Local Electric In-Plane Potential Fluctuations in the CdTe/CdMgTe Based Multiple Quantum Wells
K. Nogajewski a, K. Karpierz a, J. Łusakowski a, M. Grynberg a and J. Kossut b
a Institute of Experimental Physics, University of Warsaw, Hoża 69, 00-681 Warsaw, Poland
b Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
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Received: 7 06 2008;
Unusual features in the magnetophotoconductivity spectra registered under far infrared illumination of the CdTe/CdMgTe based multiple quantum wells, uniformly n-doped are presented. It is shown that each spectrum exhibits one or two peaks of non-symmetrical shape, with position of their maxima dependent on the voltage applied to the sample. The peaks, observed in the configuration of the crossed electric and magnetic fields, are strongly shifted by a relatively weak in-plane electric field - of the order of 10-50 V/cm. Two different approaches to explain the observed influence are presented. Both are based on a two-step process leading to the photoconductivity signal. The first approach assumes that only the process of photon absorption is influenced by the external fields, the second one assumes that only the process of phonon assisted electron transfer from the excited donor state into the conduction band is influenced by the external fields.
DOI: 10.12693/APhysPolA.114.1259
PACS numbers: 71.55.Gs, 72.15.Rn, 72.80.Ey, 73.21.Fg