Gold nanoclusters with bright near-infrared photoluminescence

0489710 - ÚOCHB 2019 RIV GB eng J - Journal Article
Pramanik, Goutam - Humpolíčková, Jana - Valenta, J. - Kundu, P. - Bals, S. - Bouř, Petr - Dračínský, Martin - Cígler, Petr
Gold nanoclusters with bright near-infrared photoluminescence.
Nanoscale. Roč. 10, č. 8 (2018), s. 3792-3798. ISSN 2040-3364. E-ISSN 2040-3372
R&D Projects: GA ČR(CZ) GA16-05935S; GA MŠMT(CZ) LTC17012; GA ČR(CZ) GA18-12533S
Institutional support: RVO:61388963
Keywords : aggregation-induced emission * excited state behavior * quantum yield
OECD category: Physical chemistry
Impact factor: 6.970, year: 2018
http://pubs.rsc.org/en/content/articlehtml/2018/nr/c7nr06050e

The increase in nonradiative pathways with decreasing emission energy reduces the luminescence quantum yield (QY) of near-infrared photoluminescent (NIR PL) metal nanoclusters. Efficient surface ligand chemistry can significantly improve the luminescence QY of NIR PL metal nanoclusters. In contrast to the widely reported but modestly effective thiolate ligand-to-metal core charge transfer, we show that metal-to-ligand charge transfer (MLCT) can be used to greatly enhance the luminescence QY of NIR PL gold nanoclusters (AuNCs). We synthesized water-soluble and colloidally stable NIR PL AuNCs with unprecedentedly high QY (similar to 25%) upon introduction of triphenylphosphonium moieties into the surface capping layer. By using a combination of spectroscopic and theoretical methods, we provide evidence for gold core-to-ligand charge transfer occurring in AuNCs. We envision that this work can stimulate the development of these unusually bright AuNCs for promising optoelectronic, bioimaging, and other applications.
Permanent Link: http://hdl.handle.net/11104/0284075