Surprising discovery could boost performance of next-generation solar cells

Researchers at the University of Saskatchewan have cracked another problem plaguing next-generation solar panels. Using an X-ray experiment, they were able to determine why the efficiency of perovskite solar cells increases as humidity decreases. According to lead researcher Tim Kelly, the discovery came about by chance. His original research was to find out why a certain type of perovskite cell failed. He initially thought it had to do with the elements used in the material, but it turned out that humidity causes some atoms to be more mobile than they should be, leading to corrosion. The research paper reports the performance of the perovskite cell at 0%, 40% and 80% relative humidity. Kelly’s research has also identified potential solutions to the problem of premature cell failure, including using corrosion-resistant materials for the electrodes, buffer layers to prevent mobile ions from reaching the electrodes, or completely encapsulating the cell to keep out moisture. Perovskite has been a promising technology for years, but several hurdles have prevented its mass production. In particular, the atomic structure is prone to breakdown over time. But small improvements are occasionally made that bring us closer to these next-generation solar cells. For example, a new additive has been shown to improve stability at high temperatures. Other research has found superior coating layers that can help protect against moisture, which we see is crucial for performance. Perovskite solar panels require less energy to produce than traditional silicon, which translates into a big cost reduction. Perovskite is also able to absorb short-wavelength light more efficiently than silicon cells. However, it will take several years for these results to translate from laboratory experiments into finished products.