Thickness effect of sputtered ZnO seed layer on the fabrication of ZnO nanorods on flexible polyimide films and their ethanol gas sensing properties

2011 ◽  
Vol 1303 ◽  
Author(s):  
Hosang Ahn ◽  
Seon-Bae Kim ◽  
Dong-Joo Kim
Keyword(s):  
Seed Layer ◽  
Flexible Substrate ◽  
Zno Nanorods ◽  
Debye Length ◽  
Morphological Characteristics ◽  
Gas Absorption ◽  
Thickness Effect ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
Seed Layers

ABSTRACTControlled ZnO nanostructures were grown on a flexible substrate for the future development of smart sensing tags. Thermolysis-assisted chemical solution deposition was used to grow ZnO nanorods at 85°C from 0.01mol of Zinc nitrate hexahydrate and HMT (Hexamethyltetramine) solution. To promote and modulate the ZnO nanorods, R.F. sputtered ZnO seed layers were deposited on polyimide substrates at various film thicknesses in the range of 8 to 160 nm. The optimum processing conditions to fabricate ZnO nanostructures have been investigated to examine the growth behaviors and to correlate the process parameters with the morphological characteristics. When the ethanol gas sensitivities were measured at different thickness of ZnO seed layers before growing ZnO nanorods, the highest sensitivity was obtained at 40 nm thick ZnO film at 300°C where the film thickness is similar to the Debye length. When ZnO nanorods were grown on such a ZnO seed layer, the sensitivities were more heavily influenced by the ZnO nanostructures rather than the thickness of the seed layer probably due to the dominant proportion of carrier density involved with the gas absorption.

Effect of ZnO Seed Layer with Various Concentrations of Precursor on the Growth of ZnO Nanostructures

2016 ◽  
Vol 675-676 ◽  
pp. 237-240
Author(s):  
Nontakoch Siriphongsapak ◽  
Somyod Denchicharoen ◽  
Pichet Limsuwan
Keyword(s):  
Zinc Acetate ◽  
Seed Layer ◽  
Zinc Acetate Dihydrate ◽  
Zno Nanorods ◽  
Crystallographic Structure ◽  
Nitrate Hexahydrate ◽  
X Rays ◽  
Zno Nanostructures ◽  
Acetate Dihydrate ◽  
Seed Layers

In this work, Zinc oxide (ZnO) thin films were deposited on silicon and glass substrates using spin-coating method with different concentrations of precursor (zinc acetate dihydrate) and stabilizer (monoethanolamine). The concentrations of zinc acetate dihydrate and monoethanolamine in isopropanol were varied from 6 mM to 500 mM. Subsequently, the substrate with ZnO thin film as a seed layer was used to grow ZnO nanostructures by hydrothermal process with the same concentration of precursor (zinc nitrate hexahydrate), temperature, and time for each growth. The samples were characterized by field-emission scanning electron microscopy (FESEM), X-rays diffractometer (XRD), and UV-visible spectrophotometer (UV-vis) to study morphology, crystallographic structure, and optical property, respectively. The results showed that particle size, crystallinity, and transmittance of seed layers were changed with increasing concentrations of spin-coated precursor. Furthermore, the nanostructures were found that higher precursor concentration of seed layers affected the formation of ZnO nanorods to be nanosheets.

Influence of Al, Ta Doped ZnO Seed Layer on the Structure, Morphology and Optical Properties of ZnO Nanorods

2019 ◽  
Vol 4 (1) ◽  
pp. 45-58
Author(s):  
S. Mageswari ◽  
Balan Palanivel
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Band Gap ◽  
Seed Layer ◽  
Hexagonal Phase ◽  
Zno Nanorods ◽  
Oxide Material ◽  
Vertically Aligned ◽  
Doped Zno ◽  
Seed Layers

