Monitoring and modeling the deposition of metal nanoparticles on surfaces by impedance

Abstract

The study of metallic nanoparticles (NPs) on surfaces and their properties has become a common subject for a variety of areas. Notably, to exploit the unique intrinsic features of deposited NPs in macroscopic devices, samples with low coverage are required. The electrical characterization techniques has, however, so far been limited mostly to systems near or beyond the percolation limit, when the nanostructure's resistive behavior is dominant. Here we describe the impedance response of interdigitated electrodes (IDE) during Ag NP deposition, from the very beginning up to the percolation limit. Our experiments present two regimes: up to ∼20% of coverage the capacitance grows linearly with the deposition, increasing abruptly afterward. To understand the experimental data, we propose a model in which the capacitance response is attributed to isolated and agglomerated NPs. Initially, isolated NPs contribute to the ca-

Controlled Incorporation of Silver Nanoparticles into Layer-by-Layer Polymer Films for Reusable Electronic Tongues

“…Although PAH and PSS are polyelectrolytes, the electrostatic interactions during multilayer assembly lead to electrical dipoles, which confer an insulating behavior for the PAH/ PSS LbL architecture. 31 2.2. Nanoparticle Production and Deposition.…”

“…The IDE electrical response was monitored during the silver nanoparticle deposition in situ using a homemade impedance meter, described in detail elsewhere. 33 Briefly, a sinusoidal voltage of 1 V amplitude and 1 kHz is applied to one comb of the IDE digits. The current from the pick-up electrode is amplified using an operational amplifier in a differential configuration.…”

“…30 The concentration of nanoparticles was calculated according to the p e r c e n t a g e , using a typical deposition current of 330 pA, and the parameters described elsewhere. 33 2.3. Impedance Spectroscopy.…”

“…We deposited silver nanoparticles of an average diameter of 3 nm, with a typical current of 300–500 pA measured on the current detector with a 75 mm 2 area. The IDE electrical response was monitored during the silver nanoparticle deposition in situ using a homemade impedance meter, described in detail elsewhere . Briefly, a sinusoidal voltage of 1 V amplitude and 1 kHz is applied to one comb of the IDE digits.…”

“…We interpreted the impedance measurements using an equivalent circuit coupling parallel capacitive and conductive components . The concentration of nanoparticles was calculated according to the percentage of covered area , using a typical deposition current of 330 pA, and the parameters described elsewhere …”