Abstract
Graphene possesses excellent chemical stability, high carrier mobility, and unique optoelectrical properties at atomic level, which was considered as a promising material to replace Si in semiconductor industry. In this study, the chemical vapor deposition method was adopted to grow N-doped graphene on the electropolished Cu foil, followed by transferring the as-synthesized graphene to polyethylene terephthalate substrate for the fabrication of flexible transparent field-effect-transistor. Graphene growth and transferring were characterized using Raman spectrum, field-emission scanning electron microscopy, and optical microscopy, and thickness and absorptace were measured using atomic force microscopy and UV-visible spectrometer, respectively. Carrier mobilities of the fabricated FET with/without bending were measured using a multi-probe system. The results indicate that the thickness, absorptance, and carrier mobility of the N-doped graphene were 0.4~0.8 nm, 2.34 %, and 16200 cm2/V∙s, respectively. The carrier mobility of the bended FET was not significantly affected while the curvature radius higher than 1.0 cm. We also demonstrated that the electropolish technique was beneficial for improving the electrical performances of the graphene-based FET with 2 or 3-times higher than those without electropolish treatment. Furthermore, the N-type character was still remained even the N-doped graphene FET was exposed in the air atmosphere for one month, showing the highly air-stable of the N-doped graphene FET.