As one of the most successful nonvolatile phase change materials (PCMs), Ge₂Sb₂Te₅ (GST) can be reversibly switched between amorphous and crystalline phases by nanosecond laser pulses, which enables its applications in optical disks and various emerging reconfigurable photonic devices. Instead of simply inducing temperature rising of GST thin film via light absorption, high-energy laser irradiation leads to modifications of molecular bonds, forming different local structures. We employed a nanosecond pulse laser with different pulse duration, energy and pulse numbers to induce multi-level switching of GST thin films. By employing Raman spectroscopy, we illustrated that GeTe_4–nGe_n (n = 0, 1, 2) subsystem plays a decisive role in laser-induced crystallization of GST. Different from isothermal annealing, where Sb_mTe₃ (m = 1, 2) subsystem contributes as well. This is evidenced by the suppression of Sb_mTe₃ structure of an isothermally annealed film treated with additional laser crystallization. In addition, our investigations indicated that in GeTe_4–nGe_n subsystem, Joule heating promotes the formation of Te-rich tetrahedral components. These findings provide more insights into the structural characteristics of GST.

作为最成功的非易失性相变材料 (PCM) 之一，Ge ₂ Sb ₂ Te ₅ (GST) 可以通过纳秒激光脉冲在非晶相和晶相之间可逆地切换，从而使其在光盘和各种新兴的可重构光子器件中得到应用. 高能激光照射不是简单地通过光吸收引起 GST 薄膜的温度升高，而是导致分子键的修饰，形成不同的局部结构。我们采用具有不同脉冲持续时间、能量和脉冲数的纳秒脉冲激光器来诱导 GST 薄膜的多级切换。通过使用拉曼光谱，我们说明了的GeTe _{4 -n}戈_ñ（ñ = 0, 1, 2) 子系统在 GST 的激光诱导结晶中起决定性作用。与等温退火不同，其中 Sb _m Te ₃ ( m  = 1, 2) 子系统也有贡献。这可以通过用额外的激光结晶处理的等温退火膜的 Sb _m Te ₃结构的抑制来证明。此外，我们的调查表明，在的GeTe _{4 -n}戈_ñ子系统，焦耳热促进富Te四面体成分的形成。这些发现为 GST 的结构特征提供了更多见解。