scholarly journals Si/ZnO nanorods with Ag nanoparticles/AZO heterostructures in PV applications

2016 ◽  
Vol 64 (3) ◽  
pp. 529-533
Author(s):  
K. Gwóźdź ◽  
E. Płaczek-Popko ◽  
Z. Gumienny ◽  
E. Zielony ◽  
R. Pietruszka ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
Zno Nanorods ◽  
Spectral Characteristics ◽  
Hexagonal Wurtzite Structure ◽  
Atomic Layer ◽  
Transparent Electrode ◽  
Zinc Oxide Nanorods ◽  
Sem Images ◽  
Before And After ◽  
P Type

Abstract Our studies focus on test structures for photovoltaic applications based on zinc oxide nanorods grown using a low-temperature hydrothermal method on a p-type silicon substrate. The nanorods were covered with silver nanoparticles of two diameters – 20–30 nm and 50–60 nm – using a sputtering method. Scanning electron microscopy (SEM) micrographs showed that the deposited nanoparticles had the same diameters. The densities of the nanorods were obtained by means of atomic force microscope (AFM) images. SEM images and Raman spectroscopy confirmed the hexagonal wurtzite structure of the nanorods. Photoluminescence measurements proved the good quality of the samples. Afterwards an atomic layer deposition (ALD) method was used to grow ZnO:Al (AZO) layer on top of the nanorods as a transparent electrode and ohmic Au contacts were deposited onto the silicon substrate. For the solar cells prepared in that manner the current-voltage (I-V) characteristics before and after the illumination were measured and their basic performance parameters were determined. It was found that the spectral characteristics of a quantum efficiency exhibit an increase for short wavelengths and this behavior has been linked with the plasmonic effect.

scholarly journals Photovoltaic properties of ZnO nanorods/p-type Si heterojunction structures

2014 ◽  
Vol 5 ◽  
pp. 173-179 ◽  
Author(s):  
Rafal Pietruszka ◽  
Bartlomiej Slawomir Witkowski ◽  
Grzegorz Luka ◽  
Lukasz Wachnicki ◽  
Sylwia Gieraltowska ◽  
...  
Keyword(s):  
Zno Nanorods ◽  
Atomic Layer ◽  
Zinc Oxide Nanorods ◽  
Silicon Substrates ◽  
Photovoltaic Properties ◽  
Best Response ◽  
Layer Deposition ◽  
Oxide Nanorods ◽  
P Type ◽  
Light Conversion Efficiency

Selected properties of photovoltaic (PV) structures based on n-type zinc oxide nanorods grown by a low temperature hydrothermal method on p-type silicon substrates (100) are investigated. PV structures were covered with thin films of Al doped ZnO grown by atomic layer deposition acting as transparent electrodes. The investigated PV structures differ in terms of the shapes and densities of their nanorods. The best response is observed for the structure containing closely-spaced nanorods, which show light conversion efficiency of 3.6%.

Effect of Annealing Temperature of Magnesium Doped Zinc Oxide Nanorods Growth on Silicon Substrate

2013 ◽  
Vol 26 ◽  
pp. 33-38 ◽  
Author(s):  
Ruziana Mohamed ◽  
Zuraida Khusaimi ◽  
A.N. Afaah ◽  
Aadila Aziz ◽  
Mohamad Hafiz Mamat ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
Annealing Temperature ◽  
Zno Nanorods ◽  
Zinc Oxide Nanorods ◽  
Immersion Method ◽  
Xrd Diffraction ◽  
Zinc Oxides ◽  
Good Crystallinity ◽  
Oxide Nanorods ◽  
Mg Doped

Magnesium (Mg)-doped zinc oxides (ZnO) have been prepared on a silicon substrate by using the solution-immersion method. The nanorods films were annealed at different temperature 0°C, 250°C, 500°C respectively for 1 hour. The XRD diffraction indicated that the Mg-doped ZnO nanorods have good crystallinity with a hexagonal wurzite structure preferentially oriented along the (002) direction. PL spectroscopy at room temperature shows strong UV peaks appearing at 383 nm when annealed at 250°C. The intensity of broad emission peaks increases with increasing annealing temperature to 500°C which is possibility attributed to intrinsic defects.

