Impurity affected transport properties of quantum well heterostructures with electronic and high-κ dielectric quantum screening

Abstract

The effect of electronic and high-κ dielectric quantum screening (ES and DS) on the impurity-limited electron transport properties of quantum well/high-κ dielectric barrier type heterostructures with two-dimensional electron gas (2DEG) is studied theoretically. Characteristic of these heterosystems the 2D compound forms of screened impurity potential are employed for the first time. In the framework of 2D Debye-Hückel potential form an electron momentum relaxation time ($\tau$) expression depending on the impurity 2D screening radius is obtained analytically. A numerical analysis of $\tau$ is carried out for the realistic HfO/InSb/HfO₂ QW heterostructure taking account both the finite mismatch of the energy bands at the heterointerface and the energy band non-parabolicity of InSb. The contributions of screened potential compound 2D forms to $\tau$ are established depending on QW width. A significant suppression of the scattering rate ${\tau }^{-1}$ (by an order of magnitude) is received with accounting of ES + DS combined effect.