Nonlinear optical absorption and asymmetric charge carrier conduction in chemical vapor deposited single-layer graphene

Abstract

In this work, we report the nonlinear optical absorption and asymmetric charge carrier conduction in single layer graphene films deposited by chemical vapor deposition (CVD) technique on copper foils with pretreated surface. XRD texture and pole figure analysis of the substrate are utilized for the visualization of the effect of the pretreatment on the substrate. The synthesised graphene is employed as a channel layer in a back gated field-effect transistor and the asymmetric behavior of charge carriers is analyzed. Nonlinear optical response of graphene is recorded after transferring it onto a quartz substrate. Open aperture Z-scan technique yields a nonlinear absorption coefficient of 5.34 × 106 cm GW−1. The film exhibits saturable absorption in the visible range with a saturation intensity as low as 0.134 GW cm−2.