2023/08/08 by Simon Wredh, Yunzheng Wang, Wredh, Simon +5 · 1 citation
Engineering · Materials Science · #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Optical Polarization and Ellipsometry #Optics (physics.optics) #Phase-change materials and chalcogenides
paper · pdf · doi:10.48550/arxiv.2308.04295
openalex publication_date 2023/08/08 · openalex created_date 2023/08/18 · openalex updated_date 2026/07/28
The optical properties of phase-change materials (PCM) can be tuned to multiple levels by controlling the transition between their amorphous and crystalline phases. In multi-material PCM structures, the number of discrete reflectance levels can be increased according to the number of PCM layers. However, the effect of increasing number of layers on quenching and reversibility has not been thoroughly studied. In this work, the phase-change physics and thermal conditions required for reversible switching of single and multi-material PCM switches are discussed based on thermo-optical phase-change models and laser switching experiments. By using nanosecond laser pulses, 16 different reflectance levels in Ge2Sb2Te5 are demonstrated via amorphization. Furthermore, a multi-material switch based on Ge2Sb2Te5 and GeTe with four discrete reflectance levels is experimentally proven with a reversible multi-level response. The results and design principles presented herein will impact active photonics applications that rely on dynamic multi-level operation, such as optical computing, beam steering, and next-generation display technologies.