Stabilizing Perovskite Light-Emitting Diodes by Alternating Current

Abstract

Ion migration is inevitable for perovskite light-emitting diodes (PeLEDs) operating under a constant direct current (DC) electric field, significantly undermining device stability. Herein, a straightforward and effective strategy is presented for boosting the lifetime of PeLEDs by employing an alternating current (AC)-driving mode. The impact of driving mode on device performance is investigated, achieving a record external quantum efficiency (EQE) of 14.9% under AC-driving mode with negligible efficiency roll-off (EQE >13.5%) across a wide range of current densities (1 to 400 mA cm⁻²). Notably, the effectively suppressed ion migration is demonstrated in AC-driving mode, resulting in a remarkable 40-fold increase in operational lifetime (T₅₀) compared to the DC-driving mode. This enhancement is particularly pronounced in mixed-halide PeLEDs (e.g., FAPbI₂Br), where the challenging issue of spectral drift due to ion migration has been effectively resolved.