Stability, electronic structure, and optical properties of protected gold-doped silver Ag_29−xAu_x (x = 0–5) nanoclusters

Abstract

In this work, we used density functional theory (DFT) and linear response time-dependent DFT (LR-TDDFT) to investigate the stability, electronic structure, and optical properties of Au-doped [AgAu(BDT)(TPP)] nanoclusters (BDT: 1,3-benzenedithiol; TPP triphenylphosphine) with x = 0-5. The aim of this work is to shed light on the most favorable doped structures by comparing our results with previously published experimental data. The calculated relative energies, ranging between 0.8 and 10 meV per atom, indicate that several doped AgAu nanoclusters are likely to co-exist at room temperature. However, only the Au-doped [AgAu(BDT)(TPP)] nanoclusters that have direct bonding between Au dopants and phosphines display an enhancement in the electronic transitions at ∼450 nm. This agrees with the main spectral absorption features that have been experimentally reported for the mixture of Au-doped silver AgAu nanoclusters. In addition, the formation of the Au-TPP bond could prevent cluster degradation starting from the detachment of the phosphine molecules, since the Au-TPP bond is stronger by ∼0.4 eV than the analogous Ag-TPP one. Thus, the results presented here show the important role of Au-TPP bonding in determining the stability and optical properties of thiolate/phosphine-protected AgAu nanoclusters.

Insight of the photoluminescence of atomically precise bimetallic nanoclusters with free electrons

“…The stability, electronic structure, and optical properties of these Au‐doped 29‐atom nanoclusters were investigated. [ 41 ] The results showed that the Au‐TPP bond was formed after the doping of Au atoms, which can prevent the degradation of the 29‐atom clusters due to the stronger bond strength of Au‐TPP than Ag‐TPP. More recently, Xie et al provided further insight into the mechanism of fluorescence enhancement of Ag 29‐x Au x nanocluster from the perspective of their geometric and electronic structures.…”

The Origin of the Photoluminescence Enhancement of Gold‐Doped Silver Nanoclusters: The Importance of Relativistic Effects and Heteronuclear Gold–Silver Bonds

“…In this regard, reliable electronic structure calculations are helpful and have successfully been used to determine the stable structures of nanoclusters . However, almost all available computational studies of Ag nanoclusters focus on low‐lying geometric structures and absorption spectra . Almost no work on the luminescence of Ag nanoclusters has been published in the past years .…”

“…[31][32][33] However,a lmost all available computational studies of Ag nanoclusters focus on low-lying geometric structures and absorption spectra. [17][18][19][20][21][22][23][34][35][36][37] Almost no work on the luminescence of Ag nanoclusters has been published in the past years. [38] Moreover, the reasons for the photoluminescence enhancement of Au-doped Ag 29 nanoclusters have not been explored computationally until now.…”

Ursache der Photolumineszenzverstärkung in Gold‐dotierten Silber‐Nanoclustern: Beiträge relativistischer Effekte und heteronuklearer Gold‐Silber‐Bindungen

“…In diesem Zusammenhang sind zuverlässige Elektronenstrukturberechnungen hilfreich und auch bereits zur Bestimmung stabiler Strukturen von Nanoclustern herangezogen worden . Fast alle verfügbaren Rechenuntersuchungen von Ag‐Nanoclustern haben sich jedoch auf energetisch günstige Geometriestrukturen und Absorptionsspektren konzentriert . Zur Lumineszenz von Ag‐Nanoclustern sind in den vergangenen Jahren so gut wie keine Arbeiten publiziert worden .…”