近红外飞秒激光诱导非晶硅薄膜的晶化

摘要

1kHz的飞秒激光辐照在非晶硅薄膜后会使得辐照区域的薄膜产生晶化现象.拉曼光谱表明这个激光诱导晶化过程与入射激光的能量及其模式分布有密切的联系.扫描电镜观测发现激光辐照区域形成了粗糙的表面纹理,并且大量的晶粒形成在这个结构表面.这个晶化现象可能是由于爆炸晶化成核和晶粒外延生长共同作用的结果,进一步的研究表明这种飞秒激光诱导的晶化结构能够增进该薄膜在可见和红外波段的光学吸收.%1 kHz femtosecond laser was used to induce crystallization on amorphous Si film. Raman spectra show that the crystallization region depended critically on the laser fluence and profile. Furthermore, a textured surface with a mass of fine-grained crystalline Si was observed through SEM. This structure might result from the explosive crystallization and epitaxial growth of Si nucleation on the interface of liquid-solid Si. Due to the simultaneous process of crystallization and surface texturing, this laser treated region enhanced its absorbance in the visible and infrared band.