Nitrides as Alternative Materials for Plasmonics

Abstract

Noble metal-based nanostructures exhibit plasmonic resonance in the visible region. Search is for plasmonic materials active in other regions of electromagnetic spectrum. Alternative materials such as nitrides, carbides and semiconductors play an important role in nanophotonics as optical properties in these materials can be tuned to study plasmonic response. Also alternative materials to noble metals should have multiple properties like low optical losses, thermal and chemical stability, cost effective, easy to fabricate and also must have CMOS compatibility. Alternative materials such as transition metal nitrides fulfil these conditions up to a certain extent. In this work, optical properties of nitrides as alternative materials to noble metals are studied theoretically and compared with noble metals such as Au and Ag. Nitrides are having real part of permittivity less negative as compared to noble metals and both real and imaginary parts are extending up to infrared region. It is shown by comparison that nitrides such as TiN and ZrN are having absorption spectrum extending up to infrared region thereby making them suitable materials in the construction of devices. TiN and ZrN nanostructures show their potential for plasmonic performance in a wider spectral range than those made of Au or Ag and can act as next-generation materials for refractory plasmonics.