Nano Research · 2014 · 232 citations · 43 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsOptoelectronicsSemiconductor MaterialsCarrier TransportPhotovoltaic DevicesPhotovoltaic MaterialsSemiconductor PhysicsSolar Cell MaterialsSolar CellsCarrier DiffusionCharge Carrier MobilityCharge DiffusionHeterojunction Solar CellsInterfacial EngineeringOrganic-inorganic Hybrid PerovskitesPerovskite SemiconductorsPerovskite Solar Cells
We demonstrate that charge carrier diffusion lengths of two classes of perovskites, CH3NH3PbI3−x Cl x and CH3NH3PbI3, are both highly sensitive to film processing conditions and optimal processing procedures are critical to preserving the long carrier diffusion lengths of the perovskite films. This understanding, together with the improved cathode interface using bilayer-structured electron transporting interlayers of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/ZnO, leads to the successful fabrication of highly efficient, stable and reproducible planar heterojunction CH3NH3PbI3−x Cl x solar cells with impressive power-conversion efficiencies (PCEs) up to 15.9%. A 1-square-centimeter device yielding a PCE of 12.3% has been realized, demonstrating that this simple planar structure is promising for large-area devices.
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