▎ 摘 要
Polycrystalline copper (Cu) foil is widely used as catalytic substrate for graphene growth in chemical vapor deposition (CVD) technique. The surface properties of the Cu foil strongly affect the growth behavior and final quality of CVD-grown graphene. The effect of pretreatment of Cu foil using four different solutions (acetone, acetic acid, HCl and HNO3) on the graphene growth held in atmospheric pressure CVD and its subsequent impact on electrical and optical properties are investigated. Natural camphor is used as the solid carbon precursor. The surface characteristics before and after the growth are studied using scanning electron microscopy and atomic force microscopy. The pretreatment conditions of Cu and the growth of graphene from camphor were correlated using Raman spectroscopy, optical and electrical characteristics. Our findings suggest that HCl-pretreated Cu foil exhibited large domain, uniform coverage of the transferred graphene with excellent optical (> 93% at 550 nm) and electrical properties (sheet resistance of 861 +/- 40 Omega/sq), with promisingly low RMS value of roughness (38 nm). The pretreatment process improved the quality of graphene by removing the surface impurity particles and surface native oxides. A Schottky junction diode of graphene/n-silicon is fabricated by transferring the graphene to SiO2/Si substrate under dark and illuminated conditions is also demonstrated to establish its potential in micro- and opto-electronics.