Design and modelling of PbTe wide quantum wells based on the n–i–p–i concept

Abstract

Wide quantum wells (WQW) are of special interest because of their intermediate regime between 2D and 3D behaviour. According to the n–i–p–i concept, the design is based on a p–n–p structure with non-depleted n- and p-layers which form a wide quantum well (channel width 100–1000 nm). We present self-consistent model calculations for wide and multiple PbTe quantum wells in a perpendicular magnetic field. The calculations take into account the feedback of the carrier redistribution between the subband–Landau levels on the confining potential with some unusual consequences. Instead of an oscillating Fermi energy the width of the n-channel varies as a function of the magnetic field. A WQW does not allow the occurrence of integer filling factor one at high magnetic fields. In a non-periodic multiple quantum well the different potential minima are forced to match one another.