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

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.

Effect of Postdeposition Heat Treatment on the Nanoplasmonic Behavior of Glancing Angle‐Deposited Silver Nanostructures

“…The event is similar to the solid‐state dewetting (SSD) phenomenon, where smaller nanoparticles are produced from a continuous thin film upon appropriate annealing. [ 12 ] The effect is also visible in the corresponding particle size histogram. The cross‐sectional FESEM data of the GLAD Ag thin films annealed at different temperatures were investigated to study the effect of annealing temperature on the physical thickness of the films (i.e., the vertical size of the Ag nanoparticles).…”

Fabrication of Platinum Nanoparticles with Different Morphologies by Thermal Dewetting in the Presence of Residual Oxygen and Their Optical Properties

“…Kunwar et al observed the change in the Pt NP shape from irregular to semispherical to hexagonal when the temperature was increased from 700 to 900 °C in their work on using an In sacrificial layer to enhance solid-state dewetting of Pt films. Similarly, Ag NPs evolved from elongated shape at low temperatures to oval, and eventually to spherical shape as the temperature and annealing time increased in the solid-state dewetting of thin Ag films in air …”

“…This change from a nontextured structure to a textured one due to thermal dewetting has also been observed in Ag films. 44 Pt has a facecentered cubic unit cell. The lattice constant extracted from the Pt (111) peak for the three Pt NPs described above was 3.915 Å.…”

Microreactor-based micro/nanomaterials: fabrication, advances, and outlook

“…Additionally, Ag nanoparticles are mainly used in photographic reactions, catalysis and chemical analysis. [133][134][135] Nightingale et al 136 from Imperial College London in the UK proposed a general-purpose capillary-based droplet reactor with a main capillary diameter of 0.82 mm and a distance of 20 cm from the droplet formation point to the capillary outlet. Using this microreactor, silver nitrate (AgNO 3 ) is reduced with sodium borohydride (NaBH 4 ) at room temperature, and Ag nanoparticles with an average particle size of 12 AE 4 nm are synthesized.…”