Synthesis of graphene on dielectric substrates

Abstract

Graphene has caught wide attention due to its unique and excellent properties since its first isolation in 2004. Controllable synthesis of graphene with large-area and high-quality is critical for the realization of various graphene based applications. Although scalable graphene could be grown on metal substrates by chemical vapor deposition (CVD) method, as-grown graphene needs to be transferred onto a dielectric layer for further devices construction. The direct synthesis of graphene on dielectric substrates could avoid the damages and contaminations caused by the transfer process. In this review, we provide a comprehensive progress regarding the synthesis of graphene on dielectric substrates including traditional ones (i.e., glass, quartz, amorphous SiO2, Si3N4 and Al2O3) and two dimensional hexagonal boron nitride films. The growth techniques based on CVD approach are classified into metal-catalyzed, metal-free and plasma-enhanced CVD. The growth procedures for each technique are first described, and the main results in terms of as-grown graphene sample's properties such as its electron transport, layer number, crystallinity and quality are then discussed. These studies point to the important role of techniques and experimental conditions in tuning various properties of graphene product. With this idea in mind, we summarize the information of growth conditions and graphene-related properties in different cases, which provides a useful reference for comparing and evaluating the advantages and disadvantages of various techniques. Moreover, we discuss the major challenges in this growing field. Although metal catalyzed CVD could achieve the grown graphene placed on the underlying dielectric substrates by the post removal of metal, it still cannot avoid the metal contaminations or damage of graphene. The main limitation for graphene metal-free synthesis on dielectric substrates is associated with very slow growth rate of graphene and the difficult control of defect-free sample. New growth techniques, suitable dielectric substrates or unexplored experimental conditions are expected to be developed to overcome these challenges in future.