Sulfonate Additive Simultaneously Suppresses Interstitials and Vacancies Toward Efficient and Stable Perovskite Quantum Dot LEDs

Abstract Defect suppression via precursor additives is crucial to achieving high efficiency and stable perovskite quantum dot light‐emitting diodes (Pe‐QLEDs). Herein, a strategy using 4‐dodecylbenzenesulfonic acid (DBSA) is developed to simultaneously suppress halide interstitial and vacancy defects by tuning the crystallization process of perovskite quantum dots (Pe‐QDs) through coordinate bonding and chemical circumstance modulation, leading to faster radiative recombination and less carrier accumulation in the device. Meanwhile, the Pe‐QDs with defect suppression demonstrate higher ion migration activation energies. Thanks to the defect suppression strategy with the aid of the alkyl sulfonic group, the obtained Pe‐QDs exhibit an external quantum efficiency (EQE) of up to 20.4% and an operating lifetime of over 100 h in QLED, which is the leading performance of green Pe‐QLEDs. This work provides a strategy from a different aspect for the perovskite QLED field in improving the performance and stability of devices.