Next-generation solar materials are cheaper and more sustainable to produce than traditional silicon solar cells, but hurdles remain in making the devices durable enough to withstand real-world conditions. A new technique developed by a team of international scientists, including Penn State faculty Nelson Dzade, could simplify the development of efficient and more durable perovskite solar cells that still achieve a high efficiency of 21.59 percent conversion of sunlight to electricity.
Perovskite solar cells, named for their unique crystalline structure that excels at absorbing visible light, are more affordable and more sustainable to produce, according to Dzade. But the leading candidates used to make these devices, hybrid organic-inorganic metal halides, contain organic components that are susceptible to moisture, oxygen, and heat, can lead to rapid performance degradation, the scientists said.
To overcome issues in degradation due to changes in the crystalline structures, the scientists developed a dual deposition technique that combined two photoactive polymorphs of cesium lead iodide to form a phase-heterojunction. The combination suppresses the undesirable changes, the scientists said.
The researchers then fabricated a device that maintained more than 90 percent of the initial efficiency after 200 hours of storage under ambient conditions, Dzade said.
The researchers said the technique could pave the way for the development of additional solar cells based on all inorganic perovskites or other halide perovskite compositions.
“With this approach, we believe it should be possible in the near future to shoot the efficiency of this material past 25 percent,” Dzade said. “And once we do that, commercialization becomes very close.”