Making silicon devices responsive to infrared light
Researchers have tried a variety of methods to develop detectors that are responsive to a broad range of infrared light — which could form imaging arrays for security systems, or solar cells that harness a broader range of sunlight’s energy — but these methods have all faced limitations. Now, a new system developed by researchers at five institutions, including MIT, could eliminate many of those limitations.The new approach is described in a paper published in the journal Nature Communications by MIT graduate student Jonathan Mailoa, associate professor of mechanical engineering Tonio Buonassisi, and 11 others.Silicon, which forms the basis of most semiconductor and solar-cell technology, normally lets most infrared light pass right through. This is because the material’s bandgap — a fundamental electronic property — requires an energy level greater than that carried by photons of infrared light. “Silicon usually has very little interaction with infrared light,” Buonassisi says.Various treatments...