Mg-doped ZnO radial spherical structures with nanorods grown on both sides of the spherical shell were successfully prepared via chemical vapor deposition （CVD） of Zn and Mg powders in the absence of a catalyst. The...Mg-doped ZnO radial spherical structures with nanorods grown on both sides of the spherical shell were successfully prepared via chemical vapor deposition （CVD） of Zn and Mg powders in the absence of a catalyst. The structures associated with different growth temperatures （700, 800, and 850°C） were monitored by scanning electron microscopy （SEM）, and the result shows that the length of the nanorods increase progressively with the growth temperature increasing. X-ray diffraction （XRD） shows that the as-obtained samples can be indexed to high crystallinity with wurtzite structure. The growth of the nanostructures mainly depends on the formation of sphere-like Mg-doped Zn droplets before adding oxygen. Photoluminescence （PL） spectra that show a 39 meV blue shift indicates that the band gap becomes large, because Mg substitutes Zn in the lattice.展开更多
The hydrophobic films of TixOy-CmHn deposited from mixture gases of titanium isopropoxide (TTIP) and oxygen by plasma enhanced chemical vapor deposition (PECVD) were investigated. The films were investigated by scanni...The hydrophobic films of TixOy-CmHn deposited from mixture gases of titanium isopropoxide (TTIP) and oxygen by plasma enhanced chemical vapor deposition (PECVD) were investigated. The films were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectrometer (FTIR), X-Ray diffraction (XRD), element analysis (EA), ultraviolet visible spectrometer (UV-Vis), and water contact angle (WCA). The results reveal that the surface of the films is formed by microsized papillaes aggregated by inorganic and organic phases of complex nanoparticles with size from 50 nm to 200 nm when the discharge power is increased from 40 W to 150 W. All films demonstrate the strong broad of Ti-O-Ti stretching vibration at 400-800 cm-1, -CH bending vibration at 1388 cm-1, and broadening -OH stretching vibration at 3000-3500 cm-1. With the increase of the discharge power, the as-deposited film changes from amorphous to crystallization. The WCA of the film can be as high as 160°, indicating the hydrophobicity. The films show a similar ultraviolet absorption property as the bulk TiO2 film. The composition of the composition of film deposited at 150 W can be formulated as Ti0.3O2-C1.5H3. Therefore, the composition formula of this hydrophobic film could be expressed as TiO2-C5H10O4.7. It is believed that the complex micro/nano structures of TiO2 and C5H10O4.7 residues are responsible for the observed hydrophobicity and the ultraviolet absorption property of the film.展开更多
The well-aligned carbon nanotubes (CNTs) arrays with opened ends were prepared in ordered pores of anodic aluminum oxide (AAO) template by the chemical vapor deposition (CVD) method. After then, silicon nanowires (SiN...The well-aligned carbon nanotubes (CNTs) arrays with opened ends were prepared in ordered pores of anodic aluminum oxide (AAO) template by the chemical vapor deposition (CVD) method. After then, silicon nanowires (SiNWs) were deposited in the hollow cavities of CNTs. By using this method, CNTs/SiNWs core-sheath composite structure arrays were synthesized successfully. Growing structures and physical properties of the CNTs/SiNWs composite structure arrays were analyzed and researched by the scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectrum (XRD), respectively. The field emission (FE) behavior of the CNTs/SiNWs composite structure arrays was studied based on Fowler-Nordheim tunneling mechanism and current-voltage (/-V) curve. And the photoluminescence (PL) was also characterized. Significantly, the CNTs/SiNWs core-sheath composite structure nanowire fabricated by AAO template method is characteristic of a metal/semiconductor (M/S) behavior and can展开更多
Undoped and copper doped zinc oxide （ZnO） thin films have been prepared on glass substrates by spray pyrolysis technique. The films were doped with copper using the direct method by addition of a copper salt （CuCl2...Undoped and copper doped zinc oxide （ZnO） thin films have been prepared on glass substrates by spray pyrolysis technique. The films were doped with copper using the direct method by addition of a copper salt （CuCl2） in the spray solution of ZnO. Variation of structural, electrical, optical and thermoluminescence （TL） properties with doping concentrations is investigated in detail.展开更多
文摘Mg-doped ZnO radial spherical structures with nanorods grown on both sides of the spherical shell were successfully prepared via chemical vapor deposition （CVD） of Zn and Mg powders in the absence of a catalyst. The structures associated with different growth temperatures （700, 800, and 850°C） were monitored by scanning electron microscopy （SEM）, and the result shows that the length of the nanorods increase progressively with the growth temperature increasing. X-ray diffraction （XRD） shows that the as-obtained samples can be indexed to high crystallinity with wurtzite structure. The growth of the nanostructures mainly depends on the formation of sphere-like Mg-doped Zn droplets before adding oxygen. Photoluminescence （PL） spectra that show a 39 meV blue shift indicates that the band gap becomes large, because Mg substitutes Zn in the lattice.
