The realization of electrically tunable
plasmonic resonances in
the ultraviolet (UV) to visible spectral band is particularly important
for active nanophotonic device applications. However, the plasmonic
resonances in the UV to visible wavelength range cannot be tuned due
to the lack of tunable plasmonic materials. Here, we experimentally
demonstrate tunable plasmonic resonances at visible wavelengths using
a chalcogenide semiconductor alloy such as antimony telluride (Sb2Te3), by switching the structural phase of Sb2Te3 from amorphous to crystalline. We demonstrate
the excitation of a propagating surface plasmon with a high plasmonic
figure of merit in both amorphous and crystalline phases of Sb2Te3 thin films. We show polarization-dependent
and -independent plasmonic resonances by fabricating one and two-dimensional
periodic nanostructures in Sb2Te3 thin films,
respectively. Moreover, we demonstrate electrically tunable plasmonic
resonances using a microheater integrated with the Sb2Te3/Si device. The developed electrically tunable Sb2Te3-based plasmonic devices could find applications in
the development of active color filters.