liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The impact of ion irradiation on morphology, structure and optical properties of ZnO nanowires
Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
Show others and affiliations
2008 (English)Manuscript (preprint) (Other academic)
Abstract [en]

Chemically grown ZnO nanowires were irradiated with ions and subsequently investigated by continues wave (cw) photoluminescence (PL) and time resolved PL (TRPL) both at room (300 K) and low (10 K) temperatures, and was compared with the as-grown samples. The ion bombardment was done by using 30 keV argon, and 40 MeV iodine ions using ion fluencies of 3 ×1016 ions/cm2, and 1.3 ×1013 ions/cm2, respectively. Scanning electron microscopy (SEM) images and X-ray diffraction (XRD) spectra showed that the morphology and structure of the ion irradiated ZnO nanowires were less damaged. Using the PL and XRD spectra the induced compressive strains in the irradiated samples was calculated. Also there was a decrease and increase in the XRD intensity which had emphasized that some texture modification occurred in the irradiated samples. No severe decomposition of the irradiated samples was observed. The PL measurements showed that the intensity of the near band emission (free exciton) of the irradiated ZnO nanowires was decreased for all irradiating ions, whereas the deep emission band was enhanced for iodine ions and suppressed for argon ions irradiated samples. A blue peak shift (~ 2 meV) of the excitonic emission of the irradiated samples was observed. The TRPL spectra for the as-grown and the irradiated ZnO nanowires were fitted with single and two components time decay constant, respectively.

Place, publisher, year, edition, pages
2008. Vol. 104, no 10, 104306- p.
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:liu:diva-65402OAI: oai:DiVA.org:liu-65402DiVA: diva2:395454
Available from: 2011-02-07 Created: 2011-02-07 Last updated: 2014-01-15Bibliographically approved
In thesis
1. Mechanical Characterization and Electrochemical Sensor Applications of Zinc Oxide Nanostructures
Open this publication in new window or tab >>Mechanical Characterization and Electrochemical Sensor Applications of Zinc Oxide Nanostructures
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanotechnology is emerging to be one of the most important scientific disciplines that physics, chemistry and biology truly overlap with each other. Over the last two decades science and technology have witnessed tremendous improvement in the hope of unveiling the true secrets of the nature in molecular or atomic level. Today, the regime of nanometer is truly reached.

ZnO is a promising material due to the wide direct band gap (3.37 eV) and the room temperature large exciton binding energy (60 meV). Recent studies have shown considerable attraction towards ZnO nanostructures, particularly on one-dimensional ZnO nanorods, nanowires, and nanotubes due to the fact that, for a large number of applications, shape and size of the ZnO nanostructures play a vital role for the performance of the devices. The noncentrosymmetric property of ZnO makes it an ideal piezoelectric material for nanomechanical devices. Thus, mechanical characterization of one dimensional ZnO nanostructures including strength, toughness, stiffness, hardness, and adhesion to the substrate is very important for the reliability and efficient operation of piezoelectric ZnO nanodevices. Moreover, owing to the large effective surface area with high surface-to-volume ratio, the surface of one dimensional ZnO nanowires, nanorods, and nanotubes is very sensitive to the changes in surface chemistry and hence can be utilized to fabricate highly sensitive ZnO electrochemical sensors.

This thesis studies mechanical properties and electrochemical sensor applications of ZnO nanostructures.

The first part of the thesis deals with mechanical characterization of vertically grown ZnO nanorods and nanotubes including buckling, mechanical instability, and bending flexibility. In paper I, we have investigated mechanical instability and buckling characterization of vertically aligned single-crystal ZnO nanorods grown on Si, SiC, and sapphire substrates by vapor-liquid-solid (VLS) method. The critical loads for the ZnO nanorods grown on Si, SiC, and sapphire were measured and the corresponding buckling and adhesion energies were calculated. It was found that the nanorods grown on SiC substrate have less residual stresses and are more stable than the nanorods grown on Si and sapphire substrates.

Paper II investigates nanomechanical tests of bending flexibility, kinking, and buckling failure characterization of vertically aligned single crystal ZnO nanorods/nanowires grown by VLS and aqueous chemical growth (ACG) methods. We observed that the loading and unloading behaviors during the bending test of the as-grown samples were highly symmetrical and the highest point on the bending curves and the first inflection and critical point were very close. The results also show that the elasticity of the ZnO single crystal is approximately linear up to the first inflection point and is independent of the growth method.

In Paper III, we quantitatively investigated the buckling and the elastic stability of vertically well aligned ZnO nanorods and ZnO nanotubes grown on Si substrate by nanoindentation technique. We found that the critical load for the nanorods was five times larger than the critical load for nanotubes. On the contrary, the flexibility for nanotubes was five times larger than nanorods. The discovery of high flexibility for nanotubes and high elasticity for nanorods can be utilized for designing efficient piezoelectric nanodevices.

