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Abstract. This study presents a structural layer separating method using centrifugation to isolate high-quality, transparent few layer reduced graphene oxide (rGO) from thick black rGO cluster residues. The separated supernatant fractions named as layers 1–4 were drop-casted onto rigid glass and flexible Polyethylene Terephthalate (PET) substrates. High power microscopy con-firmed that the top fractions (Layer 1 and 2) yielded highly uniform, transparent, and shimmering thin films, whereas the bottom fractions (Layer 3 and 4) formed dense macroscopic aggregates on glass and PET due to aggregation of black particles on bottom of the layers. Raman spectroscopy successfully mapped the carbon fingerprints (D and G bands) against the intrinsic carbonyl stretching modes of the substrate. Electrical evaluations revealed that Layer 1 achieved the lowest base sheet resistance alongside unique, voltage-dependent charge-trapping behavior. These multi-analytical insights demonstrated that targeting the topmost centrifugal supernatant fractions provides the optimal morphological and electrical properties suitable for flexible electronics.
Keywords: Reduced Graphene Oxide, Centrifuges, Glass, Polyethylene Terephthalate (PET), High power microscope (HPM), Raman spectroscopy, Bio-sensing, Sheet resistance, Flexible.
