Synthesis and Characterization of ZnO Nanowires Using a Simple PVD Approach without Catalysts

2005 ◽  
Vol 475-479 ◽  
pp. 3535-3538 ◽  
Author(s):  
Long Shan Wang ◽  
X. Zhang ◽  
Fan Hao Zeng

Two kinds of ZnO nanowires with different morphologies and characters were produced on Si (100) using a new PVD approach by heating and oxidizing Zn powders directly without any catalysts. The nanowires have an average diameter of 80nm (deposited at the evaporation source) and 30nm (deposited downstream of the evaporation source) respectively, and are evenly distributed over an area of > 20mm2. The two nanowires have complete different photoluminescence properties. One has a strong green emission (510nm) with a weak UV emission (380nm). The other has a strong and sharp UV emission (385nm), showing the capability for UV laser emitters.

2007 ◽  
Vol 7 (2) ◽  
pp. 486-489 ◽  
Author(s):  
Sathyaharish Jeedigunta ◽  
Manoj K. Singh ◽  
Ashok Kumar ◽  
M. Shamsuzzoha

High-density single-crystalline Zn2SnO4 nanowires have been successfully synthesized by using a simple thermal evaporation method by heating a mixture of ZnO and SnO2 nano powders. The products in general contain various geometries of wires, with an average diameter of 80–100 nm. These nanowires are ultra-long, up to 100 microns. The transmission electron microscopy study showed that these nanowires exhibited zigzag twinned geometry, and grow along the 〈111〉 direction. Low-temperature photoluminescence properties of the nanowires were measured, showing a strong green emission band at about 515 nm and a weak peak corresponding to UV emission at about 378 nm, which have not been reported before.


2013 ◽  
Vol 12 (04) ◽  
pp. 1350023 ◽  
Author(s):  
V. P. HEDAOO ◽  
V. B. BHATKAR ◽  
S. K. OMANWAR

Nanoscale phosphors have superior performance characteristics than the bulk phosphors. This paper explains the synthesis and characterization like XRD, FTIR, SEM and photoluminescence properties of nanocrystalline Sr 4 Al 14 O 25 doped with rare earth elements like europium, dysprosium and samarium by combustion method. XRD showed the nanoscale crystalline nature of as-prepared samples. SEM confirmed size of the particle less than 100 nm. Photoluminescent emission spectra showed strong orange red emission at 593 nm for Sr 4 Al 14 O 25: Sm 3+. The green emission of Eu 2+ was observed at around 490 nm for Sr 4 Al 14 O 25: Eu 2+.


Molecules ◽  
2012 ◽  
Vol 17 (5) ◽  
pp. 5021-5029 ◽  
Author(s):  
Mohammad Reza Khanlary ◽  
Vahid Vahedi ◽  
Ali Reyhani

2011 ◽  
Vol 239-242 ◽  
pp. 2851-2854 ◽  
Author(s):  
Jin Yu Yang ◽  
Yu Chang Su ◽  
Zhuo Chen ◽  
Xue Ying Liu

Phase-pure Eu3+doped Gd2Sn2O7nanocrystals have been successfully synthesized via a co-precipitation processes combined with hydrothermal treatment. The crystal structure, particle size, morphologies, composition, and photoluminescence properties of the as-synthesized products were investigated by XRD, SEM, TEM, EDS and PL. The samples were single-phase cubic pyrochlore-type nanocrystals with a typical size of about 30 - 60 nm. All the samples exhibited irregular flower like secondary nanostructure assembled by primary nanoparticles. Photoluminescence properties of Gd2Sn2O7:Eu3+were investigated, and the results revealed that the as-synthesized materials displayed intense and prevailing emission located at 580 - 630 nm. The excitation spectra indicated that an energy transfer from Gd3+to Eu3+occurred. Meanwhile, the concentration quenching phenomenon was observed in Gd2Sn2O7:Eu3+nanocrystals.


