The use of hybrid organic−inorganic perovskites in optoelectronic applications are attracting an interest because of their outstanding characteristics, which enable a remarkable enhancement of device efficiency. However, solution-processed perovskite crystals inevitably contain defects that cause hysteresis in perovskite solar cells (PeSCs) and blinking in perovskite light-emitting diodes (PeLEDs). Here, we report remarkable beneficial effects using a new treatment based on amine-based passivating materials (APMs) to passivate the defects of methyl ammonium lead tribromide (MAPbBr3) through coordinate bonding between the nitrogen atoms and under-coordinated lead ions. This treatment greatly improved PeLEDs performance, with a luminance of 22,800 cd m-2, a current efficiency of 28.9 cd A-1, an external quantum efficiency (EQE) of 6.2 %, enhanced photoluminescence (PL), a lower threshold for amplified spontaneous emission (ASE), a longer PL lifetime and enhanced device stability. Using confocal microscopy, we observed the cessation of PL blinking in perovskite films treated with ethylenediamine (EDA) due to the passivation of the defect sites in the MAPbBr3.