New Advancement Could Make Solar Panels 2 to 4 Times Cheaper. The findings may enable engineers to systematically identify the most effective molecules for extending the lifespan of perovskite solar cells, moving away from a reliance on time-consuming trial-and-error methods. A discovery at the University of Michigan provides key insights into preventing rapid degradation of perovskite semiconductors. This advancement has the potential to lead to solar cells that are two to four times less expensive than current thin-film solar panels. Perovskites may also be combined with the silicon-based semiconductors that are prevalent in today’s solar panels to create “tandem” solar cells that could surpass the maximum theoretical efficiency of silicon solar cells. "Silicon solar cells are great because they are very efficient and can last for a very long time, but the high efficiency comes with a high cost,” said Xiwen Gong, U-M assistant professor of chemical engineering. “To make high-purity silicon, temperatures over 1,000 degrees Celsius are needed. Otherwise, the efficiency won’t be as good.” Challenges with Perovskite Solar Cells.......The high temperature comes with higher economic and environmental costs. But while perovskites can be produced at lower temperatures, they degrade when exposed to heat, moisture and air. As a result, the lifespan of perovskite today is too short to be commercially competitive in solar panels. Gong’s research aims to make hardier perovskite solar cells, and her latest study published in the journal Matter suggests that bulky “defect pacifying” molecules are best at increasing the perovskites’ stability and overall lifespan. Understanding Perovskite Defects........Perovskite crystals contain lead atoms that aren’t fully bound to the other components within the perovskite. Such “undercoordinated sites” are defects often found on the crystal surfaces and at grain boundaries where there’s a break in the crystal lattice. These defects hinder the movement of electrons and speed up the decay of the perovskite material. We wanted to figure out what features on the molecules specifically improve the perovskite’s stability,” said Hongki Kim, a former postdoctoral researcher in chemical engineering and one of the study’s first authors. Research on Perovskite Additives.....read on https://scitechdaily.com/new-