Effect of Passivating Molecules and Antisolvents on Lifetime of Green Dion–Jacobson Perovskite Light-Emitting Diodes

Abstract

We investigated the influence of two passivating molecules containing a P�O group on the performance of quasi-2D Dion−Jacobson halide perovskite light-emitting diodes, namely, triphenylphosphine oxide (TPPO) and diphenyl-4triphenylsilylphenyl phosphine oxide (TSPO1). We found that both passivating molecules lead to increased efficiency compared to control devices, while they had opposite effects on device lifetime, with a decrease observed for TPPO and an increase observed for TSPO1. The two passivating molecules resulted in differences in energy-level alignment, electron injection, film morphology and crystallinity, and ion migration during operation. While TPPO resulted in improved photoluminescence decay times, overall higher maximum external quantum efficiency (EQE) and device lifetime were obtained for TSPO1 compared to TPPO (14.4% vs 12.4% EQE, 341 min vs 42 min T 50 ).

Surface Treatment with Tailored π-Conjugated Fluorene Derivatives Significantly Enhances the Performance of Perovskite Light-Emitting Diodes

“…Among them, the imbalanced carrier injection in the devices and the multiple defects at the surface of the perovskite film are two main factors that limit device performance. ,,, Chiefly, the imbalanced electron and hole injection induced by the charge-confined structure resulted in high Auger recombination rates and the biased distribution of the radiative recombination region tended to favor the side with weak carrier transport ability. − Additionally, the existence of multiple defects, including vacancy defects and under-coordinated lead cations (Pb 2+ ), on the surface of perovskite films frequently annihilates hydrazine in nonradiative recombination. , Consequently, rectifying imbalances in charge transport and passivating defects at the film surface emerge as strategic approaches for enhancing Pero-LEDs performance. To realize this objective, strategic functional groups, such as phosphine oxide (PO), , carbonyl (CO), , and halogens (−X), , have been intricately combined with alkanes, , fluorenes, , and thiophene , to fabricate innovative multifunctional molecules. These synthesized molecules are utilized to diminish the defect state concentration at the surface of perovskite films and enhance Pero-LEDs performance.…”