Palladium Germanides for Mid- and Long-Wave Infrared Plasmonics

Abstract

Palladium germanide thin films were investigated for infrared plasmonic applications. Palladium thin films were deposited onto amorphous germanium thin films and subsequently annealed at a range of temperatures. X-ray diffraction was used to identify stoichiometry, and Scanning Electron Micrographs, along with Energy Dispersive Spectroscopy (EDS) was used to characterize composition and film quality. Resistivity was also measured for analysis. Complex permittivity spectra were measured from 0.3 to 15 μm using IR ellipsometry. From this, surface plasmon polariton (SPP) characteristics such as propagation length and mode confinement were calculated and used to determine appropriate spectral windows for plasmonic applications with respect to film characteristics. Films were evaluated for use with on-chip plasmonic components.