Researchers from ICFO and Yale have used graphene to efficiently detect mid-infrared light at room temperature and convert it into electricity. Detecting infrared light is of major importance for current applications in spectroscopy, materials processing, chemical, bio-molecular and environmental sensing, security and industry since the mid-infrared spectral region is the range where characteristic vibrational transitions and rotational excitations of many important molecules occur.
These vibrational and rotational excitations of many molecules, including hazardous and biological molecules, have frequencies that are found in the mid-infrared, which can be monitored by observing the absorption of light in this specific spectral range. However, currently available mid-infrared detectors are very inefficient, except those that can operate at cryogenic temperatures, because they incorporate superconducting elements. Thus, this low temperature limitation is a major drawback in having detectors integrated in devices for consumer products.