Schottky barrier formation and band bending revealed by first principles calculations

TL;DR

This study uses first principles calculations to analyze Schottky barrier formation and band bending at a metal/semiconductor interface, revealing dopant-dependent barrier heights and the role of dopant-induced dipoles.

Contribution

It provides atomic-scale insights into how dopants influence Schottky barrier height and band bending, enabling potential optimization of metal-semiconductor interfaces.

Findings

Schottky barrier height varies from 0 to 1.26 eV depending on dopant position.

Band bending is caused by dopant-induced dipole fields.

Pristine Au/TiO₂ interface shows no band bending.

Abstract

An atomistic insight into potential barrier formation and band bending at the interface between a metal and an n-type semiconductor is achieved by ab initio simulations and model analysis of a prototype Schottky diode, i.e., niobium doped rutile titania in contact with gold (Au/Nb:TiO$_2$). The local Schottky barrier height is found to vary between 0 and 1.26 eV depending on the position of the dopant. The band bending is caused by a dopant induced dipole field between the interface and the dopant site, whereas the pristine Au/TiO$_2$ interface does not show any band bending. These findings open the possibility for atomic scale optimization of the Schottky barrier and light harvesting in metal-semiconductor nanostructures.