Research progress in synthesis of large-area single crystal graphene on copper by chemical vapor deposition

Abstract

The exceptional properties of graphene provide a promising candidate in the future electrics and photoelectronic devices. The controllable synthesis of graphene films by chemical vapor deposition is of central importance for large-scale application of high-performance graphene devices. However, grain boundaries in polycrystalline graphene films hinder the fast transportation of carriers in the material, degrading the electrical properties. Large graphene single crystals could reduce the grain boundary defects and improve the quality of graphene films. In this review, approaches of the synthesis of large-area graphene single crystals on copper substrate by chemical vapor deposition were summarized, including two main strategies as decreasing the graphene nucleation density and seamless stitching of highly-oriented graphene islands. Different realization methods, mechanism and characteristics were clarified. Several key influence factors were discussed, such as the pretreatment of substrates, the controlling of partial pressure of carbon source and the oxygen-assisted growth, etc. Finally, existing challenges of the present preparation were analyzed. The synthesis trend of large-area graphene single crystals in the future was discussed.Exploration on the growth mechanisms and kinetics of graphene single crystals help to realize their precise growth control in different environments. Developments of mass production at low cost and in-situ synthesis on diverse target substrates are the keys to wide use of graphene single crystals.

Keywords

• graphene
• single crystal
• chemical vapor deposition
• nucleation density
• seamless stitching