Friday, June 7, 2013

An Itsy-Bitsy, Teeny-Weenie Quantum Dot

Dr. Marcus Jones is an assistant professor of Chemistry at the University of North Carolina at Charlotte. He has been researching, in conjunction with a team of collaborators, on what are called quantum dots.

Quantum dots are essentially nano-particles that take in energy from photons or electrons and then re-emit that energy as a specific frequency photon.

I’m sure you’re wondering what in the world I just said. Let me explain.

Imagine the smallest particle you can think of. Now downsize that about a thousand times. And then a hundred more, for good measure. That will be our nano-particle. For the purposes of the explanation, pretend that your nano-particle is wearing a bathing suit. An itsy-bitsy, teenie-weenie, yellow, polka-dot bikini will do. (The first part because your nano-particle is small. The second part because who doesn’t love yellow polka dots?)

            Your nano-particle is just sitting there, lounging, taking energy from photons or electrons. In other words, your nano-particle is sunbathing. After your nano-particle soaks this energy up, it is re-emitted in a specific frequency. Your nano-particle has such a healthy glow.

            Dr. Jones has researched the potential of using certain particles to increase the amount of energy absorbed or emitted. Gold, in particular, is effective. In research with solar panels, by placing a particle of gold next to the already existing particles, Dr. Jones says, the panels have the potential to be much better than the average panel in use. Gold is not necessary; other materials can be used to achieve the same effect. It is simply the most effective thus far. You can see this effect in the image below. In a natural state, the quantum dot absorbs a certain amount of energy and subsequently releases a certain amount of energy. In the assisted state, when a particle (such as gold, seen below and discussed above) is placed near the quantum dot, the dot has the potential to emit a far greater amount of energy than in the natural state, a phenomenon known as multiple emission.

            An interesting point, Jones notes, is that this research can be used in many potential applications. As mentioned above, it can be used for emittance efficiency; for example, in solar panels. It can also be used for absorbance efficiency; for example, highly efficient LED screens. It interested me during the interview to see that one solves a problem; one exacerbates it. One is targeted toward an overarching global issue (the environment), and one targets an overarching global appetite (technology and consumerism).

It reminds me of the Robert Frost poem, Nothing Gold Can Stay. Through Dr. Marcus Jones’ research with quantum dots, it might be possible to see gold and green exist in a symbiotic relationship, a give and take, a means to an end, and an end to a means. It depends on the application of the research, once it can indeed be applied.

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