Growing HgTe/Cd0.735Hg0.265Te quantum wells by molecular beam epitaxy

HgTe/Cd0.735Hg0.265Te nanostructures with HgTe quantum wells 16.2 and 21.0 nm thick are grown without additional doping on (013)CdTe/ZnTe/GaAs substrates by the method of molecular beam epitaxy. The compositions and thicknesses of the wide-gap layer and quantum well in the course of growth are performed by means of ellipsometry. The accuracy is Δx ≅ ±0.002 mole fractions of cadmium telluride in determining the composition and Δd ≅ 0.5 nm in determining the thickness of the wide-gap layer and quantum well. The central fragments of the wide-gap layers ≈ 10 nm thick are additionally doped by indium for a ∼ 1015 cm−3 volume concentration of charge carriers to be reached. Galvanomagnetic research in a wide range of magnetic field intensities at liquid helium temperatures reveals dimensional quantization levels and the presence of a two-dimensional electron gas in grown nanostructures. High mobility of the two-dimensional electron gas μe is obtained: 2 · 105 and 5 · 105 cm2/V · s for electron densities Ns equal to 1.5 · 1011 and 3.5 · 1011 cm−2, respectively.