Growth of ZnO nanostructures on Au-coated Si: Influence of growth temperature on growth mechanism and morphology

Kumar, R. Senthil; McGlynn, Enda; Biswas, Mahua; Saunders, Ruth B.; Trolliard, Gilles; Soulestin, Bernard; Duclère, J.-R.; Mosnier, Jean-Paul; Henry, M.O.

doi:10.1063/1.2996279

Cited by 31 publications

(21 citation statements)

References 39 publications

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“…These methods contain pulsed laser deposition [18], rf magnetron sputtering [19], spray pyrolysis [20], sol-gel [21] and vapor phase transport method (VPT) [22]. Within all these methods, VPT method is considerably used due to the simple and low-cost equipment and has been utilized to grow ZnO nanostructures of diverse morphology with excellent crystalline and optical quality [23]. To our knowledge, there are not many studies on ZnO:Mn nanorods grown by VPT method.…”

Section: Introductionmentioning

confidence: 99%

Defect-mediated ferromagnetism in ZnO:Mn nanorods

et al. 2013

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In this work, the structural, chemical and magnetic properties of ZnO:Mn nanorods were investigated. Firstly, well-aligned ZnO nanorods with their long axis parallel to the crystalline c-axis were successfully grown by the vapor phase transport technique on Si substrates coated with a ZnO buffer layer. Mn metal was then diffused into these nanorods at different temperatures in vacuum. From SEM results, ZnO:Mn nanorods were observed to have diameters of ~100 nm and lengths of 4 µm. XPS analysis showed that the Mn dopant substituted into the ZnO matrix with a valence state of +2. Magnetic measurements performed at room temperature revealed that undoped ZnO nanorods exhibit ferromagnetic behavior which may be related to oxygen vacancy defect-mediated d 0 ferromagnetism. ZnO:Mn samples were seen to show an excess room temperature ferromagnetism that is attributed to the presence of oxygen vacancy defects forming bound magnetic polarons involving Mn.

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Section: Introductionmentioning

confidence: 99%

Defect-mediated ferromagnetism in ZnO:Mn nanorods

et al. 2013

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“…[1][2][3][4][5] Because of this sensitivity and morphological diversity, in order to reproducibly grow specific ZnO nanostructure morphologies, especially on an industrial scale, a greater theoretical understanding of the growth process is required. There is presently a scarcity of theoretical work on ZnO nanostructure growth, when compared to the number of observational reports of various ZnO morphologies.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Analysis of Nucleation and Growth of ZnO Nanostructures in Vapor Phase Transport Growth

Saunders

McGlynn

Henry

2011

Crystal Growth & Design

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This paper discusses the growth atmosphere, condensing species and nucleation conditions relevant to vapour phase transport growth of ZnO nanostructures, including the molecular parameters and thermodynamics of the gas phase ZnO molecule and its importance compared to atomic Zn and molecular O 2 . The partial pressure of molecular ZnO in a Zn/O 2 mix at normal ZnO growth temperatures is ∼ 6 × 10 −7 of the Zn partial pressures. In typical vapour phase transport growth conditions, using carbothermal reduction, the Zn vapour is always undersaturated while the ZnO vapour is always supersaturated. In the case of the ZnO vapour, our analysis suggests that the barrier to homogeneous nucleation (or heterogeneous nucleation at unseeded/uncatalysed areas of the substrates) is too large for nucleation of this species to take place, which is consistent with experimental evidence that nanostructures will not grow on unseeded areas of substrates. In the presence of suitable accommodation sites, due to ZnO seeds, growth can occur via Zn vapour condensation (followed by oxidation) and via direct condensation of molecular ZnO (whose flux at the surface, although less than that of Zn vapour, is still sufficient to yield an appreciable nanostructure deposit). The balance between these two

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“…This boat was then loaded into the furnace for the nanorod growth. Further details concerning the growth process are reported elsewhere [5,6,15].…”

Section: Vpt Nanorod Growthmentioning

confidence: 99%

Origin of the 3.331 eV emission in ZnO nanorods: Comparison of vapour phase transport and pulsed laser deposition grown nanorods

Inguva

Gray

McGlynn

et al. 2016

Journal of Luminescence

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*Corresponding authors: saikumar.inguva2@mail.dcu.ie and enda.mcglynn@dcu.ie. KEYWORDSZnO seed layers, vertically aligned ZnO nanorods, vapour phase transport, pulsed laser deposition, 3.331 eV emission. 2 ABSTRACTIn this work, we report the growth of vertically aligned ZnO nanorods with excellent optical quality by both catalyst free vapor phase transport (VPT) and catalyst free pulsed laser deposition (PLD). We compare the near band edge emission of such deposits, with a focus on the identification of the origin of the 3.331 eV emission feature. X-ray diffraction (XRD), scanning electron microscopy (SEM) and low-temperature (13 K) photoluminescence (PL) were used to characterise these nanorod deposits. XRD and SEM data reveal that both techniques lead to highly textured ZnO nanorod arrays with uniform c-axis orientation normal to the substrate surface. The VPT-grown nanorods are well separated and show smooth, facetted surfaces whereas the PLD-grown nanorods are more closely packed and display comparatively rougher surfaces. The optical quality of the samples obtained by both growth methods was very good and low-temperature PL spectra were dominated in both cases by a strong I 6 bound exciton (BX) emission (3.36 eV), and also showed emission from the surface exciton and the free exciton. A comparatively weak visible emission was also observed in samples deposited by both techniques.The main difference between the PLD-and VPT-grown nanorod samples is the presence of the 3.331 eV emission in the former, and its complete absence in the latter (as well as in continuous PLD-grown seed layers) which is discussed in light of the differing surface morphologies mentioned above and which provides strong support for our previous assignment of the origin of this defect to structural defects in the inhomogeneous sub-surface region close to the rough nanorod surface.3

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Growth of ZnO nanostructures on Au-coated Si: Influence of growth temperature on growth mechanism and morphology

Cited by 31 publications

References 39 publications

Defect-mediated ferromagnetism in ZnO:Mn nanorods

Defect-mediated ferromagnetism in ZnO:Mn nanorods

Theoretical Analysis of Nucleation and Growth of ZnO Nanostructures in Vapor Phase Transport Growth

Origin of the 3.331 eV emission in ZnO nanorods: Comparison of vapour phase transport and pulsed laser deposition grown nanorods

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