Chemical vapor deposition growth of 5 mm hexagonal single-crystal graphene from ethanol

Abstract

a b s t r a c tWe show that graphene single crystals as large as 5 mm can be synthesized from ethanol via chemical vapor deposition (CVD). Key conditions for the successful reduction in nucleation density are extremely low partial pressure of ethanol vapor and pre-oxidation of Cu substrates. The resulting graphene flakes are predominantly homogeneous single-layer hexagons, as characterized by Raman spectroscopy and selected area electron diffraction. However, the edge of ethanol produced graphene shows an armchair feature, suggesting a possible different mechanism from conventional methane CVD.

Understanding and Controlling Cu-Catalyzed Graphene Nucleation: The Role of Impurities, Roughness, and Oxygen Scavenging

“…19 We do not observe a measurable increase in graphene growth rate with our oxidation methods under our conditions. 43 Either way, the following question arises: what causes this significant change in GND for method III?…”

“…Different CH 4 flow rates ( V CH 4 ) are shown as solid lines for the use of 0.1% diluted CH 4 in Ar. Literature (Wu16, 54 Wu15, 18 Eres, 29 Wang14, 55 Chen13, 37 Chen15, 43 Lin, 56 Miseikis, 42 Zhou, 14 and Yan12 57 ) values are included for graphene growth on polycrystalline foil and homogeneous precursor exposure, with the exception of Wu15, 18 where local precursor feeding was used. (b) A Cu foil after graphene growth performed with 20 sccm CH 4 (0.1% diluted in Ar) and a growth time of 8 h with BO + Ar treatment (to visualize graphene grains directly on the Cu foil, it was placed on a hot plate at 250 °C for 1 min 58 ).…”

Rapid Growth of Large Single‐Crystalline Graphene via Second Passivation and Multistage Carbon Supply

“…[ 18,24 ] In addition, passivation of the active sites on copper foil prior to the graphene growth, such as oxygen exposure, is expected to enable graphene nucleation in a controllable manner. [ 12,16,27,28 ] These passivators could nevertheless react with the reducing agent (e.g., the reaction between oxygen and hydrogen) to cause the passivated sites to regain their catalytic ability for new nucleation.…”

Carbon Dots Dispersed on Graphene/SiO2/Si: A Morphological Study

“…Graphene is the archetypal two‐dimensional (2D) material attracting a constant interest because of its stability, combined with excellent electrical, mechanical, and optical properties . Among the graphene synthesis methods, the chemical vapor deposition (CVD) on metal foils is a promising technique to deliver large‐area films with controlled properties for many applications . Perhaps more than the growth process itself, the transfer of atom‐thick CVD‐Gr sheets from the growth substrate to the target substrate is a crucial aspect of the fabrication of any graphene‐based device.…”