It was recalled that recent magneto-optical studies of selectively doped multiple quantum-well structures had included the study of negative-donor centers (D- centers) in quantum wells. It was emphasized that high magnetic fields were helpful in studying the formation mechanism of these centers, in elucidating their energy spectrum and in obtaining valuable information concerning the electron-phonon coupling for a 2-electron system in 2 dimensions.

S.Huant, A.Mandray, B.Etienne: Solid State Communications, 1995, 93[5], 435-9