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Quantum dots

Hi! Why are the absorption and emission of quantum dots enhanced compared to other conventional bulk materials? This is kind of a guess but is it due the the Beer-Lambert law? Since the depth is so small. Are there any more reasons they are enhanced?
Thanks!
Original post by Yscchem
Hi! Why are the absorption and emission of quantum dots enhanced compared to other conventional bulk materials? This is kind of a guess but is it due the the Beer-Lambert law? Since the depth is so small. Are there any more reasons they are enhanced?
Thanks!


In an extended material the electrons can often just "slosh about" as they like doing lots of random things. However, when you confine a quantum system in a small enough region of space (typically of order the wavelength of light or smaller), you start to change the energy levels it is allowed to occupy. In that way you can “tune” it to have a resonance at a particular wavelength of light or equivalently, a particular energy. If a system is resonant at a given frequency / energy / wavelength, it interacts much more strongly there, some pretty pictures of this and a bit more technical detail at the link below.

https://www.sigmaaldrich.com/technical-documents/articles/materials-science/nanomaterials/quantum-dots.html

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