I'm having a hard time understanding how photon absorption and emission in metals (conductors) compares to semiconductors. Obviously, in SCs, absorbed photons lead to electron-hole pairs and emitted photons correspond to recombinations. I don't exactly understand how this process works in metals, since we don't even consider holes in the first place (and have essentially no band gap).
Do we just consider absorbed photons as promoting electrons to excited states, rather than pair generation?
Why exactly do metals emit absorbed light rapidly? I've read that light induces alternating currents on the metal surface and that ACs rapidly emit light, but I have no idea why. I'm not sure what alternating currents have to do with this (I'm sure there is an obvious explanation I should be familiar with).
I'm more familiar with band structure in SCs and therefore I'm having a hard time comparing radiative processes in metals to SCs.
Best Answer
Probably, it is useful to imaging absorption/emission in metals as an excitation or relaxation of the electron plasma. In the case of absorption, the energy of light is spent on oscillating of electron plasma supplemented by accelerating of electrons. For beginning, understanding of Drude theory of metals will be useful.