Enhancing the electroluminescence of perovskite light-emitting diodes by optimizing the morphology of perovskite film to suppress leakage current

Organic-inorganic hybrid perovskites have attracted much attention due to their high color purity, low material cost, ease of tuning of bandgap, and flexible manufacture. They are considered to be a new generation of promising light-emitting materials. In this paper, an appropriate doping of polyethylene oxide (PEO) into the perovskite precursor solution acquires the high quality and low defect density of perovskite film. In addition, the passivation of perovskite grain boundaries by PEO are investigated. The perovskite light-emitting diode (PeLED) is fabricated with a structure of ITO/PEDOT:PSS/MAPbBr3/TPBi/LiF/Ag. As the doping concentration of PEO is at 10 mg/ml, MAPbBr3-PEO-based PeLEDs exhibit a maximum luminance of 4665.1cdm-2, while their external quantum efficiency (EQE) and current efficiency (CE) are also maximized to be 1.355% and 5.556cdA-1, respectively.