Fig. 3

Performance of CsPbCl0.9Br2.1 perovskite light-emitting diodes (LEDs) with different ratios of phenylethylammonium bromide (PEABr). a Perovskite LED architecture and energy level diagram for different layers of the device. b Characterization of current density and luminance versus voltage. The solid lines and lines with dots correspond to the luminance and the current density, respectively. c Characterization of external quantum efficiency (EQE) versus current density. d Electroluminescence (EL) spectra of perovskite LEDs. e Commission Internationale de l’Eclairage (CIE) values of the EL spectra of perovskite LEDs