Thread: Quantum Dots.
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May16-11, 12:18 AM
P: 107
Quote Quote by MATLABdude View Post
Quantum dots (and quantum wells) fluoresce--you apply energy to them, and they emit the energy as light. Light with a very narrow spread of frequencies, and converted from the applied energy (broad spectrum light, voltage, etc.) with very high efficiency.

That's very simplified, but a very brief Reader's Digest description of it.

EDIT: There's a nice picture on this site (first one down) that shows quantum dots being illuminated using a UV light source:
Thank you for the link although I am still a bit confused.

There are a few things which confuse me.

1. I can accept that electrons can be confined into a cage ( a small crystal in this case) but I get confused at the idea that the absence of electrons can also be confined. I think the concept of exciton has me a bit stumped. Escpecially where you seperate an exciton from atoms altogether. Is there anyway that in relation to Quantum Dots this process is explained in detail? How this is all formed?

2. Also what is stopping the electrons from leaving the trap or tunneling out?

3. Are Quantum dots permanent objects or do they decay very quickly?

4. How are these used to form qubits?

5. Or an accumulator to store data?

6. I've read about them called "artificial atoms" like an atom without a nucleus but still having electrons that form valence all of which is trapped. In that case the size of the "trap" is considerably larger than an atom since it is a molecule right? So wouldn't that artificial valence be huge because there is so much more space? I'm just trying to get an image of what this all looks like as clear as possible.

7. Why aren't Fullerenes used to create quantum dots?

8. Is an artificial ring of electrons that form a sort fo valence without a nucleus.. isnt that a monopole?