Electron excitation and velocity

zhanghe

which kind of velocity are you talking about, phase velocity (k) or group velocity (dE/hdk)? different velocity, different answer.

DrDu

Read his post #3 and guess the answer!

zhanghe

When electron is excited from valence band to conduction band, i do not think we should try to understand the mechanism using classical picture, though quasi classical mechanics is applied widely in semiconductor but only limited in same band, I think.
let us go to quantum physics, outside the atom, when one electron is excited from one level to a higher one by photon, of course the velocity is changed, could you explain it? same principle in transition from band to band.