AlN-based hybrid thin films with self-assembled plasmonic Au and Ag nanoinclusions

Abstract

Aluminum nitride (AlN)-based two-phase nanocomposite thin films with plasmonic Au and Ag nanoinclusions have been demonstrated using a one-step thin film growth method. Such AlN-based nanocomposites, while maintaining their wide bandgap semiconductor behavior, present tunable optical properties such as bandgap, plasmonic resonance, and complex dielectric function. Depending on the growth atmosphere, the metallic nanoinclusions self-organized into different geometries, such as nano-dendrites, nano-disks, and nanoparticles, providing enhanced optical anisotropy in-plane and out-of-plane. The infrared transmission measurements demonstrate the signature peaks of AlN as well as a broad transmission window attributed to the plasmonic nanoinclusions. This unique AlN-metal hybrid thin film platform provides a route to modulate the optical response of wide bandgap III-V nitride semiconductors towards infrared sensing or all optical based integrated circuits.