One-step growth of needle and dendritic gold nanostructures on silicon for surface enhanced Raman scattering
One-step growth of needle and dendritic gold nanostructures on silicon for surface enhanced Raman scattering
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DOI：
10.1039/c1ce05912b
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发表时间：
2012-01-01
期刊：
影响因子：
3.1
通讯作者：
Park, Hyonkook
中科院分区：
文献类型：
--
作者：
Lahiri, Abhishek;Wen, Rui;Park, Hyonkook
采用电偶置换的方法在n型和p型硅上实现了金纳米结构的光诱导沉积。在沉积过程中，用530 nm激光照射n型硅，观察到了簇状沉积，而用635 nm激光照射，则形成了金纳米针。相比之下，在p型硅上沉积金得到了平坦的树枝状结构，在有光或无光的情况下没有观察到明显的形貌变化。在黑暗中，只有不规则的金簇形成。光对形貌变化的影响与金原子核的表面等离子体共振以及硅导带中存在的过剩电荷有关。为了评价衬底的传感性能，对金属-半导体对进行了拉曼光谱检测。在这些衬底中，金针硅对的表面增强拉曼散射(SERS)增强作用最强。从SERS测量也可以得出结论，金属-半导体界面在增强SERS信号方面起着重要作用。
Light-induced deposition of gold nanostructures onto both n-type and p-type silicon was performed by galvanic displacement. On illuminating the n-type silicon with a 530 nm laser during the deposition process, a clustered deposit was observed whereas on using a 635 nm laser, gold nano-needles were formed. In comparison, on depositing gold on p-type silicon, flat dendritic structures were obtained and no significant changes in morphology were observed in the presence or absence of light. In the dark, only irregular gold clusters formed. The influence of light in changing the morphology was related to the surface plasmon resonance of the gold nuclei as well as the excess charge present in the conduction band of the silicon. To evaluate the sensoric property of the substrates, Raman spectroscopy was conducted on the metal-semiconductor couple for the detection of ruthenium red molecule. Among the substrates, the gold needle-silicon couple gave the highest surface enhanced Raman scattering (SERS) enhancement. We could also conclude from the SERS measurements that the metal-semiconductor interface plays an important role in increasing the SERS signal.