Effect of edge smoothening on the extinction spectra of metal nanoparticles

Abstract

To calculate the extinction spectrum of a metal nanoparticle, it is common to use a regular shape which is close to the experimental one. We show that, to model a real metal particle, it is essential to remove sharp corners and tips and smoothen the bounding surface. An efficient and simple method to smoothen the tips and corners of the model shape of the particle is presented. The extinction calculated using smoothed particles predicts more accurately the extinction spectrum of as grown particles as well as the changes in the extinction spectrum during melting and reshaping of the particle.

Modeling and analysis of post plasmonic effects in optically excited metal nanosystems

“…The power absorbed by the particle comprises mainly resistive heating of the particle during the laser irradiation [110], which is directly proportional to the absorption cross section (α abs ) by P abs = I g α abs [26], where I g is the light intensity. Similar to the observations from previous studies [139][140][141] our calculations show a reduction in absorption with smoothening or increasing ROC. Figure 3.3 shows the calculated absorption profile of bare AgNPr and AgNPr@SiO 2 respectively.…”

“…Analytical models and solutions of scattering and absorption of electromagnetic (EM) waves can be estimated only for simple and symmetric particles like spheres [139]. For nanoparticles like rods and prisms, numerical techniques should be used.…”

“…For nanoparticles like rods and prisms, numerical techniques should be used. In such studies with nanoparticle models using ideal sharp edges in numerical calculations were proven to produce erroneous results against nanoparticle models with corner and/or edge smoothening [139][140][141]. Even though only the finite radius of curvature (ROC) at the three corners was considered in few of these studies [140,141], the melting ice model [139] which considered smoothening of both the corners as well as edges was close to the real case.…”

“…In such studies with nanoparticle models using ideal sharp edges in numerical calculations were proven to produce erroneous results against nanoparticle models with corner and/or edge smoothening [139][140][141]. Even though only the finite radius of curvature (ROC) at the three corners was considered in few of these studies [140,141], the melting ice model [139] which considered smoothening of both the corners as well as edges was close to the real case. So, we initially performed a simulation analysis of corner and edge smoothening individually on the AgNPr@SiO 2 to relate the significance of edge A 10 nm thick silica coated silver nanoplate (AgNPr@SiO 2 ) of 110 nm side (10 nm thickness) and using different ROC combinations of corners and edges were considered for our study.…”

Role of Auger Recombination in Plasmon Controlled Photoluminescence Kinetics in Metal-Semiconductor Hybrid Nanostructures

“…The extinction spectra of the Ag PT colloid shows an in-plane dipole LSPR peak around 2.05 eV and an out-of-plane quadruple peak at 3.69 eV (Fig. 1(a)) 34 .…”