Study on the Absorption Coefficient of Reduced Graphene Oxide Dispersion

Light absorption of graphene plays an important role in optoelectronic applications. In this work, a series of reduced graphene oxide (RGO) dispersions containing flakes with various configurations are prepared, and their optical absorption coefficients are investigated. Our results suggest that the lateral size distribution, the mean number of layers per flake and the functional groups on RGO are all important factors influencing the absorption coefficient. We find the dispersion with a larger amount of small flakes (<= 600 nm), as well as less layers per flake, gives a smaller absorption coefficient at 660 nm. Essentially, functional groups grafted on graphene flakes promote an eminent role in the absorption coefficient.