SnSe_(2)薄膜的载流子与声子动力学研究

Carrier and phonon dynamics study of SnSe_(2) thin films

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SnSe_(2)薄膜的超快载流子与声子动力学。对SnSe_(2)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,SnSe_(2)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SnSe_(2)薄膜产生的相干声学声子的特性。研究结果对SnSe_(2)薄膜在光电器件领域的应用研究具有一定的参考价值。

The ultrafast carrier and phonon dynamics of SnSe_(2)thin films grown by chemical vapor deposition are investigated based on a self-built ultrafast pump-probe experimental system.By measuring the carrier relaxation process of the SnSe_(2)thin films with the variation of pumping energy density,the results showed that the thin films had an ultrafast carrier thermalization process and a composite process on the picosecond to nanosecond time scale.Accompanied by the ultrafas excitation and energy relaxation of photogenerated carriers,the SnSe_(2)thin films underwent lattice thermalization and generated coherent acoustic phonons of specific frequencies.The properties of the coherent acoustic phonons generated by the SnSe_(2)thin films were revealed by analyzing the variation of the acoustic phonon oscillation signal with the pumping energy density.The results of this study provide reference value for the study of the application of SnSe_(2)thin films in the field of optoelectronic devices.