Far infrared selective absorption in uniformly iodine doped MBE CdTe/CdMgTe quantum wells - with no energetic scaling

Magnetophotoconductivity spectra of uniformly doped CdTe/Cd0.8Mg0.2Te quantum wells are presented. They were taken for fixed photon energy causing the transitions between the shallow donor levels splitted by an external magnetic field. They exhibit a surprising lack of sensitivity on the photon energy - for the energy range 2.2-13 meV the peaks in the spectra are recorded at the same magnetic field. The results are understood by taking into account the existence of local potential fluctuations in the structure which do cause localization of conducting electrons. The absorption can always occur on donors located in different regions and it leads to the mentioned lack of energetic scaling. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)