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1.
For the first time, aligned ZnO nanorod structured thin films have been synthesized on a glass substrate, which had been coated with an Al-doped ZnO thin film, using the sonicated sol-gel immersion method. These nanorods were found to have an average diameter of 100 nm and an average length of 500 nm, with hexagonal wurtzite phase grew preferentially along the c-axis direction. A sharp ultra-violet (UV) emission centred at 383 nm corresponding to the free exciton recombination was observed in a room temperature photoluminescence (PL) spectrum. The prepared ZnO nanorod structured thin film is transparent in the visible region with an average transmittance of 78% in the 400-800 nm wavelength range and high absorbance properties in the UV region (< 400 nm). The results indicate that the prepared ZnO nanorods are suitable for ultra-violet photoconductive sensor applications. 相似文献
2.
Mrinmoy Misra Pawan Kapur Madan Lal Singla 《Journal of Materials Science: Materials in Electronics》2013,24(10):3940-3945
In this study ZnO nanorods have been synthesized by a chemical precipitation method. The room temperature UV–Vis absorption spectra of the ZnO nanorods indicated two absorption peaks in the UV region, one in the near UV region and the other attributed to the band gap of ZnO. The Photoluminescence spectra of ZnO nanorods show two emission bands, one ultraviolet emission band at 378 nm and the other in the defect related yellow emission band near 550 nm. The stimulated yellow luminescence of ZnO nanorods were affected by the synthesis time and annealing temperature. The same ZnO nanorods were deposited onto the ITO substrate to form a UV photoconductive detector. The ratio of the UV photogenerated current to dark current was as high as nine times under 3 V bias. Hence, these nanorods can be promising materials in the use of UV radiation detection. 相似文献
3.
Products consisted of Al-doped ZnO nanodisks and ZnO nanorod clusters were synthesized by chemical co-deposition process. The nanodisks with large polar surface are about 1–2 µm in diameter and 20 nm in thickness. The ZnO nanorods have an average diameter of 40 nm. The content of ZnO nanodisks can be adjusted by Al3+ content. The growth mechanism of the ZnO nanodisks is also discussed. Room temperature photoluminescence (PL) measurements show that photoluminescence peaks of the products decrease with the increase of Al content. 相似文献
4.
Reza Shabannia 《Journal of Materials Science: Materials in Electronics》2018,29(14):11646-11652
Vertical well-aligned Cu-doped ZnO nanorods were successfully synthesized by chemical bath deposition (CBD) method on low cost and flexible polyethylene naphthalate (PEN) substrate. The structural and optical investigations exhibited the high quality of the Cu-doped ZnO nanorods on a flexible PEN substrate. The metal-semiconductor-metal (MSM) configuration was used to fabricate UV photodetector based on the Cu-doped ZnO nanorods grown on PEN substrate. Under a 5 V applied bias, the values of dark current and photocurrent of the Cu-doped ZnO nanorods photodetector were 14.9 µA and 3.27 mA, respectively. Meanwhile, calculated photocurrent gain of the UV photodetector was 219 at 5 V bias voltage. Upon exposure to 365 nm UV light, the UV device exhibited fast response time and recovery time of 0.317 and 0.212 s, respectively, at a bias voltage of 5 V. 相似文献
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Mrinmoy Misra Pawan Kapur C. Ghanshyam Madan Lal Singla 《Journal of Materials Science: Materials in Electronics》2013,24(10):3800-3804
In the present study photoluminescence behavior of ZnO and ZnO@CdS core–shell nanorods film has been reported. ZnO nanorods were grown on the glass coated indium tin oxide (ITO) surface by seeding ZnO particle followed with nanorods growth. These nanorods were coated with CdS by chemical bath deposition techniques to have ZnO@CdS thin film and further annealed at 200 °C for their adherence to the ITO surface. The coating was characterized for surface morphology using SEM and optical behavior using UV–visible spectrophotometer. Energy dispersive X-ray (EDX) was used for compositional analysis and time resolve photoluminescence decay for excitons life time measurement. The absorption spectrum reveals that the absorption edge of ZnO@CdS core–shell heterostructure shifted to 480 nm in the visible region whereas ZnO nanorods have absorption maxima at 360 nm. The excitons lifetime of ZnO@CdS was found to be increased with the thickness of the CdS layer on ZnO nanorod. These ZnO@CdS core–shell nanostructures will be of great use in the field of photovoltaic cell and photocatalysis in a UV–visible region. 相似文献
7.
