Synthesis of Si/SiO2 core–shell nanowire arrays and broadband anti-reflection effects in diluted Si nanowire arrays by adjusting dielectric shell thickness
| Autor: | Xinhua Li, Bukang Zhou, Long Wen, Yuqi Wang, Tongfei Shi, Guangqiang Liu, Huaxiang Cao, Tao Chen |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Fabrication business.industry Mechanical Engineering Nanowire Shell (structure) Bioengineering Nanotechnology 02 engineering and technology General Chemistry Dielectric 021001 nanoscience & nanotechnology 01 natural sciences 010309 optics Core (optical fiber) Reflection (mathematics) Mechanics of Materials 0103 physical sciences Optoelectronics Nanosphere lithography General Materials Science Electrical and Electronic Engineering 0210 nano-technology business Absorption (electromagnetic radiation) |
| Zdroj: | Nanotechnology. 28:185402 |
| ISSN: | 1361-6528 0957-4484 |
| DOI: | 10.1088/1361-6528/aa66b4 |
| Popis: | A low filling ratio and enhanced absorption is needed to enable the full potential of Si nanowire (NW) arrays for optoelectronic applications. In this paper, we report a versatile, scalable fabrication technique that uses nanosphere lithography (NSL) patterning for the synthesis of vertically aligned Si and Si/SiO2 NW arrays. The optical reflection of the NW arrays can be substantially suppressed by the addition of the transparent shell. Meanwhile, by the finite-difference time-domain (FDTD) simulation, we find that the absorption enhancement in the core Si NW can be obtained by adding the transparent shell. The special absorption enhancement of the Si NW arrays with a core-shell structure can be theoretically understood by modal analysis. The absorption in such Si NW array structures is very sensitive to the thickness of transparent coating. By the addition of a SiO2 shell layer, the absorption in the inner Si NW array can be substantially enhanced. Furthermore, significant absorption enhancement and broadband anti-reflection effects can be achieved by the diluted Si NWs combined with the single dielectric shell. |
| Databáze: | OpenAIRE |
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