Band bending and quasi-2DEG in the metallized $\beta$-SiC(001) surface

TL;DR

This paper investigates how hydrogen adsorption induces metallization and forms a quasi-2D electron gas on the $eta$-SiC(001) surface, combining first-principles calculations with a simplified physical model.

Contribution

It introduces a simple model explaining the formation of a quasi-2D electron gas due to hydrogen adsorption on $eta$-SiC(001), supported by first-principles results.

Findings

Hydrogen adsorption causes band bending and surface metallization.

A quasi-2D electron gas is formed from donated electrons.

The simple model captures key features of the first-principles calculations.

Abstract

We study the mechanism leading to the metallization of the $\beta$-SiC(001) Si-rich surface induced by hydrogen adsorption. We analyze the effects of band bending and demonstrate the existence of a quasi-2D electron gas, which originates from the donation of electrons from adsorbed hydrogen to bulk conduction states. We also provide a simple model that captures the main features of the results of first-principles calculations, and uncovers the basic physics of the process.