The Way towards Ultrafast Growth of Single‐Crystal Graphene on Copper

Abstract

The exceptional properties of graphene make it a promising candidate in the development of next‐generation electronic, optoelectronic, photonic and photovoltaic devices. A holy grail in graphene research is the synthesis of large‐sized single‐crystal graphene, in which the absence of grain boundaries guarantees its excellent intrinsic properties and high performance in the devices. Nowadays, most attention has been drawn to the suppression of nucleation density by using low feeding gas during the growth process to allow only one nucleus to grow with enough space. However, because the nucleation is a random event and new nuclei are likely to form in the very long growth process, it is difficult to achieve industrial‐level wafer‐scale or beyond (e.g. 30 cm in diameter) single‐crystal graphene. Another possible way to obtain large single‐crystal graphene is to realize ultrafast growth, where once a nucleus forms, it grows up so quickly before new nuclei form. Therefore ultrafast growth provides a new direction for the synthesis of large single‐crystal graphene, and is also of great significance to realize large‐scale production of graphene films (fast growth is more time‐efficient and cost‐effective), which is likely to accelerate various graphene applications in industry.

Vapor‐phase growth of high‐quality wafer‐scale two‐dimensional materials

“…As suppressing nucleation is mostly achieved by decreasing the concentration of precursors, it will result in a low growth rate and a long growth time. The ultrafast growth can make the growth process time‐ and cost‐efficient, which is expected to accelerate practical applications . Therefore, improving the growth rate is a crucial and significant goal toward the synthesis of high‐quality wafer‐scale 2D materials .…”

“…The ultrafast growth can make the growth process time-and cost-efficient, which is expected to accelerate practical applications. 25 Therefore, improving the growth rate is a crucial and significant goal toward the synthesis of high-quality wafer-scale 2D materials. 108 The kinetics of the CVD process has important influences on the growth rate.…”

“…Therefore, one way for the growth of high‐quality wafer‐scale 2D materials is to reduce the nucleation density, making the nucleus to grow with enough space and eventually evolve into a large crystal. A straightforward route is to grow up from a single seed, which is similar to silicon ingot growth . Another thoroughgoing approach is to make the multinucleation domains with identical orientation seamless coalesce into a wafer‐scale single‐crystal film, which can usually be achieved on a single‐crystal substrate or liquid substrate .…”

“…A straightforward route is to grow up from a single seed, which is similar to silicon ingot growth. 4,10,25 Another thoroughgoing approach is to make the multinucleation domains with identical orientation seamless coalesce into a wafer-scale single-crystal film, which can usually be achieved on a single-crystal substrate or liquid substrate. 5,11,26,27 The third effective one is the evolutionary selection growth (ESG) that can eliminate the formation of undesired seeds to get largearea single-crystal 2D materials, even on a polycrystalline substrate.…”

Atomic Layer Deposition Alumina‐Mediated Graphene Transfer for Reduced Process Contamination

“…Chemical vapor deposition (CVD) of graphene on copper substrates has progressed extensively over recent years, to the point where high‐quality graphene crystals can readily be synthesized . However, fabricating electronic devices from these crystals typically requires transfer onto dielectric substrates, with additional lithographic and etching fabrication steps required for obtaining the final device.…”