Examining the Performance of Refractory Conductive Ceramics as Plasmonic Materials: A Theoretical Approach

Abstract

The main aim of this study is to scrutinize promising plasmonic materials by\nunderstanding their electronic structure and correlating them to the optical\nproperties of selected refractory materials. For this purpose, the electronic\nand optical properties of the conductive ceramics TiC, ZrC, HfC, TaC, WC, TiN,\nZrN, HfN, TaN, and WN are studied systematically by means of first-principles\ndensity functional theory. A full ab initio procedure to calculate plasma\nfrequency from the electronic band structure is discussed. The dielectric\nfunctions are calculated by including electronic interband and intraband\ntransitions. Our calculations confirm that transition metal nitrides, such as\nTiN, ZrN, and HfN, are the strongest candidates, exhibiting performance\ncomparable to that of conventional noble metals in the visible to the\nnear-infrared regions. On the other hand, carbides are not suitable for\nplasmonic applications because they show very large losses in the same regions.\nFrom our calculated dielectric functions, the scattering and absorption\nefficiencies of nanoparticles made of these refractory materials are evaluated.\nIt is revealed that TiN and TaC are the best candidate materials for\napplications in photothermal energy conversion over a broad spectral region.\nFurthermore, quality factors for localized surface plasmon resonance and\nsurface plasmon polaritons are calculated to compare quantitative performances,\nand ZrN and HfN are found to be comparable to conventional plasmonic metals\nsuch as silver and gold\n