U.S. researchers say they have broken the record they previously set for the world's fastest transistor, a development that could lead to much faster computers and more secure wireless communications.

Scientists at the University of Illinois Urbana-Champaign said Tuesday they created a transistor with a frequency of 845 gigahertz, about 20 per cent faster than the 704 GHz speed record they set last year. A gigahertz is a measure of frequency equal to one billion cycles a second.

Transistors are small electronic semiconductor devices that can control voltage or current by using a much lower voltage or electrical current. They are used in a wide range of electronic circuits, including computers and cellular phones. Computer microchips use millions of them.

The components' construction "enhances the electron velocity, hence, reduces both current density and charging time," said Milton Feng, the Holonyak chair professor of electrical and computer engineering at Illinois.

The new transistor, made of iridium phosphide and iridium gallium arsenide, brings the goal of making a terahertz — or one trillion Hertz — transistor within reach, the scientists said.

At room temperature, or 25 C, the transistor operates at 765 GHz. The speed increases to 845 GHz when the transistor is chilled to –55 C.

Details of the research are to be presented at the International Electronics Device Meeting in San Francisco, which ends Wednesday.

The researchers also refined their engineering techniques, making it possible for them to make smaller parts to be used in the transistor. The base is about 12.5 nanometres wide. A nanometre is one billionth of a metre.

The U.S. Defense Advanced Research Projects Agency funded the research, which has applications to "more effective combat systems," according to a statement by the University of Illinois.