Low-Temperature Cathodoluminescence Investigations of High-Quality Zinc Oxide Nanorods

2015 ◽  
Vol 21 (3) ◽  
pp. 564-569 ◽  
Author(s):  
Bartlomiej S. Witkowski ◽  
Lukasz Wachnicki ◽  
Sylwia Gieraltowska ◽  
Anna Reszka ◽  
Bogdan J. Kowalski ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Radiation Effects ◽  
Zno Nanorods ◽  
Zinc Oxide Nanorods ◽  
Nanorod Arrays ◽  
High Quality ◽  
Sem Images ◽  
Oxide Nanorods ◽  
Very High

AbstractWe present results of cathodoluminescence (CL) investigations of high-quality zinc oxide (ZnO) nanorods obtained by an extremely fast hydrothermal method on a silicon substrate. A scanning electron microscopy (SEM) system equipped with CL allows direct comparison of SEM images and CL maps, taken from exactly the same areas of samples. Investigations are performed at a temperature of 5 K. An interlink between sample microstructure and emission properties is investigated. CL confirms a very high quality of ZnO nanorods produced by our method. In addition, the presence of super radiation effects in ZnO nanorod arrays is suggested.

scholarly journals Graphene Oxide Concentration Effect on the Optoelectronic Properties of ZnO/GO Nanocomposites

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1532
Author(s):  
Issam Boukhoubza ◽  
Mohammed Khenfouch ◽  
Mohamed Achehboune ◽  
Liviu Leontie ◽  
Aurelian Catalin Galca ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Color Space ◽  
Hexagonal Wurtzite Structure ◽  
Zinc Oxide Nanorods ◽  
Luminescence Properties ◽  
A Charge ◽  
Average Coherence ◽  
The Impact

In this work, the effects of graphene oxide (GO) concentrations (1.5 wt.%, 2.5 wt.%, and 5 wt.%) on the structural, morphological, optical, and luminescence properties of zinc oxide nanorods (ZnO NRs)/GO nanocomposites, synthesized by a facile hydrothermal process, were investigated. X-ray diffraction (XRD) patterns of NRs revealed the hexagonal wurtzite structure for all composites with an average coherence length of about 40–60 nm. A scanning electron microscopy (SEM) study confirmed the presence of transparent and wrinkled, dense GO nanosheets among flower-like ZnO nanorods, depending on the GO amounts used in preparation. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) absorption spectroscopy, and photoluminescence (PL) measurements revealed the impact of GO concentration on the optical and luminescence properties of ZnO NRs/GO nanocomposites. The energy band gap of the ZnO nanorods was independent of GO concentration. Photoluminescence spectra of nanocomposites showed a significant decrease in the intensities in the visible light range and red shifted suggesting a charge transfer process. The nanocomposites’ chromaticity coordinates for CIE 1931 color space were estimated to be (0.33, 0.34), close to pure white ones. The obtained results highlight the possibility of using these nanocomposites to achieve good performance and suitability for optoelectronic applications.

scholarly journals Study on Fabrication and Material Properties of Al Doped ZnO Films Prepared by Atmospheric Atomic Layer Deposition

2021 ◽  
Vol 31 (4) ◽  
pp. 85-92
Keyword(s):  
Atomic Layer Deposition ◽  
Room Temperature ◽  
Hexagonal Wurtzite Structure ◽  
Atomic Layer ◽  
High Resistivity ◽  
Zno Films ◽  
Experimental Conditions ◽  
Layer Deposition ◽  
Measurement Results ◽  
P Type

This paper presents the study on aluminium-doped zinc oxide (AZO) films prepared by atmospheric atomic layer deposition (AALD) using Diethylzinc (DEZ), Zn(C2H5)2, and Trimethylaluminum (TMA), Al(CH3)3 as precursors. The optimal condition for doping was investigated by changing in DEZ/TMA ratio. The crystal structure of fabricated thin films shows the hexagonal wurtzite structure with the orientation along the c-axis. The influence of heat treatment on the grain size, carrier type and concentration of post-fabricated films deposited on the different substrates which are borosilicate glass and sapphire was also analysed. The Hall measurement to determine the carrier type and resistivity at room temperature to 400oC was performed. The measurement results show that as-deposited samples behave as alloy-like property with p-type carriers and high resistivity. However, they turned into n-type nature as expected with the increase in carrier concentration and consequently the marked decrease in electrical resistance when annealed at the higher temperatures that are at 500oC and 900oC (i.e, 773 and 1173 K). In general, the obtained films with optimized experimental conditions of as- and post-fabrication can be used for thermoelectric applications.

