Researcher Esma Ugur displaying the perovskite/silicon tandem solar cell that broke the efficiency record in April 2023. Credit: KAUST Researchers in Saudi Arabia have just broken a record they themselves set just two months ago: a tandem solar cell with an unprecedented 33.7% efficiency. The challenge: Photovoltaic solar cells absorb light and convert it into electricity. You’ll find dozens of them in the average solar panel, and chances are they’ll be made from silicon, because it lasts a long time and is relatively cheap. Silicon solar cells aren’t terribly efficient, though — most commercial silicon cells convert just 18-22% of...