飞秒激光作用下单晶硅表面载流子的超快动力学研究

发布时间：2018-05-09 16:30

本文选题：飞秒激光 + 泵浦探测　；参考：《黑龙江大学自然科学学报》2017年02期

【摘要】：利用飞秒激光泵浦-探测技术研究单晶硅在不同脉冲能量作用下的瞬态反射率变化,进而分析单晶硅表面载流子的超快动力学过程。实验所用飞秒激光脉冲宽度为120 fs,泵浦光和探测光波长分别为400和800 nm。研究结果表明:飞秒激光作用后,单晶硅表面反射率变化迅速达到峰值,然后经历一个快弛豫过程和一个慢弛豫过程。快弛豫过程包括载流子-载流子散射和载流子-光学声子散射,慢弛豫过程包括载流子复合过程和扩散过程。利用双e指数模型对实验结果进行拟合,求出双e指数系数C及快弛豫时间τf。通过实验数据对比分析发现,泵浦光脉冲能量越大,快弛豫时间越长,所占的比例越大。
[Abstract]:The transient reflectivity of monocrystalline silicon under different pulse energy was studied by femtosecond laser pumped detection technique, and the ultrafast kinetic process of carrier on the surface of monocrystalline silicon was analyzed. The femtosecond laser pulse width is 120 fs and the pump and probe wavelengths are 400 and 800 nm respectively. The results show that the surface reflectivity of monocrystalline silicon reaches its peak rapidly after femtosecond laser irradiation and then goes through a fast relaxation process and a slow relaxation process. The fast relaxation process includes carrier carrier scattering and carrier optical phonon scattering, while the slow relaxation process includes carrier recombination process and diffusion process. The double e exponential model is used to fit the experimental results, and the double e exponent coefficient C and the fast relaxation time 蟿 f are obtained. By comparing the experimental data, it is found that the larger the pump pulse energy, the longer the fast relaxation time, the larger the proportion.
【作者单位】：东北林业大学理学院;
【基金】：黑龙江省自然科学基金资助项目(F201017) 黑龙江省博士后科研启动金资助项目(LBH-Q14007)
【分类号】：TN249;TN304.12

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