You should explain in some more detail what you mean precisely. For now, if you have a bilayer Bernal graphene, then it should not matter how you have arrived at it. If, on the other hand, what you have does not display the characteristic experimental properties of a bilayer Bernal graphene, then your adopted approach has not produced such bilayer. Incidentally, are you aware of the work by Yan et al. [1]?

[1] K Yan et al., Nano Lett. 11, 1106 (2011).

Article Formation of Bilayer Bernal Graphene: Layer-by-Layer Epitaxy...

@Behnam Farid Sir,

Suppose I am taking two perspectives,

1. Formation of bernal stacked bilayer graphene via CVD or via mechanical exfoliation.

2. Mechanically stacking two graphene monolayers vertically somehow, as to get bernal arrangement of lattice.

Now considering the van der waal forces in both the cases in between the monolayers, do both the perspectives yield the same optical and electrical properties?

Mukesh Pandey : Both approaches have been successfully realised. For CVD, see [1] in my earlier comment on this page as well as [1] below. For obtaining Bernal bilayers of graphene through exfoliation from graphite, see [2] (see the section Method Summary herein). In fact, a third approach, based on an 'aligned transfer of two single-crystalline monolayers' of graphene, has also been successfully realised [3].

[1] Y Hao et al., Nature Nanotechnology 11, 426 (2016).

Article Oxygen-activated growth and bandgap tunability of large sing...

[2] Y Zhang et al., Nature 459, 820 (2009).

Article Direct Observation of a Widely Tunable Bandgap in Bilayer Graphene

[3] VL Nguyen et al., Adv. Mater. 28, 8177 (2016).

Article Wafer-Scale Single-Crystalline AB-Stacked Bilayer Graphene

Behnam Farid Sir, thanks a lot with lots of well wishes.

Mukesh Pandey : My pleasure.