Carrier energy spectra and mobilities in semi-metallic HgTe quantum wells

In this work there is modeled electron mobility in the n-type Hg0.3Cd0.7Te / HgTe / Hg0.3Cd0.7Te quantum well (QW) being in semi-metallic state at T = 77 K. Calculations take into account longitudinal polar optical phonon (LPO) scattering, charged impurities scattering and electron-hole scattering. Boltzmann transport equation is solved directly to incorporate the inelasticity of LPO phonon scattering. Energy spectra and wave-functions are modeled using 8-band k-p-method which allows one to treat nonparabolicity of dispersion law and bands mixing properly. Modeling revealed that at liquid nitrogen temperature high mobility can be obtained for increased electron concentration in the well, which enhances 2DEG screening and decreases holes concentration. The growth of electron concentration in QW could be provided by delta-doping of barriers or by top-gate.