Science Friday Fun
An accidental discovery announced this week has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The miniature breakthrough adds to a growing trend that is likely to eventually make Thomas Edison's bright invention obsolete.
Michael Bowers, a graduate student at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. That's less than 1/1000th the width of a human hair.
...When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened.
"I was surprised when a white glow covered the table," Bowers said. "The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow."
Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn't pretty, but it produced white light similar to a regular light bulb.
The new device gives off a warm, yellowish-white light that shines twice as bright and lasts 50 times longer than the standard 60 watt light bulb.
Not only is this happy accident tremendously useful--the Dept. of Energy says that such a switch could use 29% less energy than conventional bulbs--but this could be a beautiful, fun thing.
If the new process can be developed into commercial production, light won't come just from newfangled bulbs. Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white.
How cool is that? Why, it's almost as cool as solar panels no thicker than your average photo film.
Silicon-based solar panels remain rigid, bulky and expensive a half-century after their introduction. Alan Heeger, the 2000 Nobel Prize winner in chemistry, is working to change that.
...Heeger and his colleagues at Konarka, the Lowell, Mass.-based company he co-founded, can “print” strips of photovoltaic (PV) plastic as thin as photographic film. As with traditional PV panels, sunlight is converted into electrical energy. The advantage over traditional crystalline silicon on a glass substrate: Heeger’s power plastic is 100 times thinner, as well as more pliable, cheaper and easier to mass-produce. Imagine electricity-generating awnings, tents, roofs and even clothing. “Solar energy is going to happen,” says Heeger. “It will happen sooner and on a larger scale if we can provide a lower-cost technology.”
For some reason, all I can think of is that scene in "The Graduate" - "I've got one word for you: plastics."
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