Stress-induced phase transformation and optical coupling of silver nanoparticle superlattices into mechanically stable nanowires

Abstract

One-dimensional silver materials display unique optical and electrical properties with promise as functional blocks for a new generation of nanoelectronics. To date, synthetic approaches and property engineering of silver nanowires have primarily focused on chemical methods. Here we report a simple physical method of metal nanowire synthesis, based on stressinduced phase transformation and sintering of spherical Ag nanoparticle superlattices. Two phase transformations of nanoparticles under stress have been observed at distinct length scales. First, the lattice dimensions of silver nanoparticle superlattices may be reversibly manipulated between 0-8 GPa compressive stresses to enable systematic and reversible changes in mesoscale optical coupling between silver nanoparticles. Second, stresses greater than 8 GPa induced an atomic lattice phase transformation, which induced sintering of silver nanoparticles into micron-length scale nanowires. The nanowire synthesis mechanism displays a dependence on both nanoparticle crystal surface orientation and presence of particular grain boundaries to enable nanoparticle consolidation into nanowires.

Pressure-induced emission of cesium lead halide perovskite nanocrystals

“…The cesium lead halide perovskite of Cs 4 PbBr 6 is a typical zero-dimensional (0D) inorganic MHP, in which the octahedra are completely isolated by cation bridges and charge carriers are localized within the ordered metal halide component 7–10 . The electronic structure and optical properties of these materials are expected to show a significant dependence on pressure 11–16 . In view of this, our group has explored their pressure dependence and found, for example, that the band gap alignment of CsPbBr 3 NCs can be successfully fine-tuned via pressure 17 .…”

Nanomaterials under stress: A new opportunity for nanomaterials synthesis and engineering

“…51 We observed tunable SPR of Ag NPs and nanowires depending upon the external compression and release of pressure ( Figure 8 ). 39 At ambient pressure, the UV-vis spectrum shows a single peak at 518 nm corresponding to the Ag NP assemblies. Signifi cant redshifts ranging from 518 nm to 548 nm were observed upon increasing pressure.…”

“…39 Silver NPs were synthesized through a thermal decomposition method using myristic acid as the surface ligand. The Ag NPs were fairly monodisperse with an average diameter of 5.5 nm and a narrow size distribution.…”

Silver nanoparticles-containing dual-function hydrogels based on a guar gum-sodium borohydride system

“…Metal nanoparticles exhibit size- and shape-dependent properties that endow them with various promising applications in many areas including catalysis, nanoelectronics, nanometal inks and antibiotics13141516. Among these metal nanoparticles, silver nanoparticles (AgNPs) have attracted much attention due to their broad spectrum of antibacterial activity and they are being incrementally applied in medical areas like wound dressings17.…”