Effect of atomic-scale defects and dopants on phosphorene electronic structure and quantum transport properties

TL;DR

This study uses first-principles calculations to analyze how atomic-scale defects and dopants affect the electronic structure and quantum transport in phosphorene, revealing their impact on charge mobility and conduction regimes.

Contribution

It provides a detailed hybridization model and quantum transport analysis of doped and defective phosphorene, highlighting the effects on electronic properties and charge mobility.

Findings

Dopants create quasi-bound states and polarization effects depending on valence electrons.

External species induce band distortions leading to backscattering and varied conduction regimes.

Interstitial defects produce consistent transport signatures across different dopants.

Abstract

By means of a multi-scale first-principles approach, a description of the local electronic structure of two-dimensional and narrow phosphorene sheets with various types of modifications is presented. First, a rational argument based on the geometry of the pristine and modified P network, and supported by the Wannier functions formalism is introduced to describe a hybridization model of the P atomic orbitals. {\it Ab initio} calculations show that non-isoelectronic foreign atoms form quasi-bound states at varying energy levels and create different polarization states depending on the number of valence electrons between P and the doping atom. The quantum transport properties of modified phosphorene ribbons are further described with great accuracy. The distortions on the electronic bands induced by the external species lead to strong backscattering effects on the propagating charge carriers. Depending on the energy of the charge-carrier and the type of doping, the conduction may range from the diffusive to the localized regime. Interstitial defects at vacant sites lead to homogeneous transport fingerprints across different types of doping atoms. We suggest that the relatively low values of charge mobility reported in experimental measurements may have their origin in the presence of defects.