Direct Synthesis of Large-Area Graphene on Insulating Substrates at Low Temperature using Microwave Plasma CVD

Abstract

With a combination of outstanding properties and a wide spectrum of applications, graphene has emerged as a significant nanomaterial. However, to realize its full potential for practical applications, a number of obstacles have to be overcome, such as low-temperature, transfer-free growth on desired substrates. In most of the reports, direct graphene growth is confined to either a small area or high sheet resistance. Here, an attempt has been made to grow large-area graphene directly on insulating substrates, such as quartz and glass, using magnetron-generated microwave plasma chemical vapor deposition at a substrate temperature of 300 °C with a sheet resistance of 1.3k Ω/□ and transmittance of 80%. Graphene is characterized using Raman microscopy, atomic force microscopy, scanning electron microscopy, optical imaging, UV–vis spectroscopy, and X-ray photoelectron spectroscopy. Four-probe resistivity and Hall effect measurements were performed to investigate electronic properties. Key to this report is the use of 0.3 sccm CO 2 during growth to put a control over vertical graphene growth, generally forming carbon walls, and 15–20 min of O 3 treatment on as-synthesized graphene to improve sheet carrier mobility and transmittance. This report can be helpful in growing large-area graphene directly on insulating transparent substrates at low temperatures with advanced electronic properties for applications in transparent conducting electrodes and optoelectronics.

Quantifying Mn diffusion through transferred versus directly-grown graphene barriers

“…Translating these performance enhancements to functional substrates at wafer scale will require direct graphene synthesis approaches on the substrate of interest. For example, CVD approaches using small molecules [23], activated precursors [24], or plasmaenhanced CVD processes [25][26][27] show promise for reducing the graphene synthesis temperature, and may be a route for graphene growth directly on GaAs and other technologically important compound semiconductors.…”

Review of fabrication methods of large-area transparent graphene electrodes for industry

“…This allows lower growth temperatures and the copper foam shielding the graphene from ion bombardment and smoothening the electric field. A RF plasma power of 80 [136]. Low amounts of CO 2 (0.3 sccm) decreased sheet resistance of the graphene while only slightly decreasing transmittance, while O 3 improved both parameters by cleaning the graphene surface.…”

Advances in Microwave‐Enhanced Chemical Vapor Deposition for Graphene Synthesis

“…[33] Copyright 2019, Spring Nature] (e, f) the Raman spectrum of graphene synthesized without and with CO 2 , [Reproduced with permission. [35] Copyright 2019, American Chemical Society induced H 2 and Ar plasma for 20 min to form Cu particles, when CH 4 was introduced to grow graphene for 5 min. The flow rates of H 2 , Ar, and CH 4 were 400, 30, 10 sccm, and the total gas pressure was 3990 Pa.…”

“…Copyright 2013, Elsevier] (d) of PG, NG1, NG2, NG3 [Reproduced with permission [33]. Copyright 2019, Spring Nature] (e, f) the Raman spectrum of graphene synthesized without and with CO 2 , [Reproduced with permission [35]. Copyright 2019, American Chemical Society…”