I LED – acronym for Light-Emitting Diode, light emission – components are widely used in the world of electronics and, especially in recent years, also in the lighting world. These components are not only used as “warning lights”, for example to signal a charging status or an active function of a device, but are also used in the field of sensors. Proximity sensors or face recognition systems are based, for example, on LEDs that emit light outside the visible spectrum .

Currently the integration of LEDs is burdened by a heavy limit: they are difficult to achieve using silicon , which implies a separate production process compared to that of silicon-based components and often more expensive. At MIT in Boston, however, research was carried out that showed the possibility of creating a silicon chip with integrated LEDs with sufficient brightness to be used in the field of sensors and communication.

Silicon LED: MIT takes important steps forward

Normal LEDs are made using III-V semiconductors , i.e. based on chemical elements present in the third and fifth columns of the periodic table and which have a higher optical efficiency than that of silicon (which is found in the fourth column). Silicon is therefore a poor light source. Jin Xue , a PhD student of Research Laboratory of Electronics of MIT , has managed to remedy this by designing junctions with specific characteristics and paying particular attention to the aspect of efficiency, so as to allow the operation of the LED low voltage but such as to be able to generate a light pulse capable of propagating along 5 meters of optical fiber .

Also participated in the MIT project GLOBALFOUNDRIES , which demonstrated the possibility of concretely producing these LEDs together with other silicon-based components, such as transistors and photon detectors . The new LED is not yet capable of exhibiting the same performance as a III-V semiconductor based LED, but it represented a significant step forward compared to previous attempts at Silicon-based LED .

What was developed by MIT could represent a breaking point from the production point of view, narrowing the possibility of making devices more easily and with better performance .