Tailoring optical properties of silicon nanowires by Au nanostructure decorations : enhanced Raman scattering and photodetection
Author
Chen, Renjie
Li, Dehui
Hu, Hailong
Zhao, Yanyuan
Wang, Ying
Wong, Nancy
Wang, Shijie
Zhang, Yi
Hu, Jun
Shen, Zexiang
Xiong, Qihua
Date of Issue
2012School
School of Electrical and Electronic Engineering
School of Physical and Mathematical Sciences
School of Physical and Mathematical Sciences
Abstract
Metallic nanoparticles (NPs) decorated semiconductor nanowires (NWs) heterostructures show significant promise in enhanced optical and opto-electrical properties due to the coupling of surface plasmon to nanowires. Here, we demonstrate a galvanic displacement based strategy to achieve in situ nucleation of Au nanoparticles and then postgrowth into higher order Au nanostructures such as dimers, nanorods, and nanoprisms along the same Si nanowires (SiNWs). The presence of Au nanostructures significantly enhances the optical properties of nanowires. Particularly, a 24 times enhancement of Si Raman scattering signal was achieved with a Au dimer decoration. A Au nanorod aligned in parallel along nanowire strongly enhances the anisotropy of Si Raman scattering, with more than 28 times stronger signal under parallel polarization than that under perpendicular polarization, demonstrating for the first time the surface plasmon enhanced antenna effect. In addition, we demonstrate that surface plasmon enhances photocurrent of SiNW by almost 100%, which is higher than previous reports. Our studies show that SiNWs decorated with metallic nanostructures by in situ galvanic displacement exhibit significant promise toward high efficiency photodetection and light harvesting applications.
Type
Journal Article
Series/Journal Title
The journal of physical chemistry C
Collections
http://dx.doi.org/10.1021/jp210198u
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