Lossless Phase Change Materials for Adjustable Tamm Plasmon Polaritons in the Near‐Infrared

Abstract Incorporation of phase‐change materials (PCM) into nanophotonic structures is a straightforward method for making them tunable. The binary semiconducting chalcogenide antimony trisulfide (Sb₂S₃) is a suitable PCM for nanophotonic applications in the near‐infrared (NIR) owing to its high refractive index, low optical losses, and wide bandgap. Therefore, in this study, Sb₂S₃ Tamm plasmon polaritons (TPPs) are fabricated with a focus on their widespread use in nanophotonic applications. For this, a gold film and Sb₂S₃ are deposited on the distributed Bragg reflector through e‐beam evaporation. TPPs are excited at the interface between the distributed Bragg reflector (DBR) and the metal layer. The refractive index, extinction coefficient, and high‐Q reflectance spectra of the developed Sb₂S₃ are measured and analyzed. The Sb₂S₃ TPPs exhibit a resonance shift of 45 nm caused by the phase change of Sb₂S₃ from amorphous to crystalline. In addition, the angle‐dependent resonance shifts of 85, 76, and 63 nm are achieved by unpolarized, transverse magnetic (TM), and transverse electric (TE) modes near NIR light, respectively. The developed Sb₂S₃ TPP can be applied in various nanophotonics applications, including optical memory, optical data storage, and LiDAR receiver systems.