Aluminum Nano Stars with Localized Surface Plasmon Resonance and Field Enhancement

Abstract

Aim: The Finite Difference Time Domain approach has been used to assess the localised surface plasmon resonance and field enhancement for Al nanostars. The structure's potential as a refractive index sensor has been demonstrated. Background: Research on plasmonics has been possible in a variety of domains, including sensors, SERS, solar cells, and others, due to a tenability in the plasmon wavelength caused by a simple change in shape, size, or external environment. The growth of plasmonics has been greatly aided by the creation of novel ways for creating metallic nanostructures and a large deal of work on the creation of numerical algorithms to cope with arbitrarily shaped metallic nanostructures. The LSPR and field enhancement of an Al nano-star were the main topics of this paper. A larger RIS factor is obtained after adjusting the refractive index sensitivity parameter, making it appropriate for refractive index-based sensor nanostructures. Objective: This study's primary goal is to provide a comparative analysis of the refractive index sensitivity factor for Al nanostars dependent on their size and number of arms. Methods: Al nano star's LSPR and field enhancement have been assessed using the Finite Difference Time Domain (FDTD). Results: By altering the size and number of arms of the nano star, the tenability of the plasmonic peak has been assessed, and it has been found that the peak is sensitive to the ambient dielectric constant. A study has been done on the refractive index sensitivity parameter. A higher sensitivity of about 370 nm/RIU, which is significantly higher than that of other metallic Nanostar (NS), is seen after adjusting the size and number of arms. A wide range of applications is covered by the Al NS field enhancement pattern, which exhibits stronger enhancement with no aggregation at the plasmon peak. Conclusion: For LSPR sensing applications, the impact of modifying the environmental dielectric constant is examined. By changing the size and quantity of the Al NS's arms, we were able to compare the refractive index sensitivity parameter. The bigger size NS exhibits more peaks due to the contribution of the multipole; however, after tuning a number of parameters, better sensitivity in comparison to Au and Ag nanostar has been attained. Al NS can therefore be a promising sensing material for refractive index sensing employing LSPR properties.