B Rezaei - PhD student at chemistry department of Amirkabir university of technology, Tehran, Iran
N Yousefi - Master student at polymer department of Amirkabir university of technology, Tehran, Iran
M Kian Pishe - Bachelor student at polymer department of Amirkabir university of technology, Tehran, Iran
F Afshar Taromi - professor at polymer department of Amirkabir university of technology, Tehran, Iran

Three different methods, Hummers method, modified Hummers method and improved Hummers method were used for the preparation of graphene oxide (GO). Among these methods, improved Hummers method gave the best oxygen-containing functional groups and the distance between the sheets was more than graphene oxide prepared by two other methods. Poly (ethylene terephthalate) was functionalize by chemical agents and graphene oxide was spin coated on the substrate, due the chemical interaction between carboxylic acid, hydroxyl and epoxy groups, with hydroxyl groups on PET, the stability after bending was improved and reduction by hydrazine vapor was used to reduce GO. FTIR, XRD, contact angle, Raman and SEM were used for characterization

graphene oxide, reduction, Hummers method, polymer solarcell