论文标题
超快光诱导的SNSE相变
Ultrafast Photo-induced Phase Change in SnSe
论文作者
论文摘要
时间分辨的多纹兹（THZ）光谱法用于观察由带有1.55 eV泵泵光子的频率激发驱动的SNSE中超快的非热电子相变。发现瞬态THZ光电传入频谱类似Lorentzian，表明电荷定位和相位分离。光电导率的上升本质上是双峰的，由于激发到多个频段和随后的间隔散射，因此既有快速和缓慢的成分。由于光诱导的相位分离和带隙的宏观塌陷，THZ电导率的幅度，动力学和光谱在临界激发通量约为6 mJ/cm^2处的特征发生了巨大变化。
Time-resolved multi-terahertz (THz) spectroscopy is used to observe an ultrafast, non-thermal electronic phase change in SnSe driven by interband photoexcitation with 1.55 eV pump photons. The transient THz photoconductivity spectrum is found to be Lorentzian-like, indicating charge localization and phase segregation. The rise of photoconductivity is bimodal in nature, with both a fast and slow component due to excitation into multiple bands and subsequent intervalley scattering. The THz conductivity magnitude, dynamics, and spectra show a drastic change in character at a critical excitation fluence of approximately 6 mJ/cm^2 due to a photo-induced phase segregation and a macroscopic collapse of the band gap.
