Optical characterization of ultrasmall Si nanoparticles prepared through electrochemical dispersion of bulk Si.
Optical characterization of ultrasmall Si nanoparticles prepared through electrochemical dispersion of bulk Si.
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通过电化学分散体硅制备的超小硅纳米颗粒的光学表征。
DOI：
10.1021/jp052214e
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Braun,PaulV
中科院分区：
文献类型：
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作者：
Eckhoff,DeanA;Sutin,JasonDB;Clegg,RobertM;Gratton,Enrico;Rogozhina,ElenaV;Braun,PaulV
研究硅纳米粒子（Si-np）在水环境中的性质和稳定性可能会导致在生物系统中的新应用。在这项工作中，我们使用吸收和光致发光（PL）光谱表征超小硅-NP通过阳极蚀刻和超声波分馏的结晶硅晶片制备。他们的行为进行了研究，随着时间的推移，在2-丙醇和处理过程中与水，氢氧化钠，盐酸和过氧化氢。观察到的人口分为两种类型的材料：明亮的物种组成的蚀刻良好的Si-np，直径为1.1纳米，和黑暗的物种来自部分蚀刻或聚集的Si结构。黑色物质通过其在2-丙醇和水溶液中的散射而可见，并且通过用NaOH或HCl处理沉淀而大部分被去除。明亮的材料包括三种不同的物质，它们各自的发射光谱在UV−B、UV−A和硬蓝区域。硬蓝PL显示出具有简单的pH依赖性，pKa = 3，提供了一个重要的洞察其化学起源和可能的应用Si-np作为环境探针的信号。我们的研究结果提供了一些潜在的定制的PL性能的超小Si-NP通过控制其表面化学。
Studying the properties and stability of silicon nanoparticles (Si-np) in aqueous environments may lead to novel applications in biological systems. In this work, we use absorption and photoluminescence (PL) spectroscopy to characterize ultrasmall Si-np prepared through anodic etching and ultrasonic fractionation of a crystalline Si wafer. Their behavior is studied over time in 2-propanol and during treatments with water, NaOH, HCl, and H2O2. The observed population is divided into two types of material: bright species consisting of well-etched Si-np, ∼1 nm in diameter, and dark species derived from partially etched or aggregated Si structures. The dark material is seen by its scattering in the 2-propanol and water solutions and is largely removed via precipitation with the NaOH or HCl treatment. The bright material includes three distinct species with their respective emissions in the UV−B, UV−A, and hard-blue regions of the spectrum. The hard-blue PL is shown to have a simple pH dependence with a pKa∼3, providing an important insight into its chemical origin and signaling for possible application of Si-np as environmental probes. Our results offer some potential for tailoring the PL properties of ultrasmall Si-np through control of their surface chemistry.