Fig. 4: Performance of the PeLEDs with different ratio of EABr.

a Characterization of current density and luminance versus applied voltage. b Characterization of external quantum efficiency (EQE) versus current density. c Normalized electroluminescence (EL) spectra of perovskite LEDs with 60% EABr under increasing applied voltage. d Commission Internationale de l’Eclairage (CIE) values of the EL spectra of perovskite LEDs. e Electroluminescence images of the perovskite LEDs with different EABr.