Structural Phase Transitions between Layered Indium Selenide for Integrated Photonic Memory
Structural Phase Transitions between Layered Indium Selenide for Integrated Photonic Memory
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DOI：
10.1002/adma.202108261
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发表时间：
2022-05-20
影响因子：
29.4
通讯作者：
Gu, Tingyi
中科院分区：
文献类型：
--
作者：
Li, Tiantian;Wang, Yong;Gu, Tingyi
光学存储器件的主要机制依赖于非晶态和晶态之间的相变。光学相变材料中缓慢或耗能的非晶-晶态转变对器件的可扩展性和性能是不利的。利用一个集成的光子平台，演示了由单个纳秒脉冲触发的两种层状结构的硒化铟(In2Se3)之间的非易失性和可逆开关。高分辨对分布函数揭示了层状结构之间详细的原子跃迁路径。通过层间“剪切滑移”和等对称相变，α-和β-结构态之间的转换包含低的重新组态熵，允许在层状结构之间进行可逆转换。在分子束外延生长的薄膜中对晶体-晶体相变中的宽带折射率对比度、光学透明度和体积效应进行了实验表征，并与从头计算进行了比较。由1.5微米长的In2Se_3覆盖层引入的非线性谐振器透射谱测量的线损耗率增量为3.3 GHz，这是材料吸收和散射共同作用的结果。
The primary mechanism of optical memoristive devices relies on phase transitions between amorphous and crystalline states. The slow or energy-hungry amorphous-crystalline transitions in optical phase-change materials are detrimental to the scalability and performance of devices. Leveraging an integrated photonic platform, nonvolatile and reversible switching between two layered structures of indium selenide (In2Se3) triggered by a single nanosecond pulse is demonstrated. The high-resolution pair distribution function reveals the detailed atomistic transition pathways between the layered structures. With interlayer "shear glide" and isosymmetric phase transition, switching between the alpha- and beta-structural states contains low re-configurational entropy, allowing reversible switching between layered structures. Broadband refractive index contrast, optical transparency, and volumetric effect in the crystalline-crystalline phase transition are experimentally characterized in molecular-beam-epitaxy-grown thin films and compared to ab initio calculations. The nonlinear resonator transmission spectra measure of incremental linear loss rate of 3.3 GHz, introduced by a 1.5 mu m-long In2Se3-covered layer, resulted from the combinations of material absorption and scattering.