Control of layer stacking in CVD graphene under quasi-static condition

Abstract

The type of layer stacking in bilayer graphene has a significant influence on its electronic properties because of the contrast nature of layer coupling. Herein, different geometries of the reaction site for the growth of bilayer graphene by the chemical vapor deposition (CVD) technique and their effects on the nature of layer stacking are investigated. Micro-Raman mapping and curve fitting analysis confirmed the type of layer stacking for the CVD grown bilayer graphene. The samples grown with sandwiched structure such as quartz/Cu foil/quartz along with a spacer, between the two quartz plates to create a sealed space, resulted in Bernal or AB stacked bilayer graphene while the sample sandwiched without a spacer produced the twisted bilayer graphene. The contrast difference in the layer stacking is a consequence of the difference in the growth mechanism associated with different geometries of the reaction site. The diffusion dominated process under quasi-static control is responsible for the growth of twisted bilayer graphene in sandwiched geometry while surface controlled growth with ample and continual supply of carbon in sandwiched geometry along with a spacer, leads to AB stacked bilayer graphene. Through this new approach, an efficient technique is presented to control the nature of layer stacking.

Probing Bilayer Grain Boundaries in Large‐Area Graphene with Tip‐Enhanced Raman Spectroscopy

“…These observed Raman properties are in good agreement with those characteristic of AB stacking in bilayer graphene. [19] In addition, the G′ peak intensity is decreased in the region labeled E, with the emergence of an additional Raman peak at ≈1615 cm −1 (Figure 5f). This is the (5 of 6) 1603601 D′ peak, generally described as a feature of hydrogen-bonded sp 3 type defects, which depend on the growth conditions.…”

“…[19] However, the observed G′ peaks at GBs exhibit neither weaker intensity nor distinctly broader FWHM compared to the G′ peak inside a grain. Therefore, the measured GBs A, B, and C are possibly formed as a twisted bilayer with varying misorientation angle θ.…”

Recent Developments in Controlled Vapor‐Phase Growth of 2D Group 6 Transition Metal Dichalcogenides

“…According to a study of graphene growth by Subhedar et al, the close-contact geometry may trap the applied sources and flux in the interlayer space. [120] As a result, during the entire growth time, the cumulatively evaporated MO x and the leaked-in S vapor can behave quasistatically on the substrate surface and result in a higher concentration than open geometries, such as horizontal or point-to-face approaches. Furthermore, a high surface concentration aids nucleation through supersaturation, and thus the nucleation and growth of WS 2 flakes can probably be achieved on a flat surface.…”

Controlled Island Formation of Large-Area Graphene Sheets by Atmospheric Chemical Vapor Deposition: Role of Natural Camphor

“…10,23−26 In addition, various temperature conditions give an indication on the control formation of monolayer, bilayer, hexagonal structure, layer-stacking, and dendrite growth of graphene. 27,28 In this regard, the key point for the present investigation is to achieve MLG on Cu foil with a large domain size that can deliver good optical and electrical properties. An efficient, low-cost, and facile approach of using camphor as a carbon precursor has been utilized to develop an MLG sheet with a large domain size on a Cu foil and transfer it to glass and flexible polyethylene terephthalate (PET) substrates.…”