▎ 摘　　要

We experimentally study the effect of different scattering potentials on the 1/f noise generated in graphene devices on silica substrates. The noise in nominally identical devices is seen to behave in two distinct ways as a function of carrier concentration, changing either monotonically or nonmonotonically. We attribute this to the interplay between long- and short-range scattering mechanisms. Water is found to significantly enhance the noise magnitude and change the type of noise behavior. By using a simple model, we show that water is a source of long- range scattering.