Silver Nanoparticle Arrays onto Glass Substrates Obtained by Solid-State Thermal Dewetting: A Morphological, Structural and Surface Chemical Study.

Juan Agustín Badán,Enrique A Dalchiele,Rodrigo Henríquez,Daniel Ariosa,José Ramón Ramos-Barrado,Elena Navarrete-Astorga,Francisco Martín Jiménez

doi:10.3390/nano12040617

Abstract

Silver nanoparticles (NPs) on glass substrates were obtained by a solid-state thermal dewetting (SSD) process using vacuum-evaporated-silver precursor layers. An exhaustive investigation of the morphological, structural, and surface chemistry properties by systematically controlling the precursor film thickness, annealing temperature, and time was conducted. Thin silver films with thicknesses of 40 and 80 nm were deposited and annealed in air by applying a combined heat-up+constant temperature–time program. Temperatures from 300 to 500 °C and times from 0 to 50 min were assayed. SSD promoted the morphological modification of the films, leading to the Ag NPs having a discrete structure. The size, shape, surface density, and inter-nanoparticle distance of the nanoparticles depended on the initial film thickness, annealing temperature, and time, exhibiting a cubic silver structure with a (111) preferred crystallographic orientation. The prepared NPs were found to be highly enriched in the Ag{111}/Ag{110}/Ag{100} equilibrium facets. SSD not only promotes NP formation but also promotes the partial oxidation from Ag to AgO at the surface level. AgO was detected on the surface around the nanoparticles synthesized at 500 °C. Overall, a broad framework has been established that connects process factors to distinguish resultant Ag NP features in order to develop unique silver nanoparticles for specific applications.

Highlights

Noble metallic nanoparticles (Au, Pt, Ag) (NPs) have attracted a great deal of attention due to their unique physical features and interesting electrochemical and mechanical properties [1,2,3,4,5,6]
The development of single-molecule analytical systems has received a lot of interest in recent years; as a result, innovative sensing technologies based on localized surface plasmons in metallic nanoparticles have received a lot of attention [9,16]
Silver nanoparticle (NP) arrays were formed on the glass surface through the solidstate dewetting (SSD) process, which consists of two steps: (i) a precursor silver layer is deposited onto glass substrates, and (ii) these samples are submitted to an annealing treatment to trigger the actual solid-state dewetting process

Summary

Introduction

Noble metallic nanoparticles (Au, Pt, Ag) (NPs) have attracted a great deal of attention due to their unique physical features and interesting electrochemical and mechanical properties [1,2,3,4,5,6]. Noble metal nanoparticles have been rapidly produced for applications such as surface-enhanced Raman scattering (SERS) [14,15]. Due to their unique optical properties, the noble metallic nanoparticles detailed and discussed above have been intensively employed in a broad range of applications in the biomedical (bioimaging, biosensing, nanosurgery, drug delivery, photothermal therapy), energy, catalysis, and information technology (data storage) fields [2,7]. The development of single-molecule analytical systems has received a lot of interest in recent years; as a result, innovative sensing technologies based on localized surface plasmons in metallic nanoparticles have received a lot of attention (i.e., single-molecule sensing by fluorescence enhancement and plasmon shifts) [9,16]

Methods

Results

Conclusion