Design Of Silver Nanoparticles Research Articles

Optimized design of silver nanoparticles for broadband and high efficiency light trapping in thin film solar cells

This paper reports a high-efficiency approach to improve the photoelectric-conversion efficiency of thin-film solar cells by plasmonic scattering and local near-field amplification of silver nanoparticles. We employ a three-dimensional (3D) electromagnetic model and use the finite-difference time-domain (FDTD) and rigorously coupled-wave analysis methods to investigate the interaction of light with such a metallic particle. The numerical results show that the absorption and scattering spectra depend upon the properties of the embedded particles and the refractive index of the surrounding material. Strong redshifts and high-order modes are observed in the response spectrum with the increase of the particle size and the refractive index of the surrounding material. With an optimized design having [Formula: see text], [Formula: see text], and [Formula: see text] nm, the performance of cell device is improved over a broad spectral range. Moreover, some of the absorption, in the resonance region, is beyond the Yablonovitch limit. The corresponding light-generated photocurrent is increased from 14.2 mA/cm2 to 18.3 mA/cm2, with a 28.9% enhancement compared with conventional cells with antireflective coatings (ARCs).

Design of silver nanoparticles with graphene coatings layers used for LSPR biosensor applications

A new hybrid graphene nanoplasmonic structure, using silver nanoparticles (AgNPs) coated with a graphene film and deposited on a substrate is proposed in this paper. The aim is to obtain a plasmonic response with high sensitivity for plasmonic biosensors. We show, through the calculation of absorption spectra, that the localized surface plasmon resonance (LSPR) obtained in the SiOx/AgNPs/Graphene nanostructure is very sensitive to variations in the thickness of the graphene and those of the refractive index of the detection medium. The study reveals a shift in plasmon resonance peaks resulting from the coupling between the AgNPs networks and the covering graphene layer. We obtained the red-shift of LSPR modes from 412 nm to 548 nm when the thickness of the graphene layer increases from 0.34 nm to 9 nm. We have shown that the increase in graphene thickness significantly affects the sensitivity of the device under study. An optimal sensitivity value is obtained for a graphene thickness of 9 nm, with a 304.60% gain in sensitivity value compared to the structure without graphene. These properties should enhance these nano-device and make them a preferred choice for biosensors applications, over other current biosensors.

The Role of Calix[n]arenes and Pillar[n]arenes in the Design of Silver Nanoparticles: Self-Assembly and Application.

Silver nanoparticles (AgNPs) are an attractive alternative to plasmonic gold nanoparticles. The relative cheapness and redox stability determine the growing interest of researchers in obtaining selective plasmonic and electrochemical (bio)sensors based on silver nanoparticles. The controlled synthesis of metal nanoparticles of a defined morphology is a nontrivial task, important for such fields as biochemistry, catalysis, biosensors and microelectronics. Cyclophanes are well known for their great receptor properties and are of particular interest in the creation of metal nanoparticles due to a variety of cyclophane 3D structures and unique redox abilities. Silver ion-based supramolecular assemblies are attractive due to the possibility of reduction by “soft” reducing agents as well as being accessible precursors for silver nanoparticles of predefined morphology, which are promising for implementation in plasmonic sensors. For this purpose, the chemistry of cyclophanes offers a whole arsenal of approaches: exocyclic ion coordination, association, stabilization of the growth centers of metal nanoparticles, as well as in reduction of silver ions. Thus, this review presents the recent advances in the synthesis and stabilization of Ag (0) nanoparticles based on self-assembly of associates with Ag (I) ions with the participation of bulk platforms of cyclophanes (resorcin[4]arenes, (thia)calix[n]arenes, pillar[n]arenes).

Studies on Curcumin Loaded Poly(N-isopropylacrylamide) Silver Nanocomposite Hydrogels for Antibacterial and Drug Releasing Applications

Design of silver nanoparticles containing poly(N-isopropylarclamide) (PNIPAAm) hydrogels were prepared by free-radical polymerization of N-isopropylarclamide as an environmentally sensitive monomer and MBA as a crosslinker in an aqueous medium. The embedded silver nanocomposite hydrogels (AgNCH) structure were characterized by, UV-Vis, FTIR, DLS, TEM and X-ray analysis. Curcumin loading and release characteristics were performed for PNIPAAm hydrogel, silver ions loaded hydrogels as well as silver nanocomposite hydrogels. These curcumin loaded silver nanocomposite hydrogels exhibit excellent antibacterial action on Escherichia coli (E. coli). Therefore, the present study clearly provides novel antimicrobial hydrogels which are potentially useful in biomedical applications.