Magnetotransport measurements on modulation Si δ-doped pseudomorphic In0.2Ga0.8As/GaAs quantum wells

Abstract

The effect of doping concentration on electrical properties of Si δ-doped pseudomorphic In0.2Ga0.8As/GaAs quantum wells (QWs) was examined in this work. Magnetotransport measurements were carried out in the magnetic fields up to 12 T in the dark at the temperature of T = 1.7 K. The results were analysed using the fast Fourier transform (FFT). It was found that one electron subband was occupied in the QW with the doping concentrations of 2.3 × 1012 or 6.0 × 1012 cm-2. The parallel conduction was present in both samples, which increased with an increase of Si δ-doping concentration. The well-developed plateaus arising from the quantised Hall effect were observed in the Si δ-doped In0.2Ga0.8AsTGaAs QW with reduced parallel conduction. The two subbands remain occupied within the V-shaped potential well formed at the Si doping plane when the Si δ-doping concentration was high. The results of measurements in tilted magnetic fields, confirming the attribution of FFT peaks to the particular 2DEG systems, are also presented. Show more