Background: Zinc oxide (ZnO) is one of the most attractive II-VI semiconductor oxide material, because of its direct wide band gap (3.37 eV) and large binding energy (60 meV). Zinc oxide (ZnO) is a promising semiconductor due to its optimised optical properties. Among semiconductor nanostructures, the vertically aligned one-dimensional ZnO nanorods are very important for nano device application. Methods: Vertically aligned ZnO nanorod arrays were grown on ZnO, aluminum doped ZnO (ZnO:Al), tantalum doped ZnO (ZnO:Ta) and aluminum and tantalum co-doped ZnO (ZnO:Al,Ta) seed layer by hydrothermal method. Results: The X-Ray Diffraction (XRD) investigation indicated the presence of hexagonal phase for the both seed layers and nanorods. The Scanning Electron Microscope (SEM) images of ZnO and doped ZnO seed layer thin-films show spherical shaped nanograins organized into wave like morphology. The optical absorption spectra revealed shift in absorption edge towards the shorter wavelength (blue shifted) for ZnO nanorods grown on ZnO:Al, ZnO:Ta and ZnO:Al,Ta seed layer compared to ZnO nanorods grown on ZnO seed layer. Conclusion: The increase in band gap value for the ZnO nanorods grown on doped ZnO seed layers due to the decrease in crystallite size and lattice constant as evidenced from XRD analysis. The unique property of Al, Ta doped ZnO can be used to fabricate nano-optoelectronic devices and photovoltaic devices, due to their improved optical properties.

ZnO Nanostructures – Nanorods and Flower-Like on Si/Au Substrates by Solution-Immersion Method in Different pH of Precursor

2013 ◽  
Vol 667 ◽  
pp. 86-92 ◽  
Author(s):  
Zuraida Khusaimi ◽  
Mohamad Hafiz Mamat ◽  
Norbani Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Zno Nanorods ◽  
Emission Spectra ◽  
Precursor Solution ◽  
Considerable Effect ◽  
Zinc Nitrate ◽  
Visible Emission ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
Immersion Method ◽  
Solution Ph

Low-temperature solution immersion growth of low-dimensional ZnO nanostructures on gold-seeded Si substrate has been demonstrated. pH environment of the precursor solution, Zn(NO3)2.6H2O (zinc nitrate hexahydrate) and C6H12N4 (HMTA) was found to have considerable effect to ZnO morphology and photoluminescence. Structural, morphological and photoluminescence (PL) properties of the samples were obtained from XRD, SEM and PL-Raman characterisation. A near neutral (pH = 6.8) and acidic (pH = 5) precursor solution aided a dense near-aligned ZnO nanorods growth with smallest rods diameter of 30 and 20 nm respectively. Whereas alkaline precursor solution (pH = 9) gave rise to flower-like structures of ZnO. Chemical equations for the reactions and the role of H+ and OH- ions role in affecting the XRD diffraction peaks and morphology, are suggested. Room temperature PL emission spectra of ZnO were collected after excitation at 325 nm. UV and visible emission distinctive of ZnO were formed and the rationale for significant shifts of the visible emission was also discussed.

Hydrothermal Growth of ZnO Nanorods along the Ultra-Thin ZnO Seed Layer Prepared by Magnetron Sputtering

2016 ◽  
Vol 675-676 ◽  
pp. 130-133
Author(s):  
Wissawat Sakulsaknimitr ◽  
Kanyakorn Teanchai ◽  
Mati Horprathum ◽  
Chanunthorn Chananonnawathorn ◽  
Saksorn Limwichean ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Seed Layer ◽  
Treatment Process ◽  
Zno Nanorods ◽  
Annealing Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Seed Layers

ZnO nanorods were grown on magnetron sputtered ultra-thin ZnO seed layers through a hydrothermal method. Before ZnO nanorods growth, the ultra-thin ZnO seed layer has been annealed at temperatures ranging from 100 to 400°C in air. The influence of annealing treatment on the crystalline structure of the ultra-thin ZnO seed layers has been investigated by X-ray diffraction (XRD). The size and density of final prepared ZnO nanorods were investigated by field-emission scanning electron microscopy (FE-SEM). It was found that the length and the aspect ratio of the ZnOnanorods can be readily tuned by control of the ZnO ultra-thin seeds layer which results from the annealing treatment process.

