Reduced Graphene Oxide/Copper Phthalocyanine Composite and Its Optoelectrical Properties

Reduced graphene oxide (RGO) composites containing tetrasulfonate salt of copper phthalocyanine (TSCuPc) are fabricated through the reduction of graphene oxide in the presence of water-soluble TSCuPc. The interaction between RGO monolayer and TSCuPc is investigated using ultraviolet-visible (UV-vis) spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The composites of electron donor (TSCuPc) and acceptor (RGO) are successfully incorporated in devices, and their optoelectronic properties are studied. Compared with RGO films, the RGO/TSCuPc composite films have lower conductivity (dark current) but much higher photoconductivity and photoresponsivity because of the presence of donor/acceptor materials and large donor/acceptor (D/A) interfaces for charge generation. The optoelectrical properties of the composite film can be improved by thermal annealing and optimizing the TSCuPc content. The RGO/TSCuPc composite films fabricated by the solution processing method could be used as large-area optoelectronics devices.