S. B. Babar N. L. Gavade J. Park K. M. Garadkar V. M. Bhuse 《Journal of Materials Science: Materials in Electronics》2017,28(12):8372-8381
In the present work, we have demonstrated a simple, facile, one-step, rapid and cost effective synthesis of ZnO nanorods through the thermal decomposition of zinc acetate and leavening agent (NaHCO3). The silver nanoparticles (AgNPs) were deposited on the surface of ZnO nanorods by photocatalytic reduction of Ag (I) to Ag(0). As synthesized ZnO nanorods and Ag–ZnO nanocomposites were characterized by using X-ray Diffraction, field emission scanning electron microscope, high-resolution transmission electron microscope and diffuse reflectance spectroscopy. The photocatalytic activities of the ZnO nanorods and Ag–ZnO nanocomposites were evaluated for the photodegradation of Methyl Orange (MO) under UV and sunlight irradiation. The use of common leavening agent helps to prevent the aggregation of ZnO nanorods, further it hinders crystallite growth and narrowing the diameter of nanorods by the evolution of carbon dioxide during calcination. The ZnO nanorods and Ag–ZnO nanocomposite exhibited an enhanced photocatalytic activity and separation of photogenerated electron and hole pairs. Due to effect of leavening agent and AgNPs deposited on surface of ZnO nanorods finds best catalyst for the 99% degradation of MO within 30 min compared to ZnO. 相似文献
8.
《Materials Letters》2005,59(14-15):1745-1747
ZnO nanorods and trigonal-shaped ZnO ultrafine particles were synthesized by sonochemical method through the decomposition of zinc acetate dihydrate in paraffin oil. ZnO nanorods and trigonal-shaped ZnO ultrafine particles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), and UV–visible spectrophotometer. One strong UV emission peak at 390 nm was observed. 相似文献
9.
Ma S Fang G Li C Sheng S Fang L Fu Q Zhao XZ 《Journal of nanoscience and nanotechnology》2006,6(7):2062-2066
High-density well-aligned ZnO nanorod array was successfully synthesized on a large-area magnetron sputtering deposited Al doped ZnO film-coated Si (AZO/Si) substrate via a convenient solution method. X-ray diffraction and scanning electron microscopy show that the nanorods are well-oriented perpendicular to the substrate. The influences of the reaction temperature, time, on the size and shapes of the as-prepared ZnO nanorods (ZNs) samples have been studied. The length and diameter of the nanorods became bigger when a longer reaction time was used. When the temperature is elevated to 130 degrees C, a new conical ZNs was synthesized. Room-temperature photoluminescence (PL) spectra of all the ZnO products showed a strong ultraviolet (UV) emission. The photoluminescence from free excitons of the ZNs synthesized at higher temperature reflects the high purity and nearly defect free structure of nanorods. The well-aligned feature of the nanorod array is attributed to the nanorods' epitaxial growth from the AZO films. 相似文献
10.
J. Prince Richard I. Kartharinal Punithavathy S. Johnson Jeyakumar M. Jothibas P. Praveen 《Journal of Materials Science: Materials in Electronics》2017,28(5):4025-4034
In the present work, high purity ZnO nanorods were synthesized by solid state reaction method at different annealing temperatures (250–400 °C). The structural, morphological and optical characteristic of the ZnO nanorods were studied. X-ray diffraction results confirmed that the ZnO nanorods have Wurtzite structure with high crystal quality. The grain size has increased from 23 to 27 nm with increasing temperature. The scanning electron microscopy and high resolution-transmission electron microscopy photographs showed the formation of ZnO nanorods. The bonding natures of the synthesized nanorods were analyzed by Fourier transform infra-red spectroscopy. The blue shift in the absorption edge was observed from the UV–Vis spectrum. The photoluminescence spectra showed two emission peaks corresponding to blue and red emissions. The photocatalytic performance of these nanorods was evaluated using methyl violet dye. The result showed that photocatalytic performance is highly depends on the morphology of the nanorods. 相似文献
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Nanostructured ZnO (nanorods, nanoshuttles) have been synthesized by hydrothermal approach using ZnCl2 or Zn(NO3)2·6H2O as zinc sources and cetyltrimethylammonium bromide as structure-directing agent. Techniques X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible absorption, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy have been used to characterize the structure, morphology and composition of the nanostructured zinc oxide. The optical properties of the as-obtained materials were also studied and showing that it is possible to apply the ZnO nanoshuttles and nanorods on the UV filter, photocatalysis, and special optical devices. 相似文献
13.
