June 15, 2009

Light-emitting transistor sets record

U.S. scientists have constructed a light-emitting transistor that has set a record for a signal-processing modulation speed.

University of Illinois researchers said they achieved a speed of 4.3 gigahertz, breaking the previous record of 1.7 gigahertz held by a light-emitting diode.

Then by internally connecting the base and collector of a light-emitting transistor, they also created a new form of light-emitting diode, which modulates up to 7 gigahertz -- breaking the speed record once again.

The university and licensee Quantum Electro Opto Systems in Melaka, Malaysia, reported the fabrication and testing of the new high-speed light-emitting transistor and the new tilted-charge light-emitting diode.

Simple in design and construction, the tilted-charge light-emitting diode offers an attractive alternative for use in high-speed signal processing, optical communication systems and integrated optoelectronics, said Professor Nick Holonyak Jr., who invented the first practical visible light-emitting diode more than 40 years ago.

Quantum Electro Opto Systems is a company formed by Gabriel Walter, CEO of the company, Professor Milton Feng and Holonyak to commercialize the light-emitting transistor and tilted-charge light-emitting diode technology.

The research that included graduate students Chao-Hsin Wu and Han Wui Then appears in the journal Applied Physics Letters.