Is there a definition of quantum dot that everybody agrees? I searched intensively both from google and from web of science, but I couldn't find a formal definition. e.g (wiki says) A quantum dot is a semiconductor whose excitons are confined in all three spatial dimensions. confined but how much confined? Is there a consensus on that, like; "when domain size is smaller than most probable de broglie wavelength, than it is quantum dot" or is it about excitations like "if there is no excitation, then it is quantum dot?" But this cannot be since we can make qdots with thousands of particles..