An LED that can be integrated directly into computer chips

One problem with LEDs: It’s tough to make them from silicon. That means LED sensors must be manufactured separately from their device’s silicon-based processing chip, often at a hefty price.

But that could one day change, thanks to new research from MIT’s Research Laboratory of Electronics (RLE).

Researchers have fabricated a silicon chip with fully integrated LEDs, bright enough to enable state-of-the-art sensor and communication technologies. The advance could lead to not only streamlined manufacturing, but also better performance for nanoscale electronics.

The team designed a silicon-based LED with specially engineered junctions — the contacts between different zones of the diode — to enhance brightness. This boosted efficiency: The LED operates at low voltage, but it still produces enough light to transmit a signal through 5 meters of fiber optic cable. Plus, GLOBALFOUNDRIES manufactured the LEDs right alongside other silicon microelectronic components, including transistors and photon detectors. While Xue’s LED didn’t quite outshine a traditional III-V semiconductor LED, it easily beat out prior attempts at silicon-based LEDs.