Plasmonics is a research area merging the fields of optics and
nanoelectronics by confining light with relatively large free-space wavelength
to the nanometer scale - thereby enabling a family of novel devices. Current
plasmonic devices at telecommunication and optical frequencies face significant
challenges due to losses encountered in the constituent plasmonic materials.
These large losses seriously limit the practicality of these metals for many
novel applications. This paper provides an overview of alternative plasmonic
materials along with motivation for each material choice and important aspects
of fabrication. A comparative study of various materials including metals,
metal alloys and heavily doped semiconductors is presented. The performance of
each material is evaluated based on quality factors defined for each class of
plasmonic devices. Most importantly, this paper outlines an approach for
realizing optimal plasmonic material properties for specific frequencies and
applications, thereby providing a reference for those searching for better
plasmonic materials.Comment: 27 pages, 6 figures, 2 table