Quantum Dots to Stop Global Warming

OK, OK…it won’t stop global warming, but this is pretty cool and it has promise in being one key way to significantly reduce global energy consumption.

This previous post about LED lighting made this one point: LED’s are more efficient (they burn cooler and at a higher Kelvin temperature so they’re brighter per watt of energy) and that — if incandescent bulbs were replaced throughout America — we could reduce energy consumption. 10% here…10% there…pretty soon we’re talking about real savings and a reduction in dependence upon foreign oil.

Imagine me then stumbling across this article today about a Vanderbilt University student who accidentally came across a new way to “coat” LED lights with quantum dots to produce a bright, white light. The article in Science Daily recaps it nicely *and* discusses the Dept of Energy forecast that the energy savings could approach 29% by 2025:

The resulting hybrid LED gives off a warm white light with a slightly yellow cast, similar to that of the incandescent lamp.

Until now quantum dots have been known primarily for their ability to produce a dozen different distinct colors of light simply by varying the size of the individual nanocrystals: a capability particularly suited to fluorescent labeling in biomedical applications. But chemists at Vanderbilt University discovered a way to make quantum dots spontaneously produce broad-spectrum white light. The report of their discovery, which happened by accident, appears in the communication “White-light Emission from Magic-Sized Cadmium Selenide Nanocrystals published online October 18 by the Journal of the American Chemical Society.

In the last few years, LEDs (short for light emitting diodes) have begun replacing incandescent and fluorescent lights in a number of niche applications. Although these solid-state lights have been used for decades in consumer electronics, recent technological advances have allowed them to spread into areas like architectural lighting, traffic lights, flashlights and reading lights. Although they are considerably more expensive than ordinary lights, they are capable of producing about twice as much light per watt as incandescent bulbs; they last up to 50,000 hours or 50 times as long as a 60-watt bulb; and, they are very tough and hard to break. Because they are made in a fashion similar to computer chips, the cost of LEDs has been dropping steadily.

The Department of Energy has estimated that LED lighting could reduce U.S. energy consumption for lighting by 29 percent by 2025, saving the nation’s households about $125 million in the process.

Quantum dots, like white LEDs, have the advantage of not giving off large amounts of invisible infrared radiation unlike the light bulb. This invisible radiation produces large amounts of heat and largely accounts for the light bulb’s low energy efficiency.

Cool, heh? Read the original Vanderbilt University press release here, or any of these articles that cover this discovery as well as many others that will give you access to more info around quantum dots.