Ultra-fine β-SiC quantum dots fabricated by laser ablation in reactive liquid at room temperature and their violet emission
Ultra-fine β-SiC quantum dots fabricated by laser ablation in reactive liquid at room temperature and their violet emission
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DOI：
10.1039/b909800c
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发表时间：
2009-01-01
影响因子：
--
通讯作者：
Xu, Xiaoxia
中科院分区：
文献类型：
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作者：
Yang, Shikuan;Cai, Weiping;Xu, Xiaoxia
提出了一种简单、灵活的制备超细β-SiC量子点的方法，即用激光烧蚀浸泡在乙醇中的硅片，然后进行刻蚀。所得到的β-SiC量子点几乎是单分散的，尺寸约为3.5 nm。激光烧蚀后β-SiC的相对含量取决于液相在一定激光能量密度下提供碳原子的能力。适当的液体介质与适当的碳原子供应能力，可以导致几乎纯的β-SiC在所制备的样品。所得到的β-SiC量子点在紫色区域表现出强而稳定的发射，相对于块状SiC的发射有明显的蓝移。这种大的发射蓝移归因于它们的超细尺寸引起的显著的量子限制效应。该方法可推广到其它一些通常在高温高压下形成的超细硅化合物的制备。这项研究可以提出纳米结构器件的构建模块作为紫外光源和生物分子标记的新材料。
A simple and flexible route is presented for the fabrication of ultrafine beta-SiC quantum dots (QDs) based on laser ablation of silicon wafers immersed in ethanol and subsequent etching. The obtained beta-SiC QDs are nearly monodispersed and about 3.5 nm in size. The relative content of beta-SiC after laser ablation depends on the liquid phase's ability to supply carbon atoms at a certain laser fluence. Proper liquid media with appropriate carbon atoms supply capacity can lead to nearly pure beta-SiC in the as-prepared sample. The obtained beta-SiC QDs exhibit strong and stable emission in the violet region, significantly blue-shifting relative to that of bulk SiC. This big blue shift of emission is attributed to the significant quantum confinement effect induced by their ultrafine size. This method can be extended to produce some other ultrafine Si compounds which are usually formed at high temperature and/or high pressure. This study could present the building blocks of nanostructured devices as violet light sources and new materials in biological molecular labels.