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 Visible Photoluminescence of Variable-Length Zinc Oxide Nanorods Embedded in Porous Anodic Alumina Template for Biosensor Applications

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 756
Author(s):  
Uldis Malinovskis ◽  
Aleksandrs Dutovs ◽  
Raimonds Poplausks ◽  
Daniels Jevdokimovs ◽  
Octavio Graniel ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Composite Film ◽  
Zno Nanorods ◽  
Synthesis Method ◽  
Intensity Variation ◽  
Atomic Layer ◽  
Variable Length ◽  
Zinc Oxide Nanorods ◽  
Blue Component ◽  
Optical Applications

Zinc oxide (ZnO) and porous anodic aluminum oxide (PAAO) are technologically important materials, rich with features that are of interest in optical applications, for example, in light-emitting and sensing devices. Here, we present synthesis method of aligned ZnO nanorods (NR) with 40 nm diameter and variable length in 150 to 500 nm range obtained by atomic layer deposition (ALD) of ZnO in pores of continuously variable thickness PAAO. The relative intensity of yellow (1.99 eV), green (2.35 eV), and blue (2.82 eV) photoluminescence (PL) components originating from the different types of defects, varied with non-monotonic dependency on the composite film thickness with a Fabry–Pérot like modulation. The intensity variation of any individual PL component correlated well with anti-reflective properties of ZnO NR–PAAO composite film at the peak wavelength of the particular PL component. This provides a route for selective enhancement or suppression of color components of hybrid fluorescent emitters by tuning only geometric parameters, with potential use in imaging and other optical devices. As an application example we tested the composite film for sensing of vascular endothelial growth factor (VEGF) using a widely accessible fluorescence microscopy setup. The intensity of the yellow and green PL components reduced in response to increased VEGF concentrations, whereas blue component remained invariant.

scholarly journals Morphology and structure study of polygon ZnO nanorods: Biomedical applications

2021 ◽  
Vol 3 (1) ◽  
pp. 125-132
Author(s):  
Parastoo Khalili ◽  
◽  
Majid Farahmandjou ◽  
Keyword(s):  
Electron Microscopy ◽  
Zno Nanorods ◽  
Hexagonal Wurtzite Structure ◽  
Structure Study ◽  
Precipitation Method ◽  
Zno Nps ◽  
Sem Images ◽  
Tem Analysis ◽  
Exact Size ◽  
Co Precipitation

In this study, zinc oxide (ZnO) nanoparticles (NPs) were first synthesized using co-precipitation method in the presence of Zn(NO3)2.6H2O precursor and calcined at different temperature of 450 oC and 1000 oC. Samples were then characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The XRD study revealed the hexagonal wurtzite structure for annealed samples. SEM images showed tthat he morphology of the ZnO NPs changed from sphere-like shape to polygon shape by increasing temperature. The exact size of NPs were measured by TEM analysis about 40 nm for as-prepared samples. The EDS analysis demonstrated an increasing level of Zn element from 28.5 wt% to 50.8 wt% for as-synthesized and annealed samples, respectively.

Photoresistor based on ZnO nanorods grown on a p-type silicon substrate

2017 ◽  
Vol 25 (1) ◽  
pp. 15-18 ◽  
Author(s):  
B.S. Witkowski ◽  
R. Pietruszka ◽  
S. Gieraltowska ◽  
L. Wachnicki ◽  
H. Przybylinska ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
Zno Nanorods ◽  
Type Silicon ◽  
P Type

Ergonomic Synthesis Suitable for Industrial Production of Silver-Festooned Zinc Oxide Nanorods

2015 ◽  
Vol 14 (05n06) ◽  
pp. 1550018 ◽  
Author(s):  
G. R. Khan ◽  
R. A. Khan
Keyword(s):  
Electron Microscopy ◽  
Industrial Production ◽  
Zno Nanorods ◽  
Nir Spectroscopy ◽  
Hexagonal Wurtzite Structure ◽  
Single Step ◽  
Zinc Oxide Nanorods ◽  
Average Particle ◽  
Wurtzite Phase ◽  
Doped Zno

For maximizing productivity, minimizing cost, time-boxing process and optimizing human effort, a single-step, cost-effective, ultra-fast and environmentally benign synthesis suitable for industrial production of nanocrystalline ZnO , and Ag -doped ZnO has been reported in this paper. The synthesis based on microwave-supported aqueous solution method used zinc acetate dehydrate and silver nitrate as precursors for fabrication of nanorods. The synthesized products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and UV-Vis–NIR spectroscopy. The undoped and Ag -doped ZnO nanorods crystallized in a hexagonal wurtzite structure having spindle-like morphology. The blue shift occurred at absorption edge of Ag -doped ZnO around 260 nm compared to 365 nm of bulk ZnO . The red shift occurred at Raman peak site of 434 cm-1 compared to characteristic wurtzite phase peak of ZnO (437 cm-1). The bandgap energies were found to be 3.10 eV, 3.11 eV and 3.18 eV for undoped, 1% Ag -doped, and 3% Ag -doped ZnO samples, respectively. The TEM results provided average particle sizes of 17 nm, 15 nm and 13 nm for undoped, and 1% and 3% Ag -doped ZnO samples, respectively.

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