Polymeric nanocomposites based on UV in situ reduced graphene oxide were developed in order to enhance the electrical conductivity of polymeric matrices for the realization of highly efficient solid-state hybrid solar cells based on organometal trihalide perovskite absorbers. Graphene is a 2-D single layer of sp2-bonded carbon atoms characterized by high specific surface area, Young's modulus, thermal stability, mobility of charge carriers and plus fascinating transport phenomena such as the quantum Hall effect. Among several developed methods to prepare graphene, including chemical vapor deposition (CVD) and mechanical exfoliation, the chemical reduction of graphene oxide (GO) is regarded as the most promising for future implementation in large-scale production. In this work, a GO prepared by a modified Hummers method was used and reduced by a green method based on UV treatment in inert …