Lamination-produced semi-transparent/flexible perovskite solar cells with doped-graphene anode and cathode

Abstract Semi-transparent flexible perovskite solar cells (FPSCs) are highly attractive for effective use of solar energy in many areas such as building- and vehicle-integrated photovoltaics. High power conversion efficiency (PCE) of perovskite solar cells is achieved mainly by using transparent conductive oxide electrodes, which are unsuitable for FPSCs. Here, we first report semi-transparent and high-aperture FPSCs with anode/cathode electrodes fabricated by doping of graphene (GR) with bis (trifluoromethanesulfonyl)-amide (TFSA) and triethylenetetramine (TETA), respectively. The FPSCs are fabricated by laminating the polyethylene terephthalate (PET)/TETA-doped GR (TETA-GR)/ZnO/MAPbI3/poly-triarylamine and the PEDOT:PSS/TFSA-doped GR (TFSA-GR)/PET stacks. PCEs of 10.56/10.73% are obtained by illumination at the TFSA-GR/TETA-GR sides of the FPSCs with an active area of 100 mm2, respectively. The PCE is further enhanced to 10.96/11.16% by adding Ag reflectors at the top/bottom of the FPSCs, respectively. In addition, the PCE is maintained at 70% or more of its original value even after 1000 bending cycles at a bending radius of 8 mm, promising for practical applications of the FPSCs as next-generation semi-transparent solar energy power sources.