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ON THE MOVE  An exciton, illustrated here, transfers energy to an electron.

Stef Simmons, UCL Mathematical and Physical Sciences/Flickr (CC-BY 2.0)

Getting excited can kick a person’s energy to a higher level. At the nanoscale, strange almost-particles called excitons do the same trick.

In a crystal, thin film or even some liquids, an incoming particle of light can slam into an electron, bumping it to a higher energy level and leaving a hole at the energy level where the particle had been. The exciton is the excited electron paired with the resulting hole and can move energy in two ways: by physically hopping to a new molecule or transferring energy almost like an antenna transmitting a signal. Either way, the movement is quick, with the longest-lasting exciton existing for just a few milliseconds.

Even though excitons don’t last long, scientists were recently able to make images of how the quasiparticles moved (SN Online: 4/16/14). Investigating excitons’ ability to kick around nanoscale energy could improve scientists’ understanding of photosynthesis and lead to better solar cells, LEDs and semiconductor circuits.

photo of Ashley Yeager

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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