Zeyan Wang Baibiao Huang Xiaojing Liu Xiaoyan Qin Xiaoyang Zhang Jiyong Wei Peng Wang Shushan Yao Qi Zhang Xiangyang Jing 《Materials Letters》2008,62(17-18):2637-2639
Well-aligned ZnO nanorod arrays have been synthesized by a simple hydrothermal method with polyvinyl alcohol as surfactant on F:SnO2 conductive glasses substrates. Visible violet photoluminescence has been observed at room temperature. A series of annealing treatments in different environments have been made in order to investigate the nature of these emissions. The violet emission shows no change after annealing in air, while shifts to the ultra-violet region after annealing in H2. It is concluded that the violet emission is due to VZn− defect formed at the surface of the ZnO nanorods. 相似文献
14.
Without using additional surfactant as structure-directing agent, well dispersed ZnO nanorods were directly synthesized in the dimethyl sulfoxide (DMSO) and alcohol mixture solution by a one-step wet chemical method. The experiment results demonstrated that alcohol molecular with longer chain is helpful for the growth of ZnO nanorods. The absorption and emission spectra of as-synthesized ZnO nanorods were also presented in this paper. 相似文献
15.
PRITAM PATIL GANESH GAIKWAD D R PATIL JITENDRA NAIK 《Bulletin of Materials Science》2016,39(3):655-665
1-D ZnO nanorods and PPy/1-D ZnO nanocomposites were prepared by the surfactant-assisted precipitation and in situ polymerization method, respectively. The synthesized nanorods and nanocomposites were characterized by UV–Vis spectrophotometer, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM), which gave the evidence of 1-D ZnO nanorods, polymerization of pyrrole monomer and strong interaction between PPy and 1-D ZnO nanorods, respectively. Photocatalytic activity of 1-D ZnO nanorods was conducted by 33 level full-factorial design to evaluate the effect of three independent process variables viz., dye concentration (crystal violet), catalyst concentration (1-D ZnO nanorods) and the reaction time on the preferred response: photodegradation efficiency (%). The PPy/1-D ZnO nanocomposites were used for the sensing of NH3, LPG, CO2 and H2S gases, respectively, at room temperature. It was observed that PPy/1-D ZnO nanocomposites with different 1-D ZnO nanorod weight ratios (15 and 25%) had better selectivity and sensitivity towards NH3 at room temperature. 相似文献
16.
Meenu Makkar H. S. Bhatti Karamjit Singh 《Journal of Materials Science: Materials in Electronics》2014,25(11):4822-4829
We report a simple hydrothermal method at low temperature for synthesis of zinc oxide (ZnO) nanorods followed by ultrasonication. The samples were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), UV–Vis absorption spectrophotometer and photoluminescence (PL) spectroscopy. The XRD results shows the prepared ZnO nanocrystals are in wurtzite structure. TEM results indicate the growth of ZnO nanorods with increasing reaction stirring time and morphology also get affected after ultrasonication. PL studies also reveal the presence of defects considered as the main reason for the green emission in PL with increasing reaction time and blue shift in UV emission corresponds to reduction of tensile strain. 相似文献
17.
