Comparison of Photovoltaic Performance Enhancement in BiFeO3 by Using Graphene and Carbon Nanotubes as Transparent Electrode

Enhanced photovoltaic performance of BiFeO 3 (BFO) material by utilizing graphene and carbon nanotubes (CNT) as transparent electrodes is compared for the first time. The short circuit current density and open circuit voltage are measured to be 34μA/cm 2 , 2.4μA/cm 2 , 0.27V and 0.31V by utilizing graphene and carbon nanotubes (CNT), respectively, much higher than the value reported in polycrystalline BFO. A theoretical model considering ferroelectric polarization, interface state, and energy band bending are constructed to investigate the carrier transportation behavior of the BFO solar cell. A Photochromic film is also proposed as an interesting application by using graphene/BFO/Pt solar cell as a photo detector.