We report self-organized periodic nanostructures on amorphous silicon thin flms by femtosecond laser-induced oxidation.The dependence of structural periodicity on the thickness of silicon flms and the substrate materi...We report self-organized periodic nanostructures on amorphous silicon thin flms by femtosecond laser-induced oxidation.The dependence of structural periodicity on the thickness of silicon flms and the substrate materials is investigated.The results reveal that when silicon flm is 200 nm,the period of self-organized nanostructures is close to the laser wavelength and is insensitive to the substrates.In contrast,when the silicon flm is 50 nm,the period of nanostructures is much shorter than the laser wavelength,and is dependent on the substrates.Furthermore,we demonstrate that,for the thick silicon flms,quasi-cylindrical waves dominate the formation of periodic nanostructures,while for the thin silicon flms,the formation originates from slab waveguide modes.Finite-diference time-domain method-based numerical simulations support the experimental discoveries.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12004314 and 62105269)LPS was supported by the Open Project Program of the Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF004)the Zhejiang Provincial Natural Science Foundation of China(No.Q21A040010).
文摘We report self-organized periodic nanostructures on amorphous silicon thin flms by femtosecond laser-induced oxidation.The dependence of structural periodicity on the thickness of silicon flms and the substrate materials is investigated.The results reveal that when silicon flm is 200 nm,the period of self-organized nanostructures is close to the laser wavelength and is insensitive to the substrates.In contrast,when the silicon flm is 50 nm,the period of nanostructures is much shorter than the laser wavelength,and is dependent on the substrates.Furthermore,we demonstrate that,for the thick silicon flms,quasi-cylindrical waves dominate the formation of periodic nanostructures,while for the thin silicon flms,the formation originates from slab waveguide modes.Finite-diference time-domain method-based numerical simulations support the experimental discoveries.
