Investigation of optical modulated conductance effects based on a graphene oxide–azobenzene hybrid

An azobenzene (AZO) chromophore was covalently attached to graphene oxide (GO) through an amide linkage. The microstructure of the GO–AZO hybrid was characterized by microscopic and X-ray diffraction methods. An internal short-range ordered crystalline structure similar to graphite was observed. Spectroscopic evidence testified the strong electronic interactions between the AZO and GO in this GO–AZO hybrid system. Upon ultraviolet (UV) irradiation, the AZO moieties bonding on GO underwent a reversible trans–cis photoisomerization behavior. An optical modulated conductance of the GO–AZO film induced by the isomerization of the AZO chromophores was also monitored. The current showed a twofold increase after irradiation of UV light for 20 min.