Above: Image © Geoffrey.landis, Wikimedia Commons

If a recent investment by the Ontario provincial government is any indication, consumers could soon be moving towards a more efficient and environmentally-friendly way of lighting their homes. As part of the Innovation Demonstration Fund, the Ontario Ministry of Research and Innovation is investing $3.6 million in Ottawa-based Group IV Semiconductor Inc. (Group IV) to fund their development of low cost and energy-saving silicon-based solid-state light-bulbs.

Most people continue to light their homes with incandescent light bulbs. Although these bulbs are enjoyed for the soft, “ambient” type of light they provide and are relatively cheap to manufacture, they are also very inefficient. This is because the light is produced by super-heating a very thin metal filament until it glows. As a consequence, up to 95 per cent of the electricity, or energy, used to “light” the bulb is lost as heat and only five per cent ends up as light.

Did you know? About 15 per cent of the world’s energy consumption is for lighting, at a cost of $12 billion world-wide.

In recent years there has been a push towards fluorescent light bulbs, which are more efficient than an incandescent, but still lose about 75 per cent of energy to heat. Fluorescent bulbs produce light by passing electricity through mercury gas within the bulb, which excites the mercury atoms. When the mercury atoms return to their unexcited state, they release ultraviolet (invisible) light that activates the phosphor coating inside the bulb, causing it to give off visible light. Unfortunately, fluorescent light bulbs are quite expensive to make and disposal of bulbs containing toxic mercury is a problem.

Did you know? Replacing all the incandescent light bulbs in Canada with solid-state light bulbs would reduce greenhouse gases by 5 million tonnes a year — equal to taking 800,000 cars off the roads.

Enter solid-state lamps, the most common example of which is the LED (light-emitting diode). Semiconductor materials in solid-state lamps directly convert electricity into light without having to heat filaments or activate gas, making them highly efficient with little energy lost as heat. Unfortunately, most LEDs do not provide the same level of brightness as incandescent or fluorescent bulbs, and the compound semiconductor materials used to make them are very expensive. In response to these problems, Group IV has developed a solid-state lamp based on silicon, which is a cheaper semiconductor than those used in LEDs. This lamp promises to provide the energy efficiency of LEDs and other solid-state lamps, but with the brightness and low cost of more conventional bulbs. Ontario’s investment in Group IV will allow the company to begin testing the production of these silicon-based lamps on a larger scale.

Did you know? The compound semiconductor materials used to make LED lights are expensive, often requiring a combination of gallium indium nitride crystals and gallium nitride crystals.

Learn more!

CBC News - Technology and Science - 'Solid-state' light uses one-10th energy, maker says

Are Compact Fluorescent Lightbulbs Dangerous?: Scientific American

HowStuffWorks "Are fluorescen bulbs really more efficient than normal light bulbs?"

Group IV Semiconductor

What is Solid State Lighting?

Ontario Ministry of Research and Innovation

Article first published on March 10, 2010.

Photo Credit: Wikipedia commons

May Cheng

I am a PhD student in the Department of Cellular and Physiological Sciences at UBC, where I am investigating the electrical properties of cardiac potassium channels. When not in the lab, I'm probably cooking up a storm, immersed in a book, or catching a movie.

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