of a second in a very unusual manner. This may facilitate the transport of electric charges through the material and boost its efficiency.”

Continue reading at DOE / SLAC National Accelerator Laboratory

Image: From left: SLAC researchers Xijie Wang, Aaron Lindenberg and Xiaoxi Wu at the lab’s experimental station for ultrafast electron diffraction (UED).

Credits: Dawn Harmer / SLAC National Accelerator Laboratory