Epitaxial Growth of Uniform Single-Layer and Bilayer Graphene with Assistance of Nitrogen Plasma.

Shaoen Jin,Gan Liu,Xiaodong Qiu,Qichao Tian,Xiaoxiang Xi,Yi Zhang,Libo Gao,Hang Zheng,Can Wang,Wang Chen,Junyu Zong

doi:10.3390/nano11123217

Abstract

Graphene was reported as the first-discovered two-dimensional material, and the thermal decomposition of SiC is a feasible route to prepare graphene films. However, it is difficult to obtain a uniform single-layer graphene avoiding the coexistence of multilayer graphene islands or bare substrate holes, which give rise to the degradation of device performance and becomes an obstacle for the further applications. Here, with the assistance of nitrogen plasma, we successfully obtained high-quality single-layer and bilayer graphene with large-scale and uniform surface via annealing 4H-SiC(0001) wafers. The highly flat surface and ordered terraces of the samples were characterized using in situ scanning tunneling microscopy. The Dirac bands in single-layer and bilayer graphene were measured using angle-resolved photoemission spectroscopy. X-ray photoelectron spectroscopy combined with Raman spectroscopy were used to determine the composition of the samples and to ensure no intercalation or chemical reaction of nitrogen with graphene. Our work has provided an efficient way to obtain the uniform single-layer and bilayer graphene films grown on a semiconductive substrate, which would be an ideal platform for fabricating two-dimensional devices based on graphene.

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
Graphene can be used as an ideal substrate for the epitaxial growth of novel two-dimensional (2D) materials due to its native weak van der Waals interaction at the interface [4,5,6]
Combing the scanning tunneling microscopy (STM), reflection high-energy electron diffraction (RHEED), angle-resolved photoemission spectroscopy (ARPES), and X-ray photoemission spectroscopy (XPS), we studied the surface morphology, band structure, and chemical bonding formation of these samples

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. An atomically single layer of carbon sp bonded in a honeycomb lattice, has attracted enormous attentions of researchers due to its novel physics and broad application prospects [1,2,3]. Graphene can be used as an ideal substrate for the epitaxial growth of novel two-dimensional (2D) materials due to its native weak van der Waals interaction at the interface [4,5,6]. Graphene shows great application potential in advanced devices. The single-layer graphene (SLG) photodetectors have the broadest photo response with high photoconductive gain 8.61 AW−1 [7].

Methods

Results

Conclusion