Graphene oxide (GO) has been synthesized by modified new Hummer's method with the help of Graphite flakes with sodium nitrite due to its various applications in physical, chemical, and medical sciences. The structure and morphology of GO are characterized using XRD, FTIR, RAMAN spectroscopy, and SEM. The results confirm that the synthesized material is graphene oxide (GO). The synthesized graphene oxide is used in perovskite solar cell as ETL layer.