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Grassy Silica Nanoribbons and Strong Blue Luminescence

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ABSTRACT

Silicon dioxide (SiO2) is one of the key materials in many modern technological applications such as in metal oxide semiconductor transistors, photovoltaic solar cells, pollution removal, and biomedicine. We report the accidental discovery of free-standing grassy silica nanoribbons directly grown on SiO2/Si platform which is commonly used for field-effect transistors fabrication without other precursor. We investigate the formation mechanism of this novel silica nanostructure that has not been previously documented. The silica nanoribbons are flexible and can be manipulated by electron-beam. The silica nanoribbons exhibit strong blue emission at about 467 nm, together with UV and red emissions as investigated by cathodoluminescence technique. The origins of the luminescence are attributed to various defects in the silica nanoribbons; and the intensity change of the blue emission and green emission at about 550 nm is discussed in the frame of the defect density. Our study may lead to rational design of the new silica-based materials for a wide range of applications.

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Morphology of silica nanoribbons.(a) Typical SHIM image of bunches of silica nanoribbons. (b,c) TEM images of silica nanoribbons. (d,e) Topographic AFM images and line-profiles showing the thickness of nanoribbons.
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f1: Morphology of silica nanoribbons.(a) Typical SHIM image of bunches of silica nanoribbons. (b,c) TEM images of silica nanoribbons. (d,e) Topographic AFM images and line-profiles showing the thickness of nanoribbons.

Mentions: Figure 1a shows a representative Helium ion microscopy (HIM)18 image of the silica nanoribbons grown on SiO2/Si substrate. The gatherings of nanoribbons with a length of tens of micrometers and varying widths resemble bunches of chlorophytum comosum planting into the ground. We further transferred several nanoribbons from the SiO2/Si substrate onto transmission electron microscope (TEM) Cu meshes to investigate the fine microstructures of the nanoribbons. As displayed in Fig. 1b, the silica nanoribbons are electron-transparent. No ordered structure is observed in the high-resolution TEM image (Fig. 1c and Figure S1 in Supp. Info.), suggesting an amorphous nature of the silica nanoribbons. We had also annealed the nanoribbons for 2 h at 1000. However, amorphous to crystalline structure transition did not occur. The amorphous feature of the nanoribbons is confirmed by the X-ray diffraction (XRD) pattern of the samples (see Figure S2, Supp. Info.). This phenomenon could be attributed to the multilayered structure of the silica nanoribbons, since it has been reported that growing additional layers on top of the crystalline silica monolayer would finally result in amorphous silica films19. The thickness of individual nanoribbons based on atomic force microscopy (AFM) measurements ranges from 5.4 nm (Fig. 1e) to approximately 50 nm, becoming thinner along the growth direction of the grassy nanoribbons (Fig. 1d,e).


Grassy Silica Nanoribbons and Strong Blue Luminescence
Morphology of silica nanoribbons.(a) Typical SHIM image of bunches of silica nanoribbons. (b,c) TEM images of silica nanoribbons. (d,e) Topographic AFM images and line-profiles showing the thickness of nanoribbons.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5035931&req=5

f1: Morphology of silica nanoribbons.(a) Typical SHIM image of bunches of silica nanoribbons. (b,c) TEM images of silica nanoribbons. (d,e) Topographic AFM images and line-profiles showing the thickness of nanoribbons.
Mentions: Figure 1a shows a representative Helium ion microscopy (HIM)18 image of the silica nanoribbons grown on SiO2/Si substrate. The gatherings of nanoribbons with a length of tens of micrometers and varying widths resemble bunches of chlorophytum comosum planting into the ground. We further transferred several nanoribbons from the SiO2/Si substrate onto transmission electron microscope (TEM) Cu meshes to investigate the fine microstructures of the nanoribbons. As displayed in Fig. 1b, the silica nanoribbons are electron-transparent. No ordered structure is observed in the high-resolution TEM image (Fig. 1c and Figure S1 in Supp. Info.), suggesting an amorphous nature of the silica nanoribbons. We had also annealed the nanoribbons for 2 h at 1000. However, amorphous to crystalline structure transition did not occur. The amorphous feature of the nanoribbons is confirmed by the X-ray diffraction (XRD) pattern of the samples (see Figure S2, Supp. Info.). This phenomenon could be attributed to the multilayered structure of the silica nanoribbons, since it has been reported that growing additional layers on top of the crystalline silica monolayer would finally result in amorphous silica films19. The thickness of individual nanoribbons based on atomic force microscopy (AFM) measurements ranges from 5.4 nm (Fig. 1e) to approximately 50 nm, becoming thinner along the growth direction of the grassy nanoribbons (Fig. 1d,e).

View Article: PubMed Central - PubMed

ABSTRACT

Silicon dioxide (SiO2) is one of the key materials in many modern technological applications such as in metal oxide semiconductor transistors, photovoltaic solar cells, pollution removal, and biomedicine. We report the accidental discovery of free-standing grassy silica nanoribbons directly grown on SiO2/Si platform which is commonly used for field-effect transistors fabrication without other precursor. We investigate the formation mechanism of this novel silica nanostructure that has not been previously documented. The silica nanoribbons are flexible and can be manipulated by electron-beam. The silica nanoribbons exhibit strong blue emission at about 467 nm, together with UV and red emissions as investigated by cathodoluminescence technique. The origins of the luminescence are attributed to various defects in the silica nanoribbons; and the intensity change of the blue emission and green emission at about 550 nm is discussed in the frame of the defect density. Our study may lead to rational design of the new silica-based materials for a wide range of applications.

No MeSH data available.