High performance organo-lead halide perovskite light-emitting diodes via surface passivation of phenethylamine

One of the organometal halide perovskite materials, i.e. methylammonium lead bromide (MAPbBr₃), possesses interesting and incredible physicochemical properties, and shows great promising in light-emitting device. However, the poor morphology and high defect density properties of MAPbBr₃ films limit the performance of perovskite light-emitting diodes (PeLEDs). Here, high efficiency PeLEDs based on MAPbBr₃ is demonstrated by the incorporation of phenethylamine (PEA). We find that the introduction of PEA into the precursor of MAPbBr₃ reduces the grain size and increases the coverage of MAPbBr₃ films. In addition, it also passivates the surface defects of the grains, which all lead to high photoluminescence efficiency. In order to promote the charge injection into the MAPbBr₃ grains, suppress the exciton quenching at the interface of perovskite film and hole transporting layer (HTL)/electron transporting layer (ETL), the device structure of “insulator-perovskite-insulator” is employed to further improve the performance of the PeLEDs. Under optimized ratio of MA and PEA, a maximum current efficiency 9.81 cd A⁻¹ is achieved. Our work presents an facile and robust route for high performance PeLEDs.