纳米棒
半导体
材料科学
拉曼散射
基质(水族馆)
光电子学
共振(粒子物理)
拉曼光谱
纳米技术
光学
粒子物理学
海洋学
物理
地质学
作者
Lili Yang,Yusi Peng,Yong Yang,Jianjun Li,Haoliang Huang,Yu Bao,Jimin Zhao,Yalin Lu,Zhengren Huang,Zhiyuan Li,John R. Lombardi
标识
DOI:10.1002/advs.201900310
摘要
Recent achievements in semiconductor surface-enhanced Raman scattering (SERS) substrates have greatly expanded the application of SERS technique in various fields. However, exploring novel ultra-sensitive semiconductor SERS materials is a high-priority task. Here, a new semiconductor SERS-active substrate, Ta2O5, is developed and an important strategy, the "coupled resonance" effect, is presented, to optimize the SERS performance of semiconductor materials by energy band engineering. The optimized Mo-doped Ta2O5 substrate exhibits a remarkable SERS sensitivity with an enhancement factor of 2.2 × 107 and a very low detection limit of 9 × 10-9 m for methyl violet (MV) molecules, demonstrating one of the highest sensitivities among those reported for semiconductor SERS substrates. This remarkable enhancement can be attributed to the synergistic resonance enhancement of three components under 532 nm laser excitation: i) MV molecular resonance, ii) photoinduced charge transfer resonance between MV molecules and Ta2O5 nanorods, and iii) electromagnetic enhancement around the "gap" and "tip" of anisotropic Ta2O5 nanorods. Furthermore, it is discovered that the concomitant photoinduced degradation of the probed molecules in the time-scale of SERS detection is a non-negligible factor that limits the SERS performance of semiconductors with photocatalytic activity.
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