Thiophene Derivatives as Ligands for Highly Luminescent and Stable Manganese-Doped CsPbCl3 Nanocrystals

Abstract

Ligands on the surface of perovskite nanocrystals are important to stabilize the nanocrystal structure. However, the research of ligands on Mn2+ ion-doped CsPbCl3 nanocrystals (Mn: CsPbCl3 NCs), a promising candidate family for the lightning community, is relatively rare. Here, we demonstrate a new ligand modification strategy for preparing high-quality Mn: CsPbCl3 NCs by a simple hot-injection method. Thiophene derivative, for the first time, is applied as ligands for perovskite nanocrystals. The new ligands of thiophene derivatives passivate defects on the surface of NCs and enhance optical properties, originating from the sulfur in thiophene additives binding to the uncoordinated lead ions. The photoluminescence quantum yield of the modified Mn: CsPbCl3 NCs is 93% in comparison with 46% of the pristine counterparts, whose value is the highest to date for ligand-modified Mn: CsPbCl3 NCs. Meanwhile, the thermal, storage, and purification stability are also significantly improved. The performance of related LEDs is also investigated.

Multifunctional Short-Chain 2-Thiophenealkylammonium Bromide Ligand-Assisted Perovskite Quantum Dots for Efficient Light-Emitting Diodes

“…To address the above issues and develop a multifunctional ligand that can both achieve surface passivation and improve carrier transport, we investigated thiophene functional groups with electron-donating properties. The high polarization of its sulfur atom causes looser binding of valence π electrons to the aromatic ring, resulting in higher charge mobility. , Additionally, the S atom in the thiophene ring can coordinate with uncoordinated Pb 2+ to passivate defects. , Therefore, by designing ligand molecules and using this characteristic, it is possible to achieve a multifunctional ligand.…”

“…30,31 Additionally, the S atom in the thiophene ring can coordinate with uncoordinated Pb 2+ to passivate defects. 32,33 Therefore, by designing ligand molecules and using this characteristic, it is possible to achieve a multifunctional ligand.…”

2,2′-Bipyridine-4,4′-dicarboxylic Acid-Mediated Surface Engineering of Mn-Doped CsPbCl3 Perovskite Nanocrystals

“…Many metal ions and additives have been employed to enhance the PLQY and energy transfer of Mn-doped CsPbCl 3 PNCs. − Luo et al reported an interesting finding: tuning of dual-color emission of Mn-doped CsPbCl 3 PNCs by post-synthesis treatment with a series of sulfonate ligands; however, the PLQY and stability of the synthesized PNCs after passivation were not studied . Wang et al demonstrated that adding 3-thienylboronic acid during synthesis can improve the PLQY and thermal, self, and purification stabilities of Mn-doped CsPbCl 3 …”

“…28 Wang et al demonstrated that adding 3-thienylboronic acid during synthesis can improve the PLQY and thermal, self, and purification stabilities of Mn-doped CsPbCl 3 . 29 Photoluminescence is a surface phenomenon; thereby, surface treatment is a promising technique for producing defect-free PNCs with improved optical characteristics. Several reports are available on the surface treatment of PNCs with various organic additives such as trioctylphosphine (TOP), 30,31 trioctylphosphine oxide (TOPO), 32 benzoic acid, 33 2,2′iminodibenzoic acid, 11 zwitterions, 34 octyl phosphonic acid, 35 dodecane thiol, 36 thiocyanate, 37 thiosulfate, 38 and tetrafluoroborate.…”