High-Stability and Low-Noise Multilevel Switching in In<inf>3</inf>SbTe<inf>2</inf> Material for Phase Change Photonic Memory Applications

Herein, eight uniform optical states (3 bit) are demonstrated by irradiating nanosecond laser pulses on thin In3SbTe2 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 Ge2Sb2Te5 and AgInSbTe materials, revealing the two times enhanced signal-to-noise ratio of the In3SbTe2 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.