What They Say
Researchers at MIT’s Research Laboratory of Electronics (RLE) have developed a silicon chip with fully integrated LEDs that are said to be bright enough to enable state-of-the-art sensor and communication technologies. Working with GlobalFoundries, a group has developed a silicon LED (rather than a typical III-V material mix) that can produce enough light to transmit a signal 5 metres. It is still less bright than regular LEDs, but better than other silicon-based devices.
The team used the LED to send signals at frequencies up to 250 megahertz, indicating that the technology could potentially be used not only for sensing applications, but also for efficient data transmission. The team plans to continue developing the technology, but is already happy with progress.
In addition to cheaper manufacturing, the advance could improve LED performance and efficiency as electronics shrink to ever smaller scales. That’s because, at a microscopic scale, III-V semiconductors have non-ideal surfaces, riddled with “dangling bonds” that allow energy to be lost as heat rather than as light, according to Ram. In contrast, silicon forms a cleaner crystal surface.
What We Think
At this stage, the concept doesn’t seem likely to be bright enough for display applications. However, such silicon LEDs seem bound to appear somewhere, sometime! (BR)
