Reducing the impact of Auger recombination in quasi-2D perovskite light-emitting diodes

Abstract

Abstract Rapid Auger recombination represents an important challenge faced by quasi-2D perovskites, which induces resulting perovskite light-emitting diodes’ (PeLEDs) efficiency roll-off. In principle, Auger recombination rate is proportional to materials’ exciton binding energy ( E b ). Thus, Auger recombination can be suppressed by reducing the corresponding materials’ E b . Here, a polar molecule, p -fluorophenethylammonium, is employed to generate quasi-2D perovskites with reduced E b . Recombination kinetics reveal the Auger recombination rate does decrease to one-order-of magnitude lower compared to its PEA + analogues. After effective passivation, nonradiative recombination is greatly suppressed, which enables resulting films to exhibit outstanding photoluminescence quantum yields in a broad range of excitation density. We herein demonstrate the very efficient PeLEDs with a peak external quantum efficiency of 20.36%. More importantly, devices exhibit a record luminance of 82,480 cd m −2 due to the suppressed efficiency roll-off, which represent one of the brightest visible PeLEDs yet.