Open AccessNurturing Plasmonic Properties of Nanocomposite Thin Films: The Importance of Optimum Oblate Shape
Author(s) -
Ranjit Laha
Publication year - 2021
Publication title -
journal of materials and applications
Language(s) - English
Resource type - Journals
eISSN - 2051-7750
pISSN - 2051-7742
DOI - 10.32732/jma.2021.10.2.73
Subject(s) - nanocomposite , materials science , plasmon , dielectric , surface plasmon resonance , quadratic equation , volume fraction , nanoparticle , wavelength , resonance (particle physics) , extinction (optical mineralogy) , nanotechnology , optoelectronics , composite material , optics , physics , mathematics , geometry , atomic physics
Metal nanoparticles (MNPs) embedded dielectric thin films are very crucial for many optoelectronic applications. This report investigates various ways of tuning the plasmonic properties of such nanocomposite thin films. For this, the well-known plasmon resonance condition was first generalized to include the shape and volume fraction of MNPs. This was followed by deriving an empirical formula for the resonance position (λR) which was worked out to be the positive root of a quadratic equation. The coefficients of the deduced quadratic relation involve the parameters obtained from the empirical fit to some of the experimental dielectric functions of MNPs available in literature. The derived working formula enables research community to tune the LSPR of nanocomposites in the whole range of visible wavelengths. The derived formula also concluded that with known lower volume fractions, shape of MNPs affects λR the most, compared to the other parameters. The derived formula was validated by calculating the full extinction spectra. It was shown for the first time that there exists an optimum value of oblate shape to give maximum resonance for a given nanocomposite.