Effects of interface bonding configuration on photoluminescence of ZnO quantum dots–SiOxNy nanocomposite films

2008 ◽  
Vol 23 (4) ◽  
pp. 1155-1162 ◽  
Author(s):  
Yu-Yun Peng ◽  
Tsung-Eong Hsieh ◽  
Chia-Hung Hsu
Keyword(s):  
Quantum Dots ◽  
Nanocomposite Films ◽  
Photoemission Spectroscopy ◽  
Yellow Emission ◽  
Interface Bonding ◽  
X Ray ◽  
Hole Trapping ◽  
Radio Frequency Sputtering ◽  
Surface Polarization ◽  
Zno Quantum Dots

Nanocomposite films containing ZnO quantum dots (QDs) and SiOxNy matrix were prepared by target-attached radio frequency sputtering. Photoluminescence (PL) dominated by violet and blue emissions was observed from all ZnO QD–SiOxNy nanocomposite films with dot diameters ranging from 2.77 to 6.65 nm. X-ray photoemission spectroscopy (XPS) revealed the formation of nitrogen-correlated bonding configurations in both the SiOxNy matrix and the dot/matrix interfaces. The nitrogen-correlated configuration at the interface produced a substantial polarization effect at dot surface. The suppression of green-yellow emission observed in photoluminescence spectra of all samples was ascribed to the hole-trapping process promoted by the enhancement of the surface polarization.

Transparent PMMA/ZnO nanocomposite films based on colloidal ZnO quantum dots

2007 ◽  
Vol 18 (21) ◽  
pp. 215606 ◽  
Author(s):  
Dazhi Sun ◽  
Nobuo Miyatake ◽  
Hung-Jue Sue
Keyword(s):  
Quantum Dots ◽  
Nanocomposite Films ◽  
Zno Quantum Dots

scholarly journals Hydrothermal synthesis of ZnO quantum dot/KNb3O8 nanosheet photocatalysts for reducing carbon dioxide to methanol

2017 ◽  
Vol 8 ◽  
pp. 2264-2270 ◽  
Author(s):  
Xiao Shao ◽  
Weiyue Xin ◽  
Xiaohong Yin
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Uv Light ◽  
Formation Rate ◽  
X Ray Diffraction ◽  
Methanol Production ◽  
X Ray ◽  
Transmission Electron ◽  
Methanol Formation ◽  
Zno Quantum Dots

ZnO quantum dots and KNb3O8 nanosheets were synthesized by a two-step hydrothermal method for the photocatalytic reduction of CO2 to methanol where isopropanol is simultaneously oxidized to acetone . The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and UV–vis absorption spectroscopy (UV–vis). The photocatalytic activity of the materials was evaluated by formation rate of methanol under UV light irradiation at ambient temperature and pressure. The methanol formation rate of pure KNb3O8 nanosheets was found to be 1257.21 μmol/g/h, and after deposition of 2 wt % ZnO quantum dots on the surface of KNb3O8 nanosheets, the methanol production rate was found to increase to 1539.77 μmol/g/h. Thus, the ZnO quantum dots obviously prompted separation of charge carriers, which was explained by a proposed mechanism for this photocatalytic reaction.

Surfactant-free Colloidal Crystal of ZnO Quantum Dots

2009 ◽  
Vol 1207 ◽  
Author(s):  
Xi Zhang ◽  
Dazhi Sun ◽  
Hung-Jue Sue
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Colloidal Crystal ◽  
Uv Light ◽  
X Ray ◽  
Transmission Electron ◽  
Close Packed Structure ◽  
Packed Structure ◽  
Zno Quantum Dots ◽  
Zno Qds

AbstractMonodisperse ZnO quantum dots (QDs) with a particle size of about 5 nm have been synthesized. Isopropanol together with hexane were utilized to precipitate ZnO nanoparticles to form condensed phases, ranging from white flocculation, to gel-like fluid, and to transparent solid. The morphology and structure in the transparent ZnO solid was characterized by UV-vis, X-ray diffraction, small-angle X-ray scattering, transmission electron microscopy, and scanning electron microscopy. The mechanisms for the formation of transparent ZnO QDs close-packed structure were monitored via UV-vis spectra, and found likely to be a colloidal crystal. The colloidal crystal is transparent and absorbs UV light efficiently. Possible conditions for the formation of the ZnO QDs colloidal crystal are discussed.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

X-ray spectroscopic diagnostics of the structure of quantum dots based on zinc and manganese sulfides and oxides

2017 ◽  
Vol 58 (8) ◽  
pp. 1683-1690
Author(s):  
I. A. Pankin ◽  
◽  
A. N. Kravtsova ◽  
O. E. Polozhentsev ◽  
A. P. Budnyk ◽  
...  
Keyword(s):  
Quantum Dots ◽  
X Ray ◽  
Spectroscopic Diagnostics

Electronic Study of Pt-Ga Intermetallic Compounds Using X-Ray Photoemission Spectroscopy

1990 ◽  
Author(s):  
Young K. Kim ◽  
David K. Shuh ◽  
R. S. Williams ◽  
Larry P. Sadwick ◽  
Kang L. Wang
Keyword(s):  
Intermetallic Compounds ◽  
Photoemission Spectroscopy ◽  
X Ray

Nanocomposite synthesis by thermolysis of [Ag(hfac)(COD)] in amorphous polystyrene

2012 ◽  
Vol 19 (2) ◽  
pp. 195-197 ◽  
Author(s):  
Gianfranco Carotenuto ◽  
Mariano Palomba ◽  
Luigi Nicolais
Keyword(s):  
Polymer Matrix ◽  
Nanocomposite Films ◽  
Numerical Density ◽  
Silver Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Yellow Coloration ◽  
Color Filters ◽  
Silver Atoms

AbstractLightfast color filters (intensively and brightly colored) can be easily produced by dying optical plastics with the surface plasmon resonance (SPR) of metal nanoparticles such as silver and gold. Here, color filters based on silver nanoparticles embedded in amorphous polystyrene have been prepared by dissolving and thermally decomposing (1,5-cyclooctadiene)(hexafluoro-acetylacetonate)silver(I) in amorphous polystyrene. The metal precursor quickly decomposes (10 s, at 180°C), leading to silver atoms that clusterize and produce a non-aggregated dispersion of silver particles in the polymer matrix. The intensity of the yellow coloration due to the SPR of nanoscopic silver can be widely tuned simply by varying the cluster numerical density in the polymer matrix that depends on the silver precursor concentration. The obtained nanocomposite films have been characterized by X-ray power diffraction, transmission electron microscopy, and UV-Vis spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document