MIT Creates A Tiny LED That Can Be Integrated Directly Into Computer Chips

LEDs are used in all manner of projects and devices from living room lights to microelectronics. One example in a common device is the use of an LED proximity sensor in many smartphones. That sensor can tell if the device is next to your face and turn the screen off as a result. LEDs are also used for distance measurement in autofocus cameras and gesture recognition.

One challenge for LED production is that it's difficult to make them from silicon meaning the LED sensor has to be made separately from the device it's embedded in. That could be changing with a breakthrough from the MIT Research Laboratory of Electronics. In the lab, researchers were able to fabricate a silicon chip with fully integrated LEDs.

The LEDs are bright enough to enable state-of-the-art sensor and communication technologies. MIT's discovery could lead to streamlined manufacturing and improved performance for nanoscale electronics. Typically silicon makes for a poor light source. To get around that issue, electrical engineers usually make LEDs from other materials.

The silicon-based LED researchers developed features specially engineered junctions, which are contacts between different zones of the diode, to enhance brightness. The technique boosted the efficiency allowing the LED to operate at low voltage while producing enough light to transmit a signal through five meters of fiber-optic cable.

The best news is that the foundry can manufacture the LEDs alongside other silicon microelectronic components, such as transistors and photon detectors. The team was clear that the new LED doesn't outshine traditional III-V semiconductors used for LED manufacturing. It did easily beat prior attempts at silicon-based LEDs. Researchers see a day when LED technology is built right on the silicon processor with no separate factory needed.