Nanoscale Light Sensor Sees Color

Researchers at the University of Pittsburgh have created a light sensor that is just four nanometers wide and can detect light on a nearly atomic scale. The average human hair is 80,000 nanometers wide. Pitt Physics Professor Jeremy Levy says they built upon previous University of Pittsburgh research that allows scientists to “draw” electronic paths separated by just a few atoms on the surface of a semiconductor. “If you want to detect light at the near-atomic scale this might be the best tool for doing that,” says Levy, “the actual sensitivity over the area that we are interested in is actually very large.”
Levy says the sensor could address a pair of problems scientists face when dealing with light sensitive materials. He says, ”It’s quite often difficult to integrate the optical and electronic components, but because we have this platform where we can create nano electronics it is very natural for us to incorporate the optical and electronic properties. So once we detect light it is very easy for us to read it out electronically.” The sensor also has the ability to see color in ways that most other sensors cannot. “What we found was that we could change the sensitivity to various colors of light simply by changing the electrical conditions,” says Levy. Most photo detectors measure that they have absorbed light but cannot tell the color the light. “In some sense, it’s a color sensor,” says Levy.