Electrical Characteristics of Top-Gated Graphene Field Effect Transistors Fabricated on Stainless Steel (STS) Substrate

Top-gated Graphene transistors with Al₂O₃ gate-dielectric on the flexible stainless steel substrate have been demonstrated. Graphene was synthesized on copper foil using a chemical vapor deposition method and transferred onto the stainless steel substrate by wet transfer technique. The stainless steel substrate was polished by chemical mechanical polishing method and the spin-on-glass layer was coated on the surface to improve the surface roughness. The average surface roughness R _a was as low as 5.9 nm from the AFM measurement. The measured hole and electron mobilities from the current–voltage characteristics at room temperature were calculated as high as 310 and 45 cm²/Vs, respectively. In addition, the effect of surrounding temperature up to 355 K on the electrical variations was investigated. The mobility was inversely proportional to the temperature with negligible hysteresis where the temperature coefficient was calculated as low as −0.65 %/K.