Transport and Optical Properties of Single- and Bilayer Black Phosphorus with Defects

TL;DR

This study investigates how short- and long-range defects affect the electronic and optical properties of single- and bilayer black phosphorus, revealing defect-induced localization, reduced mobility, and suppressed anisotropy in optical excitations.

Contribution

It provides a detailed analysis of defect effects on black phosphorus's electronic, optical, and magneto-optical properties using the tight-binding propagation method.

Findings

Defects cause localization and reduce charge mobility.

Optical anisotropy is suppressed by defects.

Landau levels show sublinear dependence on magnetic field.

Abstract

We study the electronic and optical properties of single- and bilayer black phosphorus with shortand long-range defects by using the tight-binding propagation method. Both types of defect states are localized and induce a strong scattering of conduction states reducing significantly the charge carrier mobility. In contrast to properties of pristine samples, the anisotropy of defect-induced optical excitations is suppressed due to the isotropic nature of the defects. We also investigate the Landau level spectrum and magneto-optical conductivity, and find that the discrete Landau levels are sublinearly dependent on the magnetic field and energy level index, even at low defect concentrations.