基于自建的超快抽运探测实验系统，研究了化学气相沉积法生长的SnSe₂薄膜的超快载流子与声子动力学。对SnSe₂薄膜随抽运能量密度变化的载流子弛豫过程的测量结果表明该薄膜具有超快的载流子热化过程和皮秒至纳秒时间尺度的复合过程。伴随着光生载流子的超快激发和能量弛豫，SnSe₂薄膜发生晶格热化，产生了特定频率的相干声学声子。通过分析声学声子振荡信号随抽运能量密度变化的规律，揭示了SnSe₂薄膜产生的相干声学声子的特性。研究结果对SnSe₂薄膜在光电器件领域的应用研究具有一定的参考价值。

Two-dimensional Dion–Jacobson (D-J) phase perovskites are prospective photovoltaic and optoelectronic materials. To study their mechanical properties and carrier-lattice interactions, we conduct femtosecond spectroscopic experiments on the films of a D-J perovskite. After optical excitation, a ∼33meV bandgap oscillation is observed in the film by transient absorption spectroscopy. With the help of transient reflection methods, we reveal that the oscillation originates from the transport of coherent longitudinal acoustic phonons through the film. Large bandgap oscillation indicates a strong coupling between carriers and lattice, and significant bandgap modulation by strains in D-J perovskites.