Enhanced spectral stability of blue perovskite light-emitting diodes via multidentate amine-based ligand

Abstract

Compared with highly efficient green, red, and near-infrared perovskite light-emitting diodes (PeLEDs), the performance of blue PeLEDs is still unsatisfactory due to the serious spectral instability issue at high working voltages. In this work, a multidentate amine-based ligand with four amino groups is utilized to achieve spectral stable blue quasi-2D PeLEDs. As a result, the optimized quasi-2D perovskite films exhibit stable photoluminescence spectra under continuous UV illumination and heating. Finally, the blue quasi-2D PeLEDs emitting at 478 nm with the peak external quantum efficiency up to 4.8% are achieved. Meanwhile, there is no obvious peak shift of the electroluminescence spectral under high external working voltages, exhibiting excellent spectral stability. The findings in this work confirm the validity of this strategy, providing a strategy to achieve steady blue PeLEDs.