Morphology modification of ZnO nanosheets and ZnO nanorods via thermal dissipation system for UV photoresponse improvement

2022 ◽  
Vol 138 ◽  
pp. 106286
Author(s):  
Dongwan Kim ◽  
Jae-Young Leem
Keyword(s):  
Zno Nanorods ◽  
Thermal Dissipation ◽  
Zno Nanosheets ◽  
Morphology Modification ◽  
Dissipation System

One-Step Hydrothermal Synthesis and Characterization of ZnO Nanopowders

2011 ◽  
Vol 110-116 ◽  
pp. 1928-1933 ◽  
Author(s):  
Yan Xiang Wang ◽  
Xiao Yan Li ◽  
Jian Sun ◽  
Yao Hui Hu
Keyword(s):  
Hydrothermal Synthesis ◽  
Raw Materials ◽  
Zno Nanorods ◽  
Synthesis Temperature ◽  
Molar Concentration ◽  
Zno Nanosheets ◽  
Length Width ◽  
One Step ◽  
Lower Temperature

In the paper, ZnO nanopowders were synthesized by one-step hydrothermal synthesis using zinc acetate and sodium hydroxide as raw materials. The influences of molar concentration of NaOH and synthesis temperature on the properties of ZnO nanopowders were investigated. XRD and FSEM were used to characterize ZnO nanopowders. The results showed that; when the molar concentration of NaOH was 0.05 mol/L, 1mol/L and 2mol/L, ZnO micrometer powders were obtained. When the molar concentration of NaOH was 4mol/L, ZnO nanorods or nanosheets were obtained with different reaction temperature. When the temperature was 220°C, ZnO nanorods with the length of 500nm and diameter of 100nm, were synthesised. Pure ZnO nanopowders can be obtained at lower temperature of 100°C by using one-step hydrothermal synthesis. When the synthesis temperature was 100°C and the molar concentration of NaOH was 4mol/L, ZnO nanosheets were produced. The length, width and thickness of ZnO nanosheets were about 800 nm, 500nm and 80nm, respectively.

Effect of Addition of KI on the Hydrothermal Growth of ZnO Nanostructures Towards Hybrid Optoelectronic Device Applications

2016 ◽  
Vol 16 (4) ◽  
pp. 3301-3306 ◽  
Author(s):  
Anubha Bilgaiyan ◽  
Tejendra Dixit ◽  
Gaurav Kapil ◽  
Shyam S Pandey ◽  
Shuji Hayase ◽  
...  
Keyword(s):  
Defect Density ◽  
Zno Nanorods ◽  
Optoelectronic Device ◽  
Hydrothermal Growth ◽  
Visible Range ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Zno Nanosheets ◽  
Device Applications ◽  
Structural And Optoelectronic Properties

We report the structural and optoelectronic properties of Zinc oxide (ZnO) nanostructures prepared by hydrothermal method. The morphological, structural and optical properties of the grown ZnO nanostructures were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence spectroscopy (PL) respectively. Upon addition of relatively small amount of KI during the in-situ hydrothermal growth the nanorods were formed, further increasing the concentration led to increased diameter of these nanorods and finally at relatively higher concentration of KI, ZnO nanosheets were formed. Later these structures were used to fabricate bi-layer ZnO/P3HT based hybrid photodiode. Subsequent hybrid photodiode measurement with ZnO nanorods and ZnO nanosheets indicated that the nanosheets exhibited improved photodiode response. Compared to the ZnO nanorod/P3HT devices, the optimized photodiode with the dense ZnO nanosheets/P3HT have shown significant increase in the rectification ratio and the photosenstivity from 3.21 to 1420 and from 5.85 to 1330 respectively. The enhanced photodiode response of bi-layered devices consisting of ZnO nanosheets indicated that optimizing the shape and size of ZnO nanostructures had a significant influence on the overall photocurrent and the observed results have been explained on the basis of reduction in the defect density with pronounced absorption in the UV region, thus leading to improved transmission of light in the visible range through these layers.

Effect of Surfactants on the Morphologies of ZnO Nanostructures Synthesized by Hydrothermal Method and its Gas Sensitivity to Formaldehyde

2010 ◽  
Vol 159 ◽  
pp. 628-633 ◽  
Author(s):  
Kai Jin Huang ◽  
Li Yan ◽  
Chang Sheng Xie
Keyword(s):  
Citric Acid ◽  
Polyvinyl Alcohol ◽  
Hydrothermal Method ◽  
Zno Nanorods ◽  
Alumina Substrate ◽  
Zno Nanostructures ◽  
Growth Mechanisms ◽  
Gas Sensitivity ◽  
Nano Zno ◽  
Zno Nanosheets

Based on the principle of the higher surface-to-volume ratios, the higher formaldehyde gas sensitivity, different morphologies’s ZnO nanostructures have been synthesized by hydrother- mal method using different surfactants including polyvinyl alcohol (PVA), cetyltrimethyl ammon- ium bromide (CTAB), sodium tripolyp hosphate (STPP) and citric acid(CA). The crystal structur- es and morphologies were characterized by XRD and FESEM. The results show that different morphologies’s ZnO nanostructures were induced on the surface of alumina substrate, and the surfactants had an important effect on the morphologies of ZnO nanostructures and then affected the formaldehyde gas sensitivity. The ZnO nanorods with diameters of 100-500 nm and lengths of 200-900nm were obtained using PVA surfactant. The ZnO nanosheets with thickness of about 10nm were obtained using CTAB surfactant. The ZnO nanodisks with two layers and thickness of 5-10nm were obtained using STPP surfactant. The ZnO microspheres composed of thin flakes with thickness of about 10 nm were obtained using CA surfactant. The growth mechanisms of different morphologies’s ZnO nanostructures using different surfactants were given in detail. In addition, the formaldehyde gas sensitivities of different morphologies’s ZnO nanostructures were measured and showed the higher formaldehyde gas sensitivity compared with nano-ZnO without surfactant.

Preparation of ZnO Nanopowders by One-Step Hydrothermal Synthesis

2011 ◽  
Vol 412 ◽  
pp. 21-24
Author(s):  
Yan Xiang Wang ◽  
Jian Sun ◽  
Xiao Yan Li
Keyword(s):  
Polyethylene Glycol ◽  
Raw Materials ◽  
Zno Nanorods ◽  
Synthesis Temperature ◽  
Soft Template ◽  
Peg 400 ◽  
Zno Nanosheets ◽  
Length Width ◽  
One Step ◽  
Soft Templates

In the paper, ZnO nanopowders were synthesized by using zinc acetate and sodium hydroxide as raw materials. The influences of different soft templates and synthesis temperature on the properties of ZnO nanopowders were investigated. The results showed that: when using the polyethylene glycol (PEG (400)) or polyvinyl alcohol (PVA) as soft template, the ZnO nanoparticles with the diameter about 100nm were obtained, whereas the ZnO nanorods which the length and diameter were 300nm and 150nm respectively were obtained without soft template. When the synthesis temperature was 220°C and 70°C, the ZnO nanorods were obtained. When the temperature was 100°C, the ZnO nanosheets were produced, and the length, width and thickness of ZnO nanosheets were about 800 nm, 500nm and 80nm, respectively. When the temperature was 90°C, the ZnO nanosheets composed with nanorods were prepared.

scholarly journals Transparent and flexible ZnO nanorods induced by thermal dissipation annealing without polymer substrate deformation for next-generation wearable devices

RSC Advances ◽  
2021 ◽  
Vol 11 (29) ◽  
pp. 17538-17546
Author(s):  
Dongwan Kim ◽  
Jae-Young Leem
Keyword(s):  
Seed Layer ◽  
Zno Nanorods ◽  
Wearable Devices ◽  
Polymer Substrate ◽  
Thermal Dissipation ◽  
Next Generation ◽  
Uv Photodetector ◽  
High Photosensitivity

A transparent and flexible ultraviolet (UV) photodetector based on ZnO nanorods grown onto the thermal dissipation annealed ZnO seed layer exhibited high photosensitivity, photoresponsivity, and photocurrent stability without substrate deformation.

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