2019 ◽  
Vol 138 (6) ◽  
pp. 4463-4473 ◽  
Author(s):  
Renata Łyszczek ◽  
Beata Podkościelna ◽  
Agnieszka Lipke ◽  
Agnieszka Ostasz ◽  
Andrzej Puszka

Abstract The synthesis and characterization of luminescent hybrid composites based on bisphenol A glycerolate (1 glycerol/phenol) diacrylate (BPA-Acr) as a cross-linking monomer and N-vinylpyrrolidone (NVP) as an active diluent, in the presence of UV initiator (Irgacure 651), are presented. Eu(III) and Tb(III) carboxylate complexes were added as luminescent components of composites. In their preparation, a constant concentration of the initiator (1%) and the BPA-Acr to NVP (10:3) ratio were applied. The structures of the obtained materials were confirmed by the infrared spectra (ATR-FTIR). Thermal properties of the cross-linked products were determined by different thermal analysis methods in air and nitrogen (TG–DTG–DSC and TG–FTIR). Thermal stability, pathways of thermal decomposition and volatile products of degradation were determined. Photoluminescence properties of the lanthanide complexes and the obtained composites were established. These materials can have the potential application as coatings filtering harmful UV radiation.


2012 ◽  
Vol 568 ◽  
pp. 295-298
Author(s):  
Juan Liao ◽  
Kai Zhang ◽  
Wen Zhong Wang ◽  
Yong Gang Wang ◽  
Li Yu

AgCl microparticle materials, with novel heart-like morphology, were successfully prepared by means of a simple solution phase route, in which a small amount of hydrochloric acid, ethylene and PVP were introduced to the conventional polyol process. The obtained microparticle materials were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and UV-Vis absorption spectrum. SEM images show that the obtained AgCl microparticle materials have heart-like morphology with an average diameter of 3 um. The influence of different reaction times on size and morphology of the microparticle materials were also investigated. A possible growth mechanism of AgCl microparticle materials has been proposed on the basis of experimental results and analysis. The as-prepared AgCl microparticle materials would find possible potential applications in photocatalytic fields.


2009 ◽  
Vol 08 (03) ◽  
pp. 285-287 ◽  
Author(s):  
M. ESKANDARI ◽  
V. AHMADI ◽  
Sh. AHMADI

In this study, ZnO nanowires are synthesized via ZnO nanorods at low temperature by using zinc acetate dehydrate and polyvinylpyrrolidone as precursor and capping, respectively. We use chemical solution method for synthesis of ZnO nanowires. Samples are characterized by means of scanning electron microscopy and X-ray diffraction. First, the nanorods are prepared at 300°C temperature, and then they are put into the furnace under air atmosphere at 450°C for 2 h. It is observed that nanowires with 20 nm diameter are produced. Photoluminescence spectra of nanorods and nanowires are compared. It shows that intensity of ultraviolet peak in the nanowires decreases but in contrast the intensity of green emission part increases. This is because, the surface effects such as oxygen vacancies increase in the structures of ZnO .


2019 ◽  
Vol 15 ◽  
pp. 394-399
Author(s):  
Kanchana Shahi ◽  
RS Singh ◽  
Narendra P. Singh ◽  
Mariya Aleksandrova ◽  
Ajaya Kumar Singh

2008 ◽  
Vol 47-50 ◽  
pp. 642-645
Author(s):  
Yang Yen Yu ◽  
Wen Chen Chien ◽  
Chia Liang Tsai

The synthesis, morphology, and photophysical properties of Poly[2,7-(9,9-dihexyl fluorene)]- block-poly(2-(Dimethylamino) ethyl methacrylate) (PF-b-PDMAEMA) copolymers in various mixed solvents, i.e., THF/MeOH, DMF/MeOH, and 1,4-Dioxane/MeOH, with methanol contents of 0, 10, 25, 50, 75, 90 vol.% were reported. TEM images showed that different aggregate morphologies of PF-b-PDMAEMA, including spherical and large compound micelles, cylinder, nanorods, long stick-like structure, could be prepared by introducing different amount of methanol into the copolymer/solvent system. The results indicated that aggregate morphologies of PF-b-PDMAEMA, which obtained from various coil lengths and mixed solvents, had a great influenced on the optical and photoluminescence properties of the prepared PF-b-PDMAEMA copolymers.


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