The electron transport layer (ETL) plays a crucial role in facilitating electron extraction and inhibiting recombination in perovskite solar cells. Reduced graphene oxide (RGO) is a potential complement to the common ETL material TiO2 thanks to its excellent electrical conductivity and mobility and the suitability for scalable, low-temperature solution-processed deposition. RGO powder is synthesized through microwave-assisted hydrothermal method, and various amounts of o-phenylenediamine (OPD) are added into the precursor to create Nitrogen-doped RGO of different doping levels. The as-synthesized RGO samples characteristics are examined by XRD, XPS and Raman spectroscopy. The perovskite layer of CH3NH3PbI3 is deposited on RGO and TiO2 using a two-step spin coating process, and the as-deposited perovskite characteristics are examined through photoluminescence and UV-Vis spectroscopy. Finally, photovoltaic performance measurements of completed RGO-integrated devices is conducted under illumination of 1 Sun AM 1.5G sunlight simulator.

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