%0 Journal Article
%T Searching for Alternative Plasmonic Materials for Specific Applications
%A Amit Bansal
%A S. S. Verma
%J Indian Journal of Materials Science
%D 2014
%R 10.1155/2014/897125
%X The localized surface plasmon resonance (LSPR) based optical properties such as light scattering, absorption, and extinction efficiencies of multimetallic and metal-semiconductor nanostructures will be studied. The effect of size, surrounding medium, interaction between the particles, composition of the particles, and substrate on LSPR peak position, its line width, and maxima of cross-sections will also be discussed to optimize the selected systems for various applications like plasmonic sensors and biomedical applications and to enhance the efficiency of solar cells. Therefore, by varying all these factors, the LSPR peak of multimetallic and metal-semiconductor nanostructures can be tuned over the entire UV-visible to infrared (IR) region of the electromagnetic spectrum. Moreover the optical properties of underlying semiconductor materials can be enhanced by combining the semiconductor with noble metal nanoparticles. 1. Introduction Plasmonics, which is the property of metal nanostructures due to surface plasmons, has become one of the most expanding fields in nanoscience. The goal of plasmonics is to control, tune, and manipulate light on the nanometer scale using the properties of collective electron excitations, known as surface plasmons. In plasmonic nanoparticles, the localized surface plasmon resonance (LSPR) supported at the optical frequencies where resonance occurs due to the collective excitation of conduction electrons, in response to the electric field component of the irradiated electromagnetic (EM) waves [1]. This is due to the fact that while oscillating EM wave incident on the conduction electrons of the metal nanoparticles, which are confined to the small volume, the conduction band electrons starts oscillate collectively with respect to the positive framework that leads to the charge separation at the nanoparticle surface and results in the production of restoring force [2] as shown in Figure 1. Figure 1: Schematics for plasmon oscillations. The main need for LSPR is a large negative real part and a small imaginary part of the dielectric constant of the material. There are a large number of metals, that is, Li, Na, Al, Pb, Cd, In, and Ga, which satisfies this criterion and their plasmon resonances lie in the UV-Vis to infrared (IR) region of the EM spectrum. Most of these metals are rapidly oxidized and become unstable, and hence it is difficult to work with them [3], but the metals such as Au, Ag, and Cu attracted much attention because they are nobler in nature and able to form stable colloids with surrounding environment.
%U http://www.hindawi.com/journals/ijms/2014/897125/