Altering the dewetting characteristics of ultrathin gold and silver films using a sacrificial antimony layer

Abstract

Solid state dewetting of ultrathin films is the most straightforward means of fabricating substrate-supported noble metal nanostructures. This assembly process is, however, quite inflexible, yielding either densely packed smaller structures or widely spaced larger structures. Here, we demonstrate the utility of introducing a sacrificial antimony layer between the substrate and noble metal overlayer. We observe an agglomeration process which is radically altered by the concurrent sublimation of antimony. In stark contrast with conventional dewetting, where the thickness of the deposited metal film determines the characteristic length scales of the assembly process, it is the thickness of the sacrificial antimony layer which dictates both the nanoparticle size and interparticle spacing. The result is a far more flexible self-assembly process where the nanoparticle size and areal density can be varied widely. Demonstrations show nanoparticle areal densities which are varied over four orders of magnitude assembled from the identical gold layer thickness, where the accompanying changes to nanostructure size see a systematic shift in the wavelength of the localized surface plasmon resonance. As a pliable self-assembly process, it offers the opportunity to tailor the properties of an ensemble of nanostructures to meet the needs of specific applications.

RETRACTED: Investigation of plasmonic studies on morphology of deposited silver thin films having different thicknesses by soft computing methodologies—A comparative study

“…Some distinct holes appear on the surface at this temperature (Fig. 2), indicating partial embedding of Ag particles in the substrate during high temperature annealing as reported in past studies [4,10]. For this work, thermal annealing is carried out at 250 1C since smallest diameters corresponding to 5 nm can be obtained, and hence confirm this as the most appropriate temperature to transform Ag thin films to Ag particles.…”

“…Thin films go through an annealing process at an appropriate temperature in order for dewetting to take place. This annealing process will drive the film toward an equilibrium state, whereupon it agglomerates into metal nanostructures at temperatures well below the melting point of the metal [10,11]. Electron beam lithography is the most popular, albeit costly, technique of fabricating arrays of MNPs in preferred sizes, shapes and inter-particle distances [12,13].…”

Photocatalytic Enhancements to the Reduction of 4-Nitrophenol by Resonantly Excited Triangular Gold–Copper Nanostructures

“…The substrate-immobilized Au templates were formed through the solid-state dewetting of 12 nm thick sputter deposited films using procedures described in detail elsewhere. 41 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Catalysis. All catalysis measurements were performed using a 2 mL aqueous solution of 70 µM 4-NP and 7 mM NaBH 4 prepared using DI water.…”

“…The Au templates used in this assembly process (Figure 1a) are formed through the solid state dewetting 40 of 12 nm thick sputter deposited Au films onto (0001)-oriented sapphire substrates. 41 The substrate and a Cu foil, both identical in size, are then placed into slots cut into an alumina crucible which maintains a separation distance of 0.5 mm ( Figure 1b). The loaded crucible is then inserted into a tube furnace with flowing Ar and heated to a temperature of 885 °C for time intervals lasting up to 24 hr.…”

The process of solid-state dewetting of Au thin films studied by in situ scanning transmission electron microscopy

“…Approaches include pre-patterning the substrate [10][11][12][13][14][15] or the thin film [16][17][18][19] and the introduction of a sacrificial layer [20,21]. Applications of the produced particle arrays are envisaged to range from templates for the growth of nanostructures [22,11,23,24], magnetic storage arrays [25,26], optical sensors [27,28] and plasmonic systems [29,30], over photocatalytic reactors [31] to plasmon-enhanced back reflectors in solar cells [32,33].…”