Bakan, G.Ayas S.Saidzoda, T.Celebi, K.Dana, A.2018-04-122018-04-122016-080003-6951http://hdl.handle.net/11693/36648Metal surfaces coated with ultrathin lossy dielectrics enable color generation through strong interferences in the visible spectrum. Using a phase-change thin film as the coating layer offers tuning the generated color by crystallization or re-amorphization. Here, we study the optical response of surfaces consisting of thin (5-40 nm) phase-changing Ge2Sb2Te5 (GST) films on metal, primarily Al, layers. A color scale ranging from yellow to red to blue that is obtained using different thicknesses of as-deposited amorphous GST layers turns dim gray upon annealing-induced crystallization of the GST. Moreover, when a relatively thick (>100 nm) and lossless dielectric film is introduced between the GST and Al layers, optical cavity modes are observed, offering a rich color gamut at the expense of the angle independent optical response. Finally, a color pixel structure is proposed for ultrahigh resolution (pixel size: 5 × 5 μm2), non-volatile displays, where the metal layer acting like a mirror is used as a heater element. The electrothermal simulations of such a pixel structure suggest that crystallization and re-amorphization of the GST layer using electrical pulses are possible for electrothermal color tuning.EnglishAluminumAmorphizationCoatingsDielectric filmsDielectric materialsMetalsPixelsThin filmsTuningAngle-independentElectro-thermal simulationInduced crystallizationLossless dielectricsLossy dielectricsPhase change thin filmsStrong interferenceUltrahigh resolutionColorArticle10.1063/1.4961368