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Novel, low-cost solid-liquid-solid process for the synthesis of α-Si3N4 nanowires at lower temperatures and their luminescence properties.

Liu H, Huang Z, Huang J, Fang M, Liu YG, Wu X, Hu X, Zhang S - Sci Rep (2015)

Bottom Line: The growth of the nanowires was governed by the solid-liquid-solid (SLS) mechanism.The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectra showed that the optical properties of the α-Si3N4 nanowires can be changed along with the excitation wavelength or the excitation light source.This work can be useful, not only for simplifying the design and synthesis of Si-related nanostructures, but also for developing new generation nanodevices with changeable photoelectronic properties.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Technology, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, China University of Geosciences (Beijing), 100083, P. R. China.

ABSTRACT
Ultra-long, single crystal, α-Si3N4 nanowires sheathed with amorphous silicon oxide were synthesised by an improved, simplified solid-liquid-solid (SLS) method at 1150 °C without using flowing gases (N2, CH4, Ar, NH3, etc.). Phases, chemical composition, and structural characterisation using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM/HRTEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) showed that the nanowires had Si3N4@SiOx core-shell structures. The growth of the nanowires was governed by the solid-liquid-solid (SLS) mechanism. The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectra showed that the optical properties of the α-Si3N4 nanowires can be changed along with the excitation wavelength or the excitation light source. This work can be useful, not only for simplifying the design and synthesis of Si-related nanostructures, but also for developing new generation nanodevices with changeable photoelectronic properties.

No MeSH data available.


Related in: MedlinePlus

(a–b) SE and CL images of the α-Si3N4 nanowires; (c) Room-temperature CL spectra of α-Si3N4 nanowires with a focused electron beam at an accelerating voltage of 30 kV.
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f7: (a–b) SE and CL images of the α-Si3N4 nanowires; (c) Room-temperature CL spectra of α-Si3N4 nanowires with a focused electron beam at an accelerating voltage of 30 kV.

Mentions: To visualise the spatial distribution of the luminescence from these α-Si3N4 nanowires, the secondary electron (SE) image and corresponding CL image were recorded as shown in Fig. 7a–b. Figure 7c shows the room temperature CL spectrum of the products. As shown in Fig. 7c, the histogram is the as-obtained spectrum, and the red and blue lines are simulated data plots. The nanowire spectra showed two peaks at approximately 368 nm (3.37 eV) and 567 nm (2.19 eV). Previous studies suggested that the optical properties of nanostructured materials can be affected by many factors, such as intrinsic characteristics, composition, shape and size of nanomaterial, structural defects, and impurities4445. Hu et al.46 reported the CL spectrum of an α-Si3N4 microribbon, which consists of one intense UV emission peak at approximately 305 nm (4.06 eV) and two weak broad peaks at around 540 nm (2.30 eV) and 735 nm (1.68 eV). They considered the 305 nm peak as being due to recombination, either from the conduction band to the N20 level, or from the valance band to the N4+ level: the 540 nm peak is attributed to a recombination process at the silicon dangling bond, and the 735 nm peak is caused by recombination between the N4+ and N20 levels46. Huang et al.47 synthesised α-Si3N4 nanobelts, nanowires, and nanobranches and compared the CL properties of these three nanostructures. They propose that the UV-blue emissions of their α-Si3N4 nanobelt, nanowire, and nanobranch centred with a band from 3.05 eV to 3.34 eV should arise from a recombination between the Si-Si σ* level and the N20, and N20, levels, or between the N4+ and intrinsic valence band edge47.


Novel, low-cost solid-liquid-solid process for the synthesis of α-Si3N4 nanowires at lower temperatures and their luminescence properties.

Liu H, Huang Z, Huang J, Fang M, Liu YG, Wu X, Hu X, Zhang S - Sci Rep (2015)

(a–b) SE and CL images of the α-Si3N4 nanowires; (c) Room-temperature CL spectra of α-Si3N4 nanowires with a focused electron beam at an accelerating voltage of 30 kV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660443&req=5

f7: (a–b) SE and CL images of the α-Si3N4 nanowires; (c) Room-temperature CL spectra of α-Si3N4 nanowires with a focused electron beam at an accelerating voltage of 30 kV.
Mentions: To visualise the spatial distribution of the luminescence from these α-Si3N4 nanowires, the secondary electron (SE) image and corresponding CL image were recorded as shown in Fig. 7a–b. Figure 7c shows the room temperature CL spectrum of the products. As shown in Fig. 7c, the histogram is the as-obtained spectrum, and the red and blue lines are simulated data plots. The nanowire spectra showed two peaks at approximately 368 nm (3.37 eV) and 567 nm (2.19 eV). Previous studies suggested that the optical properties of nanostructured materials can be affected by many factors, such as intrinsic characteristics, composition, shape and size of nanomaterial, structural defects, and impurities4445. Hu et al.46 reported the CL spectrum of an α-Si3N4 microribbon, which consists of one intense UV emission peak at approximately 305 nm (4.06 eV) and two weak broad peaks at around 540 nm (2.30 eV) and 735 nm (1.68 eV). They considered the 305 nm peak as being due to recombination, either from the conduction band to the N20 level, or from the valance band to the N4+ level: the 540 nm peak is attributed to a recombination process at the silicon dangling bond, and the 735 nm peak is caused by recombination between the N4+ and N20 levels46. Huang et al.47 synthesised α-Si3N4 nanobelts, nanowires, and nanobranches and compared the CL properties of these three nanostructures. They propose that the UV-blue emissions of their α-Si3N4 nanobelt, nanowire, and nanobranch centred with a band from 3.05 eV to 3.34 eV should arise from a recombination between the Si-Si σ* level and the N20, and N20, levels, or between the N4+ and intrinsic valence band edge47.

Bottom Line: The growth of the nanowires was governed by the solid-liquid-solid (SLS) mechanism.The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectra showed that the optical properties of the α-Si3N4 nanowires can be changed along with the excitation wavelength or the excitation light source.This work can be useful, not only for simplifying the design and synthesis of Si-related nanostructures, but also for developing new generation nanodevices with changeable photoelectronic properties.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Technology, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, China University of Geosciences (Beijing), 100083, P. R. China.

ABSTRACT
Ultra-long, single crystal, α-Si3N4 nanowires sheathed with amorphous silicon oxide were synthesised by an improved, simplified solid-liquid-solid (SLS) method at 1150 °C without using flowing gases (N2, CH4, Ar, NH3, etc.). Phases, chemical composition, and structural characterisation using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM/HRTEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) showed that the nanowires had Si3N4@SiOx core-shell structures. The growth of the nanowires was governed by the solid-liquid-solid (SLS) mechanism. The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectra showed that the optical properties of the α-Si3N4 nanowires can be changed along with the excitation wavelength or the excitation light source. This work can be useful, not only for simplifying the design and synthesis of Si-related nanostructures, but also for developing new generation nanodevices with changeable photoelectronic properties.

No MeSH data available.


Related in: MedlinePlus