The electronic properties of 2-electron shallow impurities (D- centers) in multiple quantum-well structures were studied by means of infra-red magneto-spectroscopy. The electron occupation of the shallow donor states at low temperatures, the temperature dependence of the occupancy, many-electron effects and resonant polaron interactions were considered.

J.P.Cheng, W.J.Li, J.L.Wang, B.D.McCombe, S.Holmes, W.Schaff: Solid State Communications, 1995, 93[5], 441-5