Influence of Co doping content on its valence state in Zn1−xCoxO (0≤x≤0.15) thin films

Wei, Ling; Li, Zonghui; Zhang, W.F.

doi:10.1016/j.apsusc.2008.12.064

Cited by 49 publications

(24 citation statements)

References 20 publications

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“…These increase from 3.30 eV for undoped ZnO to ~3.43 eV for ZC1 and appear to saturate at ~3.47/8 eV for ZC2-ZC4. This increase in band gap with increasing Co doping is in contrast to the decrease found in Co-doped ZnO films prepared by sol-gel [16] and hydrothermal [30] techniques, although in both cases the doping extended to higher levels than in this study. By contrast, but in common with the data presented here, an increase of band gap has been reported with increased concentration for the cases of Co [19,31] and Ga [32] dopants.…”

Section: Optical Absorptioncontrasting

confidence: 98%

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Solution-based synthesis of cobalt-doped ZnO thin films

et al. 2012

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Publisher rights This is the author's version of a work that was accepted for publication in Thin Solid Films. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Thin Solid Films, Vol. 524, 01/12/2012 General rights Copyright for the publications made accessible via the Queen's University Belfast Research Portal is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights.Take down policy The Research Portal is Queen's institutional repository that provides access to Queen's research output. Every effort has been made to ensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws. If you discover content in the Research Portal that you believe breaches copyright or violates any law, please contact openaccess@qub.ac.uk. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT1 Solution-based synthesis of cobalt-doped ZnO thin films Sesha VempatiSchool of Mathematics and Physics, Queen's University Belfast, BT7 1NN, UK, Amitha ShettyMaterials Research Center, Indian Institute of Science, Bangalore -560012, India. P. Dawson*School of Mathematics and Physics, Queen's University Belfast, BT7 1NN, UK, K. K. Nanda and S.B. KrupanidhiMaterials Research Center, Indian Institute of Science, Bangalore -560012, India.Corresponding author: p.dawson@qub.ac.uk AbstractUndoped and cobalt-doped (1-4 wt%) ZnO polycrystalline, thin films have been fabricated on quartz substrates using sequential spin-casting and annealing of simple salt solutions. X-ray diffraction (XRD) reveals a wurzite ZnO crystalline structure with high-resolution transmission electron microscopy showing lattice planes of separation 0.26 nm, characteristic of (002) planes.The Co appears to be tetrahedrally co-ordinated in the lattice on the Zn sites (XRD) and has a charge of +2 in a high-spin electronic state (X-ray photoelectron spectroscopy). Co-doping does not alter the wurzite structure and there is no evidence of the precipitation of cobalt oxide phases within the limits of detection of Raman and XRD analysis. Lattice defects and chemisorbed oxygen are probed using photoluminescence and Raman spectroscopy -crucially, however, this transparent semiconduc...

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Section: Optical Absorptioncontrasting

confidence: 98%

“…3 prepared; this method has been employed to prepare thin films of Co-doped ZnO [16]. In the work reported here, however, we have adopted an even more direct methodology based on decomposition of metal salts via oxidation at high temperature.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Solution-based synthesis of cobalt-doped ZnO thin films

et al. 2012

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“…On the other side, a similar trend of decrease of band edge in Zn 1-x Co x O films is reported by many workers [5,17,19]. This low energy shift of the E g as a function of the Co content can be explained due to the s,p-d exchange interactions between the band electrons and the localized d electrons of the Co 2+ ions substituting for Zn 2+ ions [20,21]. The s-p and p-d exchange interactions give rise to a negative and a positive correction to the conduction and valence-band edges, leading to narrowing of the band gap [22].…”

Section: Transmittancesupporting

confidence: 85%

Structural and optical properties of Co and Ni doped ZnO thin films prepared by RF magnetron sputtering

Stolyarchuk

Kleto

Dziedzic

2017

PCSS

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We have reported the effect of Co and Ni doping on structural and optical properties of ZnO thin films prepared by RF reactive sputtering technique. The composite targets were formed by mixing and pressing of ZnO, Mn 3 O 4 , CoO and NiO powders. The thin films were deposited on sapphire, quartz and glass substrates. The structure study confirms the formation of the hexagonal wurtzite ZnO without any secondary phase in transition metal (Co, Ni) -doped samples. Cross-sectional TEM images of all studied samples show a denseand uniformly textured structure composed of column-like structure along the growth direction. The surface morphology of the thin films was studied using atomic force microscopy (AFM). Different surface morphology (AFM) images were obtained depending on the film composition and growth conditions. Optical absorption spectra suggest of substitution Zn 2+ ions in ZnO lattice by transition metal atoms. The shift of the absorption edge due to decrease the energy band gap with increasing cobalt content and complex dependence of the energy band gap on content of nickel was observed in optical absorption spectra of the studied films. The room temperature photoluminescence peaks are attributed to near band gap emission and vacancy or defect states.

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“…Figure 2 shows the X-ray photoelectron spectroscopy (XPS) core level spectra of Fe 2p and Mn 2p in BFMO and BFO/BMO, calibrated by the C 1s line (284.8 eV) binding energy22. The binding energy of Fe 2p 3/2 is at 710.3 eV for BFMO and 710.1 eV for BFO/BMO.…”

Section: Resultsmentioning

confidence: 99%

Magnetic interactions in BiFe0.5Mn0.5O3 films and BiFeO3/BiMnO3 superlattices

Sheng

Khalid

et al. 2015

Sci Rep

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The clear understanding of exchange interactions between magnetic ions in substituted BiFeO3 is the prerequisite for the comprehensive studies on magnetic properties. BiFe0.5Mn0.5O3 films and BiFeO3/BiMnO3 superlattices have been fabricated by pulsed laser deposition on (001) SrTiO3 substrates. Using piezoresponse force microscopy (PFM), the ferroelectricity at room temperature has been inferred from the observation of PFM hysteresis loops and electrical writing of ferroelectric domains for both samples. Spin glass behavior has been observed in both samples by temperature dependent magnetization curves and decay of thermo-remnant magnetization with time. The magnetic ordering has been studied by X-ray magnetic circular dichroism measurements, and Fe-O-Mn interaction has been confirmed to be antiferromagnetic (AF). The observed spin glass in BiFe0.5Mn0.5O3 films has been attributed to cluster spin glass due to Mn-rich ferromagnetic (FM) clusters in AF matrix, while spin glass in BiFeO3/BiMnO3 superlattices is due to competition between AF Fe-O-Fe, AF Fe-O-Mn and FM Mn-O-Mn interactions in the well ordered square lattice with two Fe ions in BiFeO3 layer and two Mn ions in BiMnO3 layer at interfaces.

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Influence of Co doping content on its valence state in Zn1−xCoxO (0≤x≤0.15) thin films

Cited by 49 publications

References 20 publications

Solution-based synthesis of cobalt-doped ZnO thin films

Solution-based synthesis of cobalt-doped ZnO thin films

Structural and optical properties of Co and Ni doped ZnO thin films prepared by RF magnetron sputtering

Magnetic interactions in BiFe0.5Mn0.5O3 films and BiFeO3/BiMnO3 superlattices

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