Dielectrophoretic fabrication and characterization of a ZnO nanowire-based UV photosensor 总被引:2,自引:0,他引:2
Suehiro J Nakagawa N Hidaka S Ueda M Imasaka K Higashihata M Okada T Hara M 《Nanotechnology》2006,17(10):2567-2573
Wide-gap semiconductors with nanostructures such as nanoparticles, nanorods, nanowires are promising as a new type of UV photosensor. Recently, ZnO (zinc oxide) nanowires have been extensively investigated for electronic and optoelectronic device applications. ZnO nanowires are expected to have good UV response due to their large surface area to volume ratio, and they might enhance the performance of UV photosensors. In this paper, a new fabrication method of a UV photosensor based on ZnO nanowires using dielectrophoresis is demonstrated. Dielectrophoresis (DEP) is the electrokinetic motion of dielectrically polarized materials in non-uniform electric fields. ZnO nanowires, which were synthesized by nanoparticle-assisted pulsed-laser deposition (NAPLD) and suspended in ethanol, were trapped in the microelectrode gap where the electric field became higher. The trapped ZnO nanowires were aligned along the electric field line and bridged the electrode gap. Under UV irradiation, the conductance of the DEP-trapped ZnO nanowires exponentially increased with a time constant of a few minutes. The slow UV response of ZnO nanowires was similar to that observed with ZnO thin films and might be attributed to adsorption and photodesorption of ambient gas molecules such as O(2) or H(2)O. At higher UV intensity, the conductance response became larger. The DEP-fabricated ZnO nanowire UV photosensor could detect UV light down to 10?nW?cm(-2) intensity, indicating a higher UV sensitivity than ZnO thin films or ZnO nanowires assembled by other methods. 相似文献
18.
《Vacuum》2013
Herein one-dimensional Sm-doped ZnO nanostructures have been successfully fabricated by a simple hydrothermal method at a low temperature of 90 °C. The effect of Sm doping on the microstructure, photoluminescence and magnetism of ZnO nanorods is also investigated. FE-SEM images show that the average diameter of the Sm-doped ZnO nanorods is obviously smaller than that of ZnO nanorods. Photoluminescence spectrum of Sm-doped ZnO nanorods shows a slightly red-shifted decrease of UV emission and an enhancement of photoluminescence performance of visible emission. Raman spectrum of Sm-doped ZnO nanorods reveals that the peak intensity corresponding to the E2 high mode decreases significantly compared with that of the pure ZnO nanorods, indicating the restraint of crystallization. Room temperature ferromagnetism is observed from magnetization curves of both ZnO and Sm-doped ZnO nanorods. The increase of the saturation magnetization induced by the Sm doping in the ZnO nanorods reveals an association with the increase of oxygen vacancies and oxygen interstitials. 相似文献
19.
M. Thambidurai N. Muthukumarasamy Dhayalan Velauthapillai Changhee Lee 《Journal of Materials Science: Materials in Electronics》2013,24(6):1921-1926
ZnO nanorods using various molar concentrations have been synthesized through the chemical bath deposition method. X-ray diffraction result shows that the ZnO nanorods are of hexagonal structure. The morphology of the ZnO nanorods has been examined by scanning electron microscopy. The ZnO nanorods have diameters ranging from 100 to 200 nm and length of 1–3 μm. Dye-sensitized solar cells have been assembled by using ZnO nanorod film photoelectrode sensitized using natural dye extracted from lantana camara as sensitizer. The ZnO nanorods have been used as electrode material to fabricate dye sensitized solar cells which exhibited an efficiency of 0.71 %, the maximum efficiency was obtained for films deposited for 0.07 M concentration. 相似文献
20.
Ha SY Jung MN Park SH Ko HJ Ko H Oh DC Yao T Chang JH 《Journal of nanoscience and nanotechnology》2006,6(11):3624-3627
Well-aligned ZnO nanorods have been achieved using new alloy (AuGe) catalyst. Zn powder was used as a source material and it was transported in a horizontal tube furnace onto an AuGe deposited Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, high resolution X-ray diffraction, and photoluminescence. ZnO nanorods grown at 650 degrees C on 53 nm thick AuGe layer show uniform shape with the length of 8 +/- 0.5 microm and the diameter of 150 +/- 5 nm. Also, the tilting angle of ZnO nanorods (+/- 5.5 degrees) is confirmed by HRXRD. High structural quality of the nanorods is conformed by the photoluminescence measurement. All samples show strong UV emission without considerable deep level emission. However, weak deep level emission appears at high (700 degrees C) temperature due to the increase of oxygen desertion. 相似文献