Glowing nanowires could speed up computer processors and telecommunications networks
SOURCE: “Electrically Excited Infrared Emission from InN Nanowire Transistors”
Jia Chen et al.
Nano Letters 7: 2276-2280
RESULTS: IBM researchers have demonstrated a new technique for converting electricity into infrared light in indium nitride nanowires. Previously, getting a nanowire to emit light required injecting it with both electrons and “holes”–a physicist’s shorthand for the absence of an electron. (An electron that leaps to fill a hole may leave another hole behind it; in this sense, the hole can be seen as moving.) Since the new technique requires only the injection of electrons, it is simpler and potentially more efficient.
WHY IT MATTERS: Light-emitting nanowires could be integrated into the microchips used in telecommunications. They could also be used for optical communication between devices on computer chips, which could significantly improve processing speed. Infrared light, which has previously been difficult to produce in nanowires, is ideal for use in silicon-based chips, the industry standard. What’s more, the electron-only injection method yields light emitters that are brighter and more efficient than other nanowire devices.
METHODS: The researchers grew indium nitride nanowires by combining indium and indium oxide with ammonia at 700 ºC. The nanowires, which were suspended in rubbing alcohol, were then dispersed over a silicon wafer patterned with electrodes. The wires bridged the electrodes, forming transistorlike devices. A current delivered by the electrodes caused the nanowires to emit light.
NEXT STEPS: Using these light-emitting nanowires in microchips will require methods for arranging nanowires into complex circuits at high speeds.