Modern transistors, which function as a computer’s brain cells, are only a few atoms long. If they are packed too tightly, that can cause all sorts of problems: electron traffic jams, overheating, and strange quantum effects. One solution is to replace some electronic circuits with optical connections that use photons instead of electrons to carry data around a chip. There’s just one problem: Silicon, the main material in computer chips, is terrible at emitting light.
Now, a team of European researchers says they have finally overcome this hurdle. On Wednesday, a research team led by Erik Bakkers, a physicist at Eindhoven University of Technology in the Netherlands, published a paper in Nature that details how they grew silicon alloy nanowires that can emit light. It’s a problem that physicists have grappled with for decades, but Bakkers says his lab is already using the technique to develop a tiny silicon laser that can be built into computer chips. Integrating photonic circuits on conventional electronic chips would enable faster data transfer and lower energy consumption without raising the chip’s temperature, which could make it particularly useful for data-intensive applications like machine learning.
“It’s a big breakthrough that they were able to demonstrate light emission from nanowires made of a silicon mixture, because these materials are compatible with the fabrication processes used in the computer chip industry,” says Pascal Del’Haye, who leads the microphotonics group at the Max Planck Institute for the Science of Light and was not involved in the research. “In the future, this might enable the production of microchips that combine both optical and electronic circuits.”