Spatial distribution of local density of states in vicinity of impurity on semiconductor surface

TL;DR

This paper provides a theoretical analysis of how local electronic surface states are affected by impurities on a semiconductor surface, revealing voltage-dependent features and anisotropic spatial behavior.

Contribution

It introduces a detailed theoretical model accounting for changes in the density of states near impurities, highlighting voltage-induced phenomena and directional differences in surface state distribution.

Findings

Formation of a downfall at specific bias voltages near impurities

Series of downfalls depending on distance from impurity

Anisotropic behavior of local density of states with distance

Abstract

We present the results of detailed theoretical investigations of changes in local density of total electronic surface states in 2D anisotropic atomic semiconductor lattice in vicinity of impurity atom for a wide range of applied bias voltage. We have found that taking into account changes in density of continuous spectrum states leads to the formation of a downfall at the particular value of applied voltage when we are interested in the density of states above the impurity atom or even to a series of downfalls for the fixed value of the distance from the impurity. The behaviour of local density of states with increasing of the distance from impurity along the chain differs from behaviour in the direction perpendicular to the chain.