  The switching and optical properties of phase-change thin films are actively
investigated for future smart optical devices. The possibility of having more
than one stable state, the large optical contrast between phases, and the fast
and reversible switching are some attractive properties driving the research
interest. Optical devices based on phase change alloys are considered the
frontier contenders for tunable photonics. The combination of vivid structural
color formation, with partial amorphization/crystallization of phase change
alloys, and the associated optical tunability could be integrated into an
energy-efficient reflective display device with high pixel density. This work
demonstrates a contrast formation due to relative height differences from
isolated pixelated structures. A reflective heterostructure device consisting
of a low-loss Sb2Se3 alloy on a gold substrate was produced. With a focused ion
beam, a pixelated metasurface structure was produced. Moreover, the ability to
create local height differences using an ion beam was employed to create a
structural color combination mimicking traditional LED like RGB pixels. We
believe our approach in creating metapixels on phase change thin film surfaces
could open up research interest in phase change alloys and moving away from
semi/static plasmonic systems into truly dynamic display devices.
