Solvent-mediated assembly of atom-precise gold–silver nanoclusters to semiconducting one-dimensional materials

Abstract

Bottom-up design of functional device components based on nanometer-sized building blocks relies on accurate control of their self-assembly behavior. Atom-precise metal nanoclusters are well-characterizable building blocks for designing tunable nanomaterials, but it has been challenging to achieve directed assembly to macroscopic functional cluster-based materials with highly anisotropic properties. Here, we discover a solvent-mediated assembly of 34atom intermetallic gold-silver clusters protected by 20 1-ethynyladamantanes into 1D polymers with Ag-Au-Ag bonds between neighboring clusters as shown directly by the atomic structure from single-crystal X-ray diffraction analysis. Density functional theory calculations predict that the single crystals of cluster polymers have a band gap of about 1.3 eV. Fieldeffect transistors fabricated with single crystals of cluster polymers feature highly anisotropic p-type semiconductor properties with ≈1800-fold conductivity in the direction of the polymer as compared to cross directions, hole mobility of ≈0.02 cm 2 V −1 s −1 , and an ON/OFF ratio up to ≈4000. This performance holds promise for further design of functional cluster-based materials with highly anisotropic semiconducting properties.

Ligand-protected gold/silver superatoms: current status and emerging trends

“…9b). 114 The conductivity along the polymer chain (1.49 × 10 -5 S/m) was 1800 times higher than that along the interchain direction. The conductivity of the (AuAg) 34 polymer is 1-3 orders of magnitude higher than that of a 1D polymer of Au 15 (8e) linked by weak interligand interactions.…”

One-, Two-, and Three-Dimensional Self-Assembly of Atomically Precise Metal Nanoclusters

“…Use of the alloying effect. At present, there are few examples in which alloy NCs are connected to form CSs [ 142 , 143 , 146 ]. Mixing different elements leads to NCs with physical/chemical properties and functions that are different from those of monometal NCs.…”

“…We believe that 1D CSs may be applied as nanodevices. However, at present, few experiments on the conductivity of 1D CSs have been reported [ 146 , 152 ]. In the future, it is expected that the conductivity of 1D CSs will be measured as a basic physical property.…”

“…Zhang et al also very recently reported the formation of 1D CS consisting of the (AuAg) 34 (A-Adm) 20 alloy NCs (A-Adm = 1-ethynyladamantane; Scheme 1 (9)) [ 146 ]. For (AuAg) 34 (A-Adm) 20 alloy NCs, either monomeric NC or 1D CSs were formed depending on the solvent.…”

“…( D , E ) Electrical transport properties of the cluster polymer crystals; ( D ) structure of the polymer crystal FET; ( E ) I – V plot of the polymer crystal along a -axis and c -axis, respectively, with the range of corresponding conductivity values shown in the inset. Reproduced with permission from Reference [ 146 ]. Copyright 2020 Springer-Nature.…”