Ultrahigh Doping of Graphene Using Flame-Deposited MoO3

TL;DR

This paper presents a rapid flame synthesis method to achieve ultrahigh, stable p-type doping of graphene with MoO3, significantly improving doping levels and stability over previous techniques, and reducing contact resistance.

Contribution

The study introduces a flame synthesis technique for direct MoO3 growth on graphene, enabling ultrahigh, stable doping and lower contact resistance, surpassing existing deposition methods.

Findings

Achieved doping of ~7x10^13 1/cm^2 in graphene.

Flame-deposited MoO3 provides over 5x higher doping than electron-beam methods.

Reduced metal-graphene contact resistance to ~200 Ohm-um.

Abstract

The expected high performance of graphene-based electronics is often hindered by lack of adequate doping, which causes low carrier density and large sheet resistance. Many reported graphene doping schemes also suffer from instability or incompatibility with existing semiconductor processing. Here we report ultrahigh and stable p-type doping up to ~7x10^13 1/cm^2 (~2x10^21 1/cm^3}) of monolayer graphene grown by chemical vapor deposition. This is achieved by direct polycrystalline MoO3 growth on graphene using a rapid flame synthesis technique. With this approach, the metal-graphene contact resistance for holes is reduced to ~200 Ohm-um. We also demonstrate that flame-deposited MoO3 provides over 5x higher doping of graphene, as well as superior thermal and long-term stability, compared to electron-beam deposited MoO3.