FAR-INFRARED MAGNETOOPTICAL STUDY OF HOLES AND ELECTRONS IN ZERO-BAND-GAP HGTE/CD0.85HG0.15TE SUPERLATTICES

Far-infrared (FIR) magnetotransmission and magnetotransport measurements have been performed on two HgTe/Hg0.15Cd0.85Te superlattices over a wide temperature region. Three of the six observed resonances are identified as cyclotron resonances of holes and electrons associated with the HH1 band, and of thermally excited electrons in the E1 band. Furthermore, the temperature dependence of the electron effective mass and its anisotropy is obtained from these experiments, and an attempt is made to correlate the observed mass behavior with the temperature-induced transition of the superlattices from the zero-band-gap to the open-band-gap regime. Finally, we briefly mention two further FIR resonances observed in the course of these experiments, which are identified as the 1s'2p+ transition and as cyclotron resonance of electrons occurring in the CdTe substrate of the superlattice. © 1990 The American Physical Society.