An electron-hole pair consists of an excited Electron and the unoccupied valence state described as an electron hole. Promoting a valence Electron across a semiconductor band gap creates such a pair without changing the total electric charge. The carriers can separate under an electric field, or undergo electron-hole recombination. A bound electron-hole pair is an exciton; an arbitrary unbound pair need not be an exciton.
New to topics? Read the docs here!