Transport properties of Hg_0.80Mg_0.20Te grown by molecular beam epitaxy

Variable magnetic-field Hall measurement has been used to investigate the transport properties in Hg_0.80Mg_0.20Te molecular beam epitaxy films in the temperature range from 1.5 to 250 K. The experimental data have been analyzed by using a hybrid approach consisting of the mobility spectrum (MS) technique followed by a multicarrier fitting (MCF) procedure. Both the Shubnikov-de Haas measurements and the hybrid MS+MCF approach show three- and two-dimensional electronic behaviors. The two-dimensional electrons, with mobility in the range of 1-3 × 10³ cm²/V s and a sheet density about 10¹² cm^-2, are found and come from an accumulation layer near the HgMgTe-CdTe interface or the HgMgTe-vacuum interface. The temperature-dependent evolution of the bulk electron mobility indicates that the scattering mechanism in HgMgTe is very similar to that in HgCdTe, that is, ionized impurity scattering dominates at low temperature while lattice scattering dominates above 100 K.