Graphene-Semiconductor Contact

TL;DR

This paper provides a comprehensive analysis of graphene-semiconductor junctions, revealing their unique electronic properties, tunable barriers, and experimental methods to characterize these interfaces, positioning them as a new archetype of semimetal-semiconductor contacts.

Contribution

It introduces a systematic treatment of graphene-semiconductor contacts, deriving generalized interface equations and analyzing their unique electronic and capacitive properties.

Findings

Graphene-semiconductor junctions exhibit exotic electronic properties due to graphene's finite density of states.

The barrier height in these junctions is tunable and related to junction capacitance.

Experimental methods for characterizing junction parameters and observing inversion layers are discussed.

Abstract

A systematic treatment of graphene-semiconductor junction is presented. Finite density of states at the Fermi level of graphene leads to exotic electronic properties at graphene-semiconductor interface. Quite generally, the Schottky-Mott limit and the sum rule of barrier heights are violated due to the internal potential of graphene. By merging the principal characteristics of semiconductor-semiconductor and metal-semiconductor junctions, the graphene-semiconductor contact may be considered as an archetype of unprecedented \emph{semimetal-semiconductor junction}. Generalized interface equations disclose the coupling of junction characteristics with the density of charge carriers in graphene. It will be shown that the well-known effect of tunable barrier height is directly related to the junction capacitance. Furthermore, the relative impact of image-force effect in the presence of barrier tunability is investigated. Experimental methods to gain built-in potential, barrier height, and capacitance of the junction are discussed in detail. Also the development of strong inversion layer at the interface of graphene-silicon samples is uncovered by analyzing experimental data.