Damage Analysis in Ag Nanoparticle Interconnect Line Under High-Density Electric Current

Printed electronics (PEs) have attracted attention for the fabrication of microscale electronic circuits. PEs use conductive inks which include metal nanoparticles. The conductive ink can be printed on flexible substrates for wearable devices using ink-jet printers and roll-to-roll methods. With the scaling down of electric devices, the current density and Joule heating in the device lines increase, and electromigration (EM) damage becomes significant. EM is a transportation phenomenon of metallic atoms caused by the electron wind under high-density current. Reducing the EM damage is extremely important to enhance the device reliability. With the progress in miniaturization of the metal nanoparticle ink lines, EM problem needs to be solved for ensuring the reliability of these lines. We know that the formation of aggregates and cathode damages occur due to a current loading. The diffusion path of atoms due to the EM has not been identified under the high-density current loading. In this study, a high-density electric current loading was applied to an Ag nanoparticle line. The line specimens were prepared using a lift-off method. After the current loading tests, observations were conducted using a laser microscope and scanning electron microscope. A local decrease in the line thickness and scale-shaped slit-like voids were observed due to the high-density current loading. Moreover, the microstructure of the line was modified by enlarging the Ag grain. From the results, we identified that a dominant diffusion occurred at the Ag grain boundary due to the EM.

Synthesis and Near-Field Enhancement of Composite Nanoarrays Based on Electrodeposition and in Situ Reaction

Since the morphology and element composition of metal nanostructures strongly affect the surface plasma oscillation characteristics, it has been widely concerned in surface enhanced Raman scattering (SERS). Herein, we proposed a novel route to fabricate composite Au/Ag nanoparticle arrays with synergistic effect for electromagnetic enhancement. Ag nanoparticles were electrodeposited onto a home-made template with highly ordered bowl-like pits. After a novel method of “confined annealing”, we further achieved well-regulated spherical Ag NP arrays, and the composite Au/Ag nanoparticle arrays were finally obtained via in situ replacement. The fabricated composite nanostructures showed stable and sensitive surface enhanced Raman scattering (SERS) performance mainly due to the synergistic effect and abundant “hot spots”, with the enhancement factor (EF) of [Formula: see text] for crystal violet (CV) molecules. In addition, this simple and effective preparation process greatly improved the uniformity of three-dimensional nanostructures, providing a new idea for further improving the stability of SERS signals.

Chitosan-Ag nanoparticle antifungal activity against Fusarium sp., causal agent of wilt disease on chili

Chitosan is a polysaccharides compound derived from nature and has an amine group and a hydroxyl group that gives it unique physicochemical properties, which are polychationic and chelating agent. This shows that chitosan can be used as a stabilizer and reducer of Ag nanoparticles. Unlike other studies, chitosan that was used in this study was derived from Black Soldier Fly exuviae which has been through demineralization, deproteination, depigmentation, and deacetylation processes. This study aims to obtain an alternative environmentally friendly fungicide with Ag-chitosan nanoparticle formulation which has antifungal activity against Fusarium sp. that causes wilt disease in chili plants. We analysed particle size, functional group by FTIR, and antifungal test against Fusarium sp. on 1000, 750, 500, 250, and 100 ppm of chitosan-Ag nanoparticle. The chitosan-Ag nanoparticles have a particle size of 188.4 nm with a polydispersity index of 0.344. FTIR analysis showed that Ag+ ions are successfully grafted into the chitosan matrix. All the chitosan-Ag nanoparticle concentration tested showed significant results with negative and positive control, except the concentration of 100 ppm which is not significantly differ from negative control. The antifungal test showed a concentration of 750 ppm chitosan-Ag nanoparticles had a growth inhibition of 72.17%.