基金Foundation items: National Natural Science Foundations of China (No.10835004,No.10775031)Science and Technology Commission of Shanghai Municipality,China (No. 10XD1400100)
文摘The hydrophobic films of TixOy-CmHn deposited from mixture gases of titanium isopropoxide (TTIP) and oxygen by plasma enhanced chemical vapor deposition (PECVD) were investigated. The films were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectrometer (FTIR), X-Ray diffraction (XRD), element analysis (EA), ultraviolet visible spectrometer (UV-Vis), and water contact angle (WCA). The results reveal that the surface of the films is formed by microsized papillaes aggregated by inorganic and organic phases of complex nanoparticles with size from 50 nm to 200 nm when the discharge power is increased from 40 W to 150 W. All films demonstrate the strong broad of Ti-O-Ti stretching vibration at 400-800 cm-1, -CH bending vibration at 1388 cm-1, and broadening -OH stretching vibration at 3000-3500 cm-1. With the increase of the discharge power, the as-deposited film changes from amorphous to crystallization. The WCA of the film can be as high as 160°, indicating the hydrophobicity. The films show a similar ultraviolet absorption property as the bulk TiO2 film. The composition of the composition of film deposited at 150 W can be formulated as Ti0.3O2-C1.5H3. Therefore, the composition formula of this hydrophobic film could be expressed as TiO2-C5H10O4.7. It is believed that the complex micro/nano structures of TiO2 and C5H10O4.7 residues are responsible for the observed hydrophobicity and the ultraviolet absorption property of the film.
基金The authors thank Mr. Cao Guixun of Analysis and Testing Center of Gansu Province Cor usefulhelp and discussion. This work was supported by the National Natural Science Foundation of China (Grant Nos. 69890220 and 69871013).
文摘The well-aligned carbon nanotubes (CNTs) arrays with opened ends were prepared in ordered pores of anodic aluminum oxide (AAO) template by the chemical vapor deposition (CVD) method. After then, silicon nanowires (SiNWs) were deposited in the hollow cavities of CNTs. By using this method, CNTs/SiNWs core-sheath composite structure arrays were synthesized successfully. Growing structures and physical properties of the CNTs/SiNWs composite structure arrays were analyzed and researched by the scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectrum (XRD), respectively. The field emission (FE) behavior of the CNTs/SiNWs composite structure arrays was studied based on Fowler-Nordheim tunneling mechanism and current-voltage (/-V) curve. And the photoluminescence (PL) was also characterized. Significantly, the CNTs/SiNWs core-sheath composite structure nanowire fabricated by AAO template method is characteristic of a metal/semiconductor (M/S) behavior and can
文摘Undoped and copper doped zinc oxide （ZnO） thin films have been prepared on glass substrates by spray pyrolysis technique. The films were doped with copper using the direct method by addition of a copper salt （CuCl2） in the spray solution of ZnO. Variation of structural, electrical, optical and thermoluminescence （TL） properties with doping concentrations is investigated in detail.