Effect of ZnO Seed Layer and TiO2 Coating Treatments on Aligned TiO2/ZnO Nanostructures for Dye-Sensitized Solar Cells

2013 ◽  
Vol 479-480 ◽  
pp. 69-74
Author(s):  
Lung Chuan Chen ◽  
Jean Hong Chen ◽  
Shuei Feng Tsai ◽  
Guan Wen Wang
Keyword(s):  
Solar Cells ◽  
Seed Layer ◽  
Zno Nanorods ◽  
Dye Sensitized Solar Cells ◽  
Atomic Ratio ◽  
Band Gap Energy ◽  
Zno Nanostructures ◽  
Dye Sensitized ◽  
Cbd Method ◽  
Sensitized Solar Cells

A chemical bath deposition (CBD) method was applied to grow zinc oxide nanorod arrays on transparent conductive oxides acting as templates for the synthesis of TiO2/ZnO nanostructures (TiO2/ZNR) followed by HCl etching, and then these nanostructures were assembled as anodes in dye-sensitized solar cells. The ZnO nanorods, predominantly grew with good crystallinity along c-axis, exhibit wurtzite structure with smooth surface. Etching of the TiO2/ZNR by HCl changes the most preferential crystal plane of ZnO from (002) to (100) and significantly increases the atomic ratio of Ti/Zn. Optical absorption measurements indicate a band gap energy of 3.1 eV for ZNR and TiO2/ZNR. Increasing the spin coating time (SCT) of TiO2on ZNR increases the PL intensity. The seed layer number (SLN) of ZnO exerts moderate influence on the photo-to-electricity conversion and an optimum SLN was observed for this study.

ZnO NANORODS GROWN ON PLASTIC PVC SUBSTRATE FOR ENVIRONMENTAL APPLICATION

2020 ◽  
pp. 149-153
Author(s):  
Hanh
Keyword(s):  
Methylene Blue ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Seed Layer ◽  
Zno Nanorods ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Nitrate Hexahydrate ◽  
Environmental Application ◽  
Scanning Electron

In this work, the hydrothermal growth of ZnO nanorods (NRs) on plastic PVC substrate is presented. It was shown that ZnO NRs with high density and high crystallinity can be successfully grown by implementing saturated nutrition solution of zinc nitrate hexahydrate (Zn[NO3]2·6H2O) and hexamethylenetetramine (C6H12N4) without the assistance of a seed layer. The morphologies of the ZnO nanorods investigated by scanning electron microscope (SEM) demonstrated hexagonal structures. The crystallinity of the ZnO NRs was studied by photoluminescence (PL) spectroscopy. The as-grown ZnO NRs were then utilized for photocatalytic degradation of methylene blue.

scholarly journals Synthesis and Characterization of c-Axis Oriented Zinc Oxide Thin Film and Its Use for the Subsequent Hydrothermal Growth of Zinc Oxide Nanorods

MRS Advances ◽  
2019 ◽  
Vol 4 (16) ◽  
pp. 921-928
Author(s):  
S.F.U. Farhad ◽  
N.I. Tanvir ◽  
M.S. Bashar ◽  
M. Sultana
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Seed Layer ◽  
Optical Band Gap ◽  
Zno Nanorods ◽  
Zinc Oxide Nanorods ◽  
Oxide Thin Film ◽  
Yellow Emission ◽  
Zno Films ◽  
Seed Layers

ABSTRACTOriented ZnO seed layers were deposited by three different techniques, namely, simple drop casting (DC), sol-gel derived dip coating (DPC) and spin coating of ball-milled ZnO powder solution(BMD) for the subsequent growth of vertically aligned ZnO nanorods along the substrate normal. X-ray diffraction (XRD) analyses revealed that ZnO(DC) seed layer exhibit the highest preferential c-axis texturing among the ZnO seed layers synthesized by different techniques. The Scanning Electron Microscopy (SEM) analysis evident that the morphology of ZnO seed layer surface is compact and coherently carpets the underlying substrate. ZnO nanorods(NRs) were then grown by hydrothermal method atop the ZnO seeded and non-seeded substrates grown by different techniques to elucidate the best ZnO seed layer promoting well-aligned ZnO Nanorods. The presence of c-axis oriented ZnO(DC) seeding layers was found to significantly affect the surface morphology and crystallographic orientation of the resultant ZnO NRs films. The optical band gap of ZnO(DC) seed and ZnO NRs were estimated to be 3.30 eV and in the range of 3.18 – 3.25 eV respectively by using UV-VIS-NIR diffuse reflection spectroscopy. The room temperature photoluminescence analyses revealed that nanostructured ZnO films exhibit a sharp near-band-edge luminescence peak at ∼380 nm consistent with the estimated optical band gap and the ZnO nanorod arrays are notably free from defect-related green-yellow emission peaks.

