A little more than half of the sun’s energy that reaches Earth does so as infrared rays. The longer wavelength of infrared light makes it less energetic, which makes it hard to capture with existing solar cells.
Researchers have made semiconductor nanocrystals that can convert infrared light to higher-energy visible light with an efficiency of over 5 percent, much higher than methods reported so far. The team could use the converted light to drive a chemical reaction that produces hydrogen fuel from methanol.
