Table 1. Comparison of major graphene source materials preparation routes for printed interconnect applications.

Preparation method	Flake size	Defect density	Conductivity range	Scalability	Suitable applications	Ref
Liquid-phase exfoliation (LPE)	100–500 nm	Very low (pristine); ID/IG ratio typically ~0.17–0.28	~1×104 to 5×104 S/m	Highly scalable and cost-effective	High-resolution inkjet and aerosol jet printing for TFTs and antennas	[11, 20, 24]
Electrochemical exfoliation (ECE)	1–10 µm	Moderate; residual oxygen groups (C/O ~5–12) and ID/IG ~0.4–1.9	Up to ~1×105 S/m for single sheets	Scalable with fast production times	Performance electrodes for organic field-effect transistors and supercapacitors	[17, 25]
Hummers’ method (oxidative route)	0.7–100 µm	High; residual oxygen and lattice vacancies persist post-reduction	Typically,<1×104 S/m; optimized films can reach upto ~8.5×104 S/m	Most cost-effective and bulk-scalable	Bulk deposition for chemical sensors, energy storage, and thick-film composites	[19, 26, 27]

Note: The listed values are representative ranges and can vary with precursor quality, processing conditions, flake size, defect density, residual functional groups, binder content and post-treatment. Conductivity values refer to practical graphene films or printed structures, not intrinsic single-layer graphene.