Silicon bulb aims to usurp LEDs

Group IV Semiconductor, based in Ottawa, aims to have prototype 40-watt silicon lights running in a pilot programme by the end of 2009, with a marketable bulb available by 2012.

A silicon bulb, which uses no toxic chemicals, has the potential to last for up to 10,000 hours and use 70% less electricity than a traditional incandescent bulb, according to Group IV.

Its British-born business development director Howard Tweddle says it has been researching the light-emitting characteristics of silicon since 2003.

Tweddle said a breakthrough came last year through a major investment deal that included Applied Materials, a manufacturer for the semiconductor, TFT and LCD display, glass and nano-technology sectors, based in America’s Silicon Valley.

“The agreement means our manufacturing design is being done in their world-class laboratories. We’re very excited about this,” said Tweddle.

“It has saved us millions in capital outlay for specialist equipment. In the next year we’ll be looking to partner with a firm who can manufacture to volume for the pilots.”

At the moment a light emitting diode bulb that gives off about 500 lumens will cost around £50. Tweddle believed the cost of Group IV’s silicon light bulb of 500 lumens would be equivalent to a compact fluorescent, about £2.50, but it would use less energy and emit less heat.

Group IV’s bulb is often called a “chip” because it is made of the same material as computer microchips and will be similar in size, around 1cm square and 1mm thick. In fact, it is two silicon wafers sandwiching a layer of nano-crystals of rare earth materials such as terbium.

The light emitting characteristics come from the fact that when a material is broken down into nano-size particles, they show different characteristics than when in a larger crystal state, explained Tweddle, a Cambridge engineering and electrical sciences graduate.