Science & Technology
Researchers develop perovskite solar cells that generate power underwater
Scientists have engineered perovskites—an alternative to silicon solar cells—to harness light wavelengths that penetrate seawater, opening possibilities for deep-ocean power generation.
Ars Technica
A research team at Yunnan University, led by Simin Ma, has created a new generation of solar cells capable of harvesting energy beneath the waves—addressing a challenge that would have saved the cartoon superhero Birdman from recharging trouble in an undersea adventure.
Why perovskites for underwater use?#
Perovskite-based solar cells offer distinct advantages over conventional silicon panels. They're economical to manufacture, can be produced as transparent or flexible films, and boast higher energy conversion efficiency. However, they come with a significant drawback: they degrade relatively quickly, especially when exposed to moisture. This apparent incompatibility makes them seem like an unlikely candidate for underwater deployment.
Yet perovskites possess a crucial trait that changes this calculus: their light-absorption properties can be precisely engineered through chemical modification. Silicon solar panels cannot function effectively underwater because water absorbs the wavelengths they're designed to capture. A strategically tuned perovskite cell, by contrast, can absorb the blue wavelengths that penetrate seawater—making electricity generation possible even at depth.
Engineering durability in saltwater#
The team's primary challenge wasn't adjusting the material to work at depth, but rather ensuring it could withstand the hostile underwater environment long-term. They identified an additive—polyhexamethylene guanidine hydrochloride—that addresses degradation on multiple fronts.
The compound creates a hydrophobic barrier protecting the material's interior while also strengthening the crystal structure itself. By preventing unwanted ion migration within the lattice and promoting larger, more stable crystals, the additive counteracts the common failure modes perovskites experience. As a bonus, the lower light intensity and cooler temperatures found underwater may actually extend the cell's operational lifespan, compared to surface conditions.
