High-stability and low-noise multilevel switching in In${}_3$SbTe${}_2$ material for phase change photonic memory applications

Herein, eight uniform optical states (3 bit) are demonstrated by irradiating nanosecond laser pulses on thin In${}_3$SbTe${}_2$ films having high stability (260 °C), revealing at least 1% reflectivity contrast between any two consecutive states with strikingly low noise variation of 0.18% at each level, which is almost a 50% lower value compared to Ge${}_2$Sb${}_2$Te${}_5$ and AgInSbTe materials, revealing the two times enhanced signal-to-noise ratio of the In${}_3$SbTe${}_2$ material. Furthermore, a systematic structural evolution during multilevel switching is investigated using confocal Raman spectroscopic studies. The experimental findings demonstrate low-noise yet highly stable multilevel switching toward the development of reliable phase change photonic memory devices. (© 2020 Wiley‐VCH GmbH)