Thin metal top electrode and interface engineering for efficient and air-stable semitransparent perovskite solar cells

To find promising device architecture for air-stable as well as efficient semitransparent perovskite solar cells (PeSCs), Ag & Cu semitransparent top electrode and interfacial engineering technologies are explored in PeSCs consisting with indium tin oxide (ITO)/hole transporting layer (HTL)/CH3NH3PbI3/[6,6]-phenyl-C61 butyric acid methyl ester (PCBM)/Ag or Cu. Devices with NiOx HTL exhibits better performance than conventional poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based devices and modification of PCBM with polyethylenimine ethoxylated (PEIE) also induces improved performance. Optimized semitransparent PeSC with Cu shows superior performance, achieving a power conversion efficiency (PCE) of 11.95% and average visible transmittance (AVT) of ∼20%, and stability to Ag based device.