Feasibility of ZnO and Zn Seed Layers for Growth of Vertically Aligned and High-Quality ZnO Nanorods by the Sonochemical Method

2019 ◽  
Vol 290 ◽  
pp. 267-273
Author(s):  
Nama A. Hammed ◽  
Azlan Abdul Aziz ◽  
Adamu Ibrahim Usman
Keyword(s):  
Electron Microscopy ◽  
Seed Layer ◽  
Zno Nanorods ◽  
Volume Ratio ◽  
Sonochemical Method ◽  
Adhesion Layer ◽  
High Quality ◽  
X Ray ◽  
Vertically Aligned ◽  
Seed Layers

The role of both zinc oxide (ZnO) and zinc (Zn) seed layers were evaluated for the growth of vertically aligned high-quality zinc oxide (ZnO) nanorods by the sonochemical method. A total of four samples categorized into two groups were evaluated, with a different type and thickness of seed layer for the first group - ZnO, 85 nm and the second group - Zn, 55 nm respectively. This was after depositing Ti (10 nm) as the adhesion layer on p-type Si (111) substrates for two samples, and without the adhesion layer on the others. All depositions were carried out using RF-sputtering. The effects of the seed layers on the growth of vertically aligned high-quality ZnO nanorods were systematically studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). Results show that the type and thickness of a seed layer are key parameters to the synthesis of high quality ZnO nanorods. Results also show that the Ti (10 nm) adhesion layer did not affect the growth surface-to-volume ratio of the ZnO nanorods and the ZnO nanorods synthesized using ZnO (85 nm) as seed layer has a better surface-to-volume ratio compared to that using Zn (55 nm) as seed layer, with and without the adhesion layer.

Growth of ZnO Nanostructures at Different Reactant Concentrations for Inverted Organic Solar Cell

2012 ◽  
Vol 545 ◽  
pp. 71-75
Author(s):  
Chi Chin Yap ◽  
Ainu Abu Bakar ◽  
Muhammad Yahaya ◽  
Muhamad Mat Salleh
Keyword(s):  
Solar Cell ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Zno Nanorods ◽  
Acid Methyl Ester ◽  
Open Circuit ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
Reactant Concentration

The effects of reactant concentration on the growth of ZnO nanostructures and the photovoltaic performance of inverted organic solar cells based on a blend of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) as donor and (6,6)-phenyl-C61 butyric acid methyl ester (PCBM) as acceptor with a structure of FTO/ZnO nanostructures/MEHPPV:PCBM/Ag utilizing ZnO nanostructures as electron collecting layer and silver as a hole collecting electrode were investigated. The ZnO preparation consisted of ZnO nanoparticles seed layer coating and followed by ZnO nanostructures growth in equimolar aqueous solution of zinc nitrate hexahydrate (0.02-0.08 M) and hexamethylenetetramine (0.02-0.08 M). ZnO nanorods having diameter of 50-70 nm and with length up to 120 nm were obtained at reactant concentration of 0.04 M. The ZnO nanorods started to merge with each other and formed irregular nanostructures vertically on the substrates at higher reactant concentrations of 0.06 M and 0.08 M. The solar cell with ZnO nanorods prepared at reactant concentration of 0.04 M provided the largest interface area between polymer active layer and ZnO, resulting in the highest power conversion efficiency of 0.053 % with short circuit current density of 0.43 mA/cm2, open circuit voltage of 0.42 V and fill factor of 29 %.

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