Low-frequency noise in irradiated graphene FETs

We present a quantitative analysis of the low-frequency noise in irradiated monolayer graphene. In this study, we repeatedly irradiate a back-gated graphene transistor with argon ions at 90 eV and measure its low-frequency noise and channel conductivity after each irradiation. Our results indicate that the noise amplitude decreases monotonically with the increasing density of vacancy defects. The combination of our low-frequency noise measurements and carrier transport studies reveals that the mobility fluctuation model can explain this observation and that the density of vacancy defects, the density of charged impurities, and the mean free path of charge carriers determine the noise amplitude.