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Hidden reaction pathways inform additive engineering for perovskite LEDs

Published: 10/14/2026, 12:00 AM

Nature volume 658, pages 629–635 (2026) Cite this article Perovskite light-emitting diodes (PeLEDs) have emerged as a promising class of solution-processed light-emitting devices, combining high efficiency with facile fabrication1,2,3,4,5. Amino-acid-based molecular additives are widely used to regulate crystallization and suppress defects in perovskite thin films6,7,8, yet these molecules are chemically reactive in precursor solutions, in which their transformations and products remain poorly understood. Here we resolve and control the hidden solution-phase chemistry of a ubiquitous additive, 5-aminovaleric acid (5AVA), whose solution-phase reactivity has remained unclear6,9,10,11,12,13,14,15. We show that 5AVA undergoes competing in situ reactions during precursor preconditioning, yielding two chemically and functionally distinct products: a beneficial organoamidinium zwitterion and a detrimental Lewis-base lactam. By explaining this reaction dichotomy and establishing targeted reaction-pathway control, we selectively use the beneficial species. Direct synthesis and incorporation of the purified zwitterion decouple its intrinsic passivation function from confounding by-products, yielding perovskite films with a near-unity mean peak photoluminescence quantum yield (PLQY) of 97.2% and PeLEDs with a champion external quantum efficiency (EQE) of 37.1%, alongside a mean peak EQE of 32.8%. Finally, we demonstrate that this reaction-pathway control concept can be extended to further additive chemistries and emission colours, highlighting its potential as a chemistry-driven strategy for rational additive design in PeLEDs. This is a preview of subscription content, access via your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription Prices may be subject to local taxes which are calculated during checkout All data supporting the findings of this study are available in the article, its Extended Data and its Supplementary Information. Source data are provided with this paper. Kim, J. S. et al. Ultra-bright, efficient and stable perovskite light-emitting diodes. Nature 611, 688–694 (2022). Article CAS PubMed Google Scholar Liu, X.-K. et al. Metal halide perovskites for light-emitting diodes. Nat. Mater. 20, 10–21 (2021).