The second part of this thesis investigates electrochemical sensor applications of ZnO nanorods, nanotubes , and nanoporous material.

In paper IV, we utilized functionalized ZnO nanorods on the tip of a borosilicate glass capillary coated with ionophore-membrane to construct intracellular Ca2+ selective sensor. The sensor exhibited a Ca2+-dependent electrochemical potential difference and the response was linear over a large dynamic concentration range, which enabled this sensor to measure Ca2+ concentrations in human adipocytes or in frog oocytes. The results were consistent with the values of Ca2+ concentrations reported in the literature.

In paper V, ZnO nanotubes and nanorods were used to create pH sensor devices. The developed ZnO pH sensors display good reproducibility, repeatability, and long-term stability. The ZnO pH sensors exhibited a pH-dependent electrochemical potential difference over a large dynamic pH range. We found that the ZnO nanotubes provide sensitivity as high as twice that of the ZnO nanorods. The possible reasons of enhanced sensitivity were explained.

Paper VI investigates an improved potentiometric intracellular glucose biosensor based on the immobilization of glucose oxidase on the ZnO nanoporous material. We demonstrated that using ZnO nanoporous material as a matrix material for enzyme immobilization improves the sensitivity of the biosensor as compared to using ZnO nanorods. In addition, the fabrication method of the intracellular biosensor was simple and excellent performance in sensitivity, stability, selectivity, reproducibility, and anti-interference was achieved.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2010. 61 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1323
Keyword
Nanotechnology, Zinc Oxide, nanorods, nanotubes, nanoporous, buckling, electrochemical sensor
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-57297 (URN)978-91-7393-369-8 (ISBN)
Public defence
2010-06-04, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:15
Opponent
Supervisors
Available from: 2010-06-16 Created: 2010-06-16 Last updated: 2014-01-15Bibliographically approved
2. Elastic Stability and Piezoelectric Power Generation Using ZnO Nanostructures
Open this publication in new window or tab >>Elastic Stability and Piezoelectric Power Generation Using ZnO Nanostructures
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanotechnology combines the effort between science and engineering using the approaches of either top-to-bottom or bottom-to-top techniques. A hybrid approach of the above techniques is also used for the fabrication of nanodevices. In nanotechnology one and zero dimensional structures are considered as the basic building blocks for multidimensional systems. One dimensional nanostructure such as nanorods, nanowires and nanotubes has become the research core of science and engineering, because of their unique and interesting properties for device applications.

In this thesis a mechanical property i.e. elastic stability, the behavior of piezoelectric power nanogenerator and the effects of ions irradiations were investigated for ZnO nanostructures.

Buckling phenomena was employed for the elastic stability investigation using Hysitron nanoindentor. ZnO nanostructures were loaded axially to a prescribed controlled load and then unloaded in the same fashion by the tip of a nanoindentor to investigate the first critical load and other unstable configurations. The present buckling study concluded that the elastic stability of ZnO nanostructures were mainly dependent on the slenderness ratio and the verticality of the structures to the substrates.

Piezoelectric power nanogenerators were investigated using ZnO nanowires. The performance of different piezoelectric power nanogenerators were observed on the bases of the aspect ratio, density of state, spatial density and the growth methods. A higher and stable voltage signal was generated by the vapor-liquid-solid (VLS) grown samples compared to the aqueous chemical growth (ACG) grown samples. The finite element (FE) method was also used to calculate the expected output voltage signal from ZnO nanogenerator with different aspect ratio. From the FE results we found that the output voltage of the nanogenerator was decreased above an aspect ratio of 80 for ZnO nanowires.

Ions irradiation effects were investigated using ZnO nanowires grown by the ACG method on Si substrate. Iodine and argon ions of energy 40 MeV and 30 keV were used using fluencies of 3 ×1016 ions/cm2, and 1.3 ×1013 ions/cm2, respectively. The results show that heavy and high energy irradiation modifies the morphology, crystalline structure and optical properties of ZnO nanowires.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2010. 104 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1326
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-65405 (URN)978-91-7393-361-2 (ISBN)
Public defence
2010-08-27, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:15 (English)
Opponent
Supervisors
Available from: 2011-02-07 Created: 2011-02-07 Last updated: 2014-01-15Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Muhammad, RiazChen, ShulaChen, MiaoxiangJensen, JensNour, OmerWillander, Magnus

Search in DiVA

By author/editor
Muhammad, RiazChen, ShulaChen, MiaoxiangJensen, JensNour, OmerWillander, Magnus
By organisation
Department of Science and TechnologyThe Institute of TechnologyDepartment of Physics, Chemistry and Biology
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 109 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf