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.

scholarly journals Studies on the Growth Control of ZnO Nanostructures synthesized by the Chemical Method

2018 ◽  
Vol 23 (2) ◽  
Author(s):  
Patricia María Perillo ◽  
Mariel Nahir Atia ◽  
Daniel Fabián Rodríguez
Keyword(s):  
Chemical Method ◽  
Morphological Evolution ◽  
Zno Nanorods ◽  
Growth Control ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Wurtzite Phase ◽  
X Ray ◽  
Hexagonal Wurtzite Phase

ABSTRACT ZnO nanostructures were synthesized through a chemical method using different Zn precursors and hexamethylenetetramine (HMTA) at 90 °C. The effects of the reactants on the morphological evolution of ZnO nanorods were investigated. The samples were characterized by using XRD, SEM, EDX and BET. The hexagonal wurtzite phase of ZnO was confirmed by X-ray diffraction (XRD). The performed analysis indicated that different morphologies were obtained by changing the reactants.

Optical, electrical, and structural properties of Fe-doped CuAlO2 thin films

2019 ◽  
Vol 12 (01) ◽  
pp. 1850106
Author(s):  
Xueping Zhao ◽  
Ming Zhang ◽  
Pucun Bai ◽  
Xiaohu Hou ◽  
Fei Liu ◽  
...  
Keyword(s):  
Optical Band Gap ◽  
Impurity Band ◽  
Optical Transmittance ◽  
Visible Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fe Content ◽  
Average Transmittance ◽  
Concentration Enhancement ◽  
Structural And Optoelectronic Properties

The influence of Fe content on the structural and optoelectronic properties of Fe-doped CuAlO2 films was studied. X-ray diffraction (XRD) results revealed that all annealed films had a pure delafossite phase. Optical transmittance spectra showed that Fe-doped films exhibit an obvious change in the 340–380[Formula: see text]nm region compared to undoped CuAlO2, and optical band gap analyses confirmed the formation of impurity band levels within the bandgap. The average transmittance of CuAl[Formula: see text]FexO2 is around 45–55% in the visible range, and transmittance in this region decreases with increasing Fe concentration. Increased conductivity was observed due to the introduction of Fe and subsequent carrier concentration enhancement. The conductivity in a CuAl[Formula: see text]Fe[Formula: see text]O2 film was maximized at [Formula: see text][Formula: see text]S[Formula: see text]cm[Formula: see text].

PERFORMANCE OF pH SENSOR ELECTRODE BASED ON ZnO NRs ON FTO-GLASS SUBSTRATE

2020 ◽  
Vol 27 (08) ◽  
pp. 1950198
Author(s):  
ABDULQADER D. FAISAL ◽  
MOHAMMAD O. DAWOOD ◽  
HASSAN H. HUSSEIN ◽  
KHALEEL I. HASSOON
Keyword(s):  
Seed Layer ◽  
Zno Nanorods ◽  
Ph Sensor ◽  
High Sensitivity ◽  
Hydrothermal Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Electrode Cell ◽  
Fto Glass

In this work, ZnO nanorods (ZnO NRs) were successfully synthesized on FTO-glass via hydrothermal technique. Two steps were followed to grow ZnO NRs. In the first step, the seed layer of ZnO nanocrystals was deposited by using a drop cast method. The second step was represented by the hydrothermal growth of ZnO NRs on a pre-coated FTO- glass with the seed layer. The hydrothermal growth was conducted at 90∘C for 2[Formula: see text]h. The resulted structure, morphology and optical properties of the produced layers were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) and UV-visible spectrophotometer, respectively. The analysis confirmed that the ZnO NRs grown by the hydrothermal method have a hexagonal crystal structure which was grown randomly on the FTO surface. The crystallite size was recorded 50[Formula: see text]nm and a slight microstrain (0.142%) was calculated. The bandgap was found to be in the range of 3.14–3.17[Formula: see text]eV. The ZnO NRs have a high density and large aspect ratio. A pH sensor with high sensitivity was fabricated using a two-electrode cell configuration. The ZnO NRs sensor showed the sensitivity of [Formula: see text]59.03[Formula: see text]mV/pH, which is quite promising and close to the theoretical value ([Formula: see text]59.12[Formula: see text]mV/pH).

scholarly journals Investigation on optical, electrical and etching properties of 2-aminopyridinium 4-aminobenzoate: A phase matchable organic single crystal for optoelectronic device applications

2017 ◽  
Vol 35 (1) ◽  
pp. 126-134 ◽  
Author(s):  
L. Chandra ◽  
J. Chandrasekaran ◽  
K. Perumal ◽  
B. Babu ◽  
V. Jayaramakrishnan
Keyword(s):  
Optoelectronic Device ◽  
Spectroscopic Studies ◽  
Average Particle ◽  
Dielectric Study ◽  
X Ray Diffraction ◽  
Device Applications ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Homo Lumo

AbstractNLO active 2-aminopyridinium 4-aminobenzoate (APAB) single crystals were successfully grown by the standard slow evaporation technique. The crystallinity of the grown crystals was analyzed through X-ray diffraction (XRD) measurements. Fourier transform infrared (FT-IR) spectroscopic studies were also performed for the identification of different modes present in the compound. The UV-Vis absorption and transmittance spectra were recorded for the grown crystal and the optical band gap was calculated. Birefringence and etching studies were also carried out. The dielectric study showed that the dielectric constant decreased with an increase in frequency. The photoconductivity study revealed its positive photoconducting nature. Theoretical HOMO LUMO investigations were also made for the crystal. The relative SHG efficiency of the material was investigated by the Kurtz and Perry powder technique. The phase matching property of the crystal was studied through the SHG dependence of average particle sizes.

scholarly journals Fabrication of ZnO nanorods for optoelectronic device applications

2009 ◽  
Vol 83 (4) ◽  
pp. 553-558 ◽  
Author(s):  
R. Chakraborty ◽  
U. Das ◽  
D. Mohanta ◽  
A. Choudhury
Keyword(s):  
Zno Nanorods ◽  
Optoelectronic Device ◽  
Device Applications

The Effect of Cooling Rate During the Hydrothermal Growth on the Tip Geometry of ZnO Nanorods

2012 ◽  
Vol 602-604 ◽  
pp. 144-147
Author(s):  
He Qiu Zhang ◽  
Xiu Ming Ren ◽  
Li Zhong Hu ◽  
Jiu Yu Ji ◽  
Yang Li ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Hexagonal Phase ◽  
Zno Nanorods ◽  
Critical Factor ◽  
Hydrothermal Growth ◽  
Water Cooling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cooling Conditions ◽  
Structural Characterizations

The ZnO nanorods with sharp tip have been fabricated via water cooling treatment during the hydrothermal growth. The morphology and crystal structure of the zinc oxide nanostructure were examined by field-emission scanning electron microscopy and x-ray diffraction, respectively. The structural characterizations revealed that the as-synthesized nanorods were single crystalline, with a hexagonal phase. It has been demonstrated that the cooling rate is the critical factor of the synthesis of the sharp tip ZnO nanorods by comparing the different cooling conditions. The growth mechanism for the sharp tip ZnO nanorods has been proposed on the basis of the different crystallographic habits of wurtzite hexagonal ZnO crystals.

scholarly journals Crystal growth of nanostructured zinc oxide nanorods from the seed layer

2018 ◽  
Vol 36 (3) ◽  
pp. 477-482
Author(s):  
B.O. Adetoye ◽  
A.B. Alabi ◽  
T. Akomolafe ◽  
P.B. Managutti ◽  
N. Coppede ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Absorption Spectrum ◽  
Zno Nanorods ◽  
Zinc Oxide Nanorods ◽  
Visible Range ◽  
Zno Nanostructures ◽  
Sem Images ◽  
Zno Nanostructure ◽  
Vis Spectroscopy ◽  
Fto Glass

AbstractOne-dimensional (1D) zinc oxide (ZnO) nanostructures (nanorods) were synthesized on a glass slide and fluorine-doped tin oxide (SnO2/F or FTO) coated glass (FTO/glass) by a wet chemical method. The structural, morphological and optical analyses of the as-deposited ZnO nanostructures were performed by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and UV-Vis spectroscopy, respectively. The XRD results showed that the nanostructures as-deposited on the glass and the FTO/glass substrates were of ZnO wurtzite crystal structure, and the crystallite sizes estimated from the (0 0 2) planes were 60.832 nm and 64.876 nm, respectively. The SEM images showed the growth of densely oriented ZnO nanorods with a hexagonal-faceted morphology. The UV-Vis absorption spectrum revealed high absorbance properties in the ultraviolet range and low absorbance properties in the visible range. The optical energy band gap of the ZnO nanostructure was estimated to be 3.87 eV by the absorption spectrum fitting (ASF) method.

scholarly journals Electrical suppression of all nonradiative recombination pathways in monolayer semiconductors

Science ◽  
2019 ◽  
Vol 364 (6439) ◽  
pp. 468-471 ◽  
Author(s):  
Der-Hsien Lien ◽  
Shiekh Zia Uddin ◽  
Matthew Yeh ◽  
Matin Amani ◽  
Hyungjin Kim ◽  
...  
Keyword(s):  
Defect Density ◽  
Transition Metal Dichalcogenides ◽  
Optoelectronic Device ◽  
Nonradiative Recombination ◽  
Native Defect ◽  
Stringent Requirement ◽  
Electrostatic Doping ◽  
Metal Dichalcogenides ◽  
Device Applications ◽  
Chemical Passivation

Defects in conventional semiconductors substantially lower the photoluminescence (PL) quantum yield (QY), a key metric of optoelectronic performance that directly dictates the maximum device efficiency. Two-dimensional transition-metal dichalcogenides (TMDCs), such as monolayer MoS2, often exhibit low PL QY for as-processed samples, which has typically been attributed to a large native defect density. We show that the PL QY of as-processed MoS2 and WS2 monolayers reaches near-unity when they are made intrinsic through electrostatic doping, without any chemical passivation. Surprisingly, neutral exciton recombination is entirely radiative even in the presence of a high native defect density. This finding enables TMDC monolayers for optoelectronic device applications as the stringent requirement of low defect density is eased.

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