Nanoparticle Arrays

Abstract

Arrays of metal nanoparticles in an organic matrix have attracted a lot of interest due to their diverse electronic and optoelectronic properties. By varying parameters such as the nanoparticle material, the matrix material, the nanoparticle size, and the interparticle distance, the electronic behavior of the nanoparticle array can be substantially tuned and controlled. For strong tunnel coupling between adjacent nanoparticles, the assembly exhibits conductance properties similar to the bulk properties of the nanoparticle material. When the coupling between the nanoparticles is reduced, a metal insulator transition is observed in the overall assembly. Recent work demonstrates that nanoparticle arrays can be further utilized to incorporate single molecules, such that the nanoparticles act as electronic contacts to the molecules. Furthermore, via the excitation of the surface plasmon polaritons, the nanoparticles can be optically excited and electronically read out.

Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes

“…The most likely explanation for the small current increase due to the illumination of Ru(MPTP) 2 -AuNP devices is that the AuNPs act as optical antennae, as described in [37][38][39][40][41][42]. This is supported by the increase of current due to irradiation with light of wavelengths larger than 520 nm corresponding to the surface plasmon band (see Supporting Information File 1, Figure S13), while no current increase is recorded at the wavelength corresponding to the MLCT band.…”

“…We can completely rule out a bolometric conductance enhancement like discussed for large nanoparticle arrays. We irradiate our device with 90 nW/cm 2 only to exclude this influence, in contrast to otherwise used light intensities in the kW/cm 2 range, which are described to cause an increase in temperature of approximately 0.55 K under certain conditions [37]. Furthermore, it is unlikely that the conductance switching in our Ru(MPTP) 2 -AuNP devices corresponds to photoconductance as discussed for AuNP arrays consisting of AuNPs coated with monolayers of organic molecules [38].…”

Applications of surface‐enhanced Raman spectroscopy in environmental detection

“…Nanoparticle arrays are sometimes used as a technique of arranging nanomaterials into a well‐ordered system that exhibits desirable properties. Their properties can be controlled by engineering the nanoparticle shape, size and distance from other particles 52 . The small gaps between the nanoparticles have enhanced electromagnetic fields, leading to the generation of SERS hot spots across a three‐dimensional (3D) structure 53 .…”