Temperature dependent anisotropic charge carrier mobility limited by ionized impurity scattering in thin-layer black phosphorus

TL;DR

This paper theoretically investigates how ionized impurity scattering affects the temperature-dependent anisotropic charge carrier mobility in thin-layer black phosphorus, revealing a weak temperature dependence consistent with experiments.

Contribution

It introduces a detailed theoretical model accounting for anisotropic electronic structure and temperature-dependent screening effects on mobility in black phosphorus.

Findings

Mobility decreases slowly with temperature below 100K.

Anisotropy ratio of mobility ranges from 1.9 to 3.2.

Results agree with experimental observations.

Abstract

Anisotropic charge carrier transport in black phosphorus limited by ionized impurity scattering at finite temperature is explored theoretically. The anisotropic electronic structure enters the calculation for the polarizability (screening), the momentum relaxation time, and the mobility. For finite temperature, scattering is not limited to the Fermi surface and the polarizability is temperature dependent. The impact of screening is investigated in detail with its dependence on carrier density and temperature. Competing with the thermal excitation effects, the temperature dependence of the polarizability is found to dominate for T<100K. As a result, the charge carrier mobility slowly decreases with increasing temperature. The weak temperature dependence of the mobility and its anisotropy ratio of 1.9-3.2 agree with published experimental data.