Heteroatom doped reduced graphene oxide paper for large area perovskite solar cells

Heteroatom (boron) doped reduced graphene oxide (B-rGO) papers were prepared by the simple self-assembly process of graphene oxide through the deoxygenation in argon atmosphere at 400 degrees C. The phase purity and crystallinity of the B-rGO paper were studied by X-ray diffraction analysis. The wrinkled paper-like morphology was analyzed by scanning electron microscopy (SEM) and the homogeneity by the elemental mapping. The binding energy states of the B-rGO were confirmed by X-ray photoelectron spectroscopy. The shift in zeta potential values also confirms the heteroatom doping in the rGO paper. From the Raman spectra it was observed that the incorporation of boron into the rGO paper exhibits an improved conductivity and mobility. The current-voltage (J-V) characteristics revealed that the B-rGO paper can be effectively used as a hole transport material (HTM) for perovskite solar cells (PSCs). The largest conversion efficiency of 8.96% was achieved for the FTO/TiO2/CH3NH3PbI3/B-rGO/FTO sandwich structure with an active area of 1 cm(2).