Effects of electron-impurity scattering on density of states in silicene: impurity bands and band-gap narrowing

TL;DR

This paper investigates how electron-impurity scattering affects the density of states in silicene, revealing gap narrowing, impurity band transformation, and optical conductivity dependence on impurity levels.

Contribution

It introduces a generalized multiple-scattering Green's function approach considering interband correlation to analyze impurity effects in silicene.

Findings

Energy gaps reduce at high chemical potential.

Impurity bands transform into band tails at low chemical potential.

Optical conductivity depends on impurity concentration in the terahertz range.

Abstract

Considering the interband correlation, we present a generalized multiple-scattering approach of Green's function to investigate the effects of electron-impurity scattering on the density of states in silicene. The reduction of energy gaps in the case of relatively high chemical potential and the transformation of split-off impurity bands into band tails for low chemical potential are found. The dependency of optical conductivity on the impurity concentration is also discussed for frequency within the terahertz regime.