Light detectors that distinguish between different colors
The new detector, described in a paper in Nature Nanotechnology on May 22, operates about 10 to 100 times faster than current comparable thermoelectric devices and is capable of detecting light across a wider range of the electromagnetic spectrum than traditional light detectors. In traditional light detectors, incoming photons of light are absorbed in a semiconductor and excite electrons that are captured by the detector. The movement of these light-excited electrons produces an electric current—a signal—that can be measured and quantified. While effective, this type of system makes it difficult to "see" infrared light, which is made up of lower-energy photons than those in visible light.
Because the new detectors are potentially capable of capturing infrared wavelengths of sunlight and heat that cannot be collected efficiently by conventional solar materials, the technology could lead to better solar cells and imaging devices.
"In nanophotonics, we study the way light interacts with structures that are much smaller than the optical wavelength itself, which results in extreme confinement of light. In this work, we have combined this attribute with the power conversion characteristics of thermoelectrics to enable a new type of optoelectronic device," says Harry Atwater,
Read more at: https://phys.org/news/2017-06-nanostructures-rainbow.html#jCp
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