Silicon Nanocrystals Prepared by Femtosecond Laser Ablation in solution under different ablation time

2017 International Symposium on Application of Materials Science and Energy Materials

材料科学;能源学

Yu, Jingyang^1 ; Hao, Huilian^1 ; Zhang, Rong^1 ; Zheng, Wenxiang^1 ; Wu, Wenshun^1

School of Material Engineering, Shanghai University of Engineering Science, Shanghai, China^1

关键词: FT-IR spectrum;    Localized exciton;    Organic molecules;    Room-temperature photoluminescence;    Silicon nanocrystals;    Spherical silicon;    Surface passivation;    Yield increase;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/322/2/022049/pdf
DOI  :  10.1088/1757-899X/322/2/022049

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Spherical silicon (Si) nano-crystals (NCs) were prepared through pulsed femtosecond laser ablating of porous silicon power immersed in 1-hexene. Compared to bulk Si, Raman spectra of Si NCs show a redshift and an asymmetrical broadening. High resolution transmission electron microscopy measurements show that Si particles were dispersed uniformly in 1-hexene. FTIR spectra showed that the Si nanoparticles were passivated by organic molecules. Based on the room temperature photoluminescence (PL) excitation and PL decay curves, we assign blue PL to localized excitons through oxygen associated surface states from the colloids Si NCs. Because of the good surface passivation for colloidal silicon NCs, the quantum yield increases with extending ablation time.