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Carbon-assisted growth and high visible-light optical reflectivity of amorphous silicon oxynitride nanowires.

Zhang L, Shi T, Tang Z, Liu D, Xi S, Li X, Lai W - Nanoscale Res Lett (2011)

Bottom Line: The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance.These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle.Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.

View Article: PubMed Central - HTML - PubMed

Affiliation: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China. zirong@mail.hust.edu.cn.

ABSTRACT
Large amounts of amorphous silicon oxynitride nanowires have been synthesized on silicon wafer through carbon-assisted vapor-solid growth avoiding the contamination from metallic catalysts. These nanowires have the length of up to 100 μm, with a diameter ranging from 50 to 150 nm. Around 3-nm-sized nanostructures are observed to be homogeneously distributed within a nanowire cross-section matrix. The unique configuration might determine the growth of ternary amorphous structure and its special splitting behavior. Optical properties of the nanowires have also been investigated. The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance. These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle. Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.

No MeSH data available.


TEM images of the surface and cross-section morphologies of a nanowire. (a) TEM image of a Si-O-N nanowire and the corresponding EDX analyses as an inset. (b) An HRTEM image of the nanowire's cross-section and the corresponding SAED patterns as an insert.
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Figure 2: TEM images of the surface and cross-section morphologies of a nanowire. (a) TEM image of a Si-O-N nanowire and the corresponding EDX analyses as an inset. (b) An HRTEM image of the nanowire's cross-section and the corresponding SAED patterns as an insert.

Mentions: Figure 2a, b shows typical TEM images of the surface and cross-section morphologies of a nanowire, respectively, indicating that the resulting nanowires are amorphous. The corresponding selected area electron diffraction (SAED) pattern confirms its amorphous structure shown as an inset in Figure 2b. EDX analyses shown as an inset in Figure 2a revealed that the chemical composition of the nanowire consists basically of three elements of Si, N, and O, with the ratio of approximately 2.75:1:3.60. We observed that there were homogeneously distributed nanostructures in the cross-section of the Si-O-N nanowire matrix, with a diameter of about 3 nm, shown as dark spots in Figure 2b. A similar observation was reported by D. Criado et al. in the Si-O-N film study [18]. Their study showed that the homogeneously distributed nanostructures can be found in SiO2-like Si-O-N samples, where the dark spot area might be the structure related with N element. In our study, the kind of distribution is observed in all cross-sections of Si-O-N nanowires, but none is obtained on the surface. These unique configurations might determine the growth behavior of multi-element amorphous nanowires and lead to the splitting phenomena where the branches and the trunk have the same diameter.


Carbon-assisted growth and high visible-light optical reflectivity of amorphous silicon oxynitride nanowires.

Zhang L, Shi T, Tang Z, Liu D, Xi S, Li X, Lai W - Nanoscale Res Lett (2011)

TEM images of the surface and cross-section morphologies of a nanowire. (a) TEM image of a Si-O-N nanowire and the corresponding EDX analyses as an inset. (b) An HRTEM image of the nanowire's cross-section and the corresponding SAED patterns as an insert.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211981&req=5

Figure 2: TEM images of the surface and cross-section morphologies of a nanowire. (a) TEM image of a Si-O-N nanowire and the corresponding EDX analyses as an inset. (b) An HRTEM image of the nanowire's cross-section and the corresponding SAED patterns as an insert.
Mentions: Figure 2a, b shows typical TEM images of the surface and cross-section morphologies of a nanowire, respectively, indicating that the resulting nanowires are amorphous. The corresponding selected area electron diffraction (SAED) pattern confirms its amorphous structure shown as an inset in Figure 2b. EDX analyses shown as an inset in Figure 2a revealed that the chemical composition of the nanowire consists basically of three elements of Si, N, and O, with the ratio of approximately 2.75:1:3.60. We observed that there were homogeneously distributed nanostructures in the cross-section of the Si-O-N nanowire matrix, with a diameter of about 3 nm, shown as dark spots in Figure 2b. A similar observation was reported by D. Criado et al. in the Si-O-N film study [18]. Their study showed that the homogeneously distributed nanostructures can be found in SiO2-like Si-O-N samples, where the dark spot area might be the structure related with N element. In our study, the kind of distribution is observed in all cross-sections of Si-O-N nanowires, but none is obtained on the surface. These unique configurations might determine the growth behavior of multi-element amorphous nanowires and lead to the splitting phenomena where the branches and the trunk have the same diameter.

Bottom Line: The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance.These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle.Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.

View Article: PubMed Central - HTML - PubMed

Affiliation: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China. zirong@mail.hust.edu.cn.

ABSTRACT
Large amounts of amorphous silicon oxynitride nanowires have been synthesized on silicon wafer through carbon-assisted vapor-solid growth avoiding the contamination from metallic catalysts. These nanowires have the length of up to 100 μm, with a diameter ranging from 50 to 150 nm. Around 3-nm-sized nanostructures are observed to be homogeneously distributed within a nanowire cross-section matrix. The unique configuration might determine the growth of ternary amorphous structure and its special splitting behavior. Optical properties of the nanowires have also been investigated. The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance. These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle. Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.

No MeSH data available.