Correlation Between Optoelectronic and Positron Lifetime Properties in As-received and Plasma-treated ZnO Nanopowders

Peters, Raul; Paramo, J. Antonio; Quarles, C.A.; Strzhemechny, Y. M.

doi:10.1063/1.3120204

Cited by 2 publications

(2 citation statements)

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“…An additional corroboration for the presence of the ZnO phase in the material is a shift in the position of the deep defect band from 2.4 eV to 2.2 eV occurring at both temperatures with the decreasing dimensionality of the nanostructures. A very similar shift (2.4 eV to 2.2 eV) of the deep defect emission was observed in PL spectra of ZnO nanopowders with the decrease of an average grain size [36,37]. It should be noted that an unambiguous assignment of the optical transitions to specific defects in ZnO is still under debate.…”

Section: Resultssupporting

confidence: 70%

Correlation of Defect‐Related Optoelectronic Properties in Zn5(OH)6(CO3)2/ZnO Nanostructures with Their Quasi‐Fractal Dimensionality

Paramo

Strzhemechny

Endo

et al. 2015

Journal of Nanomaterials

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Hydrozincite (Zn5(OH)6(CO3)2) is, among others, a popular precursor used to synthesize nanoscale ZnO with complex morphologies. For many existing and potential applications utilizing nanostructures, performance is determined by the surface and subsurface properties. Current understanding of the relationship between the morphology and the defect properties of nanocrystalline ZnO and hydrozincite systems is still incomplete. Specifically, for the latter nanomaterial the structure-property correlations are largely unreported in the literature despite the extensive use of hydrozincite in the synthesis applications. In our work, we addressed this issue by studying precipitated nanostructures of Zn5(OH)6(CO3)2with varying quasi-fractal dimensionalities containing relatively small amounts of a ZnO phase. Crystal morphology of the samples was accurately controlled by the growth time. We observed a strong correlation between the morphology of the samples and their optoelectronic properties. Our results indicate that a substantial increase of the free surface in the nanocrystal samples generates higher relative concentration of defects, consistent with the model of defect-rich surface and subsurface layers.

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Section: Resultssupporting

confidence: 70%

Correlation of Defect‐Related Optoelectronic Properties in Zn5(OH)6(CO3)2/ZnO Nanostructures with Their Quasi‐Fractal Dimensionality

Paramo

Strzhemechny

Endo

et al. 2015

Journal of Nanomaterials

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“…Positron annihilation lifetime spectroscopy (PALS) was used to study the microporosity of polymers and polymeric blends/composites [3][4][5][6][7]. PALS is particularly useful as a qualitative tool for measuring the effect of processes on the porosity in materials.…”

Section: Introductionmentioning

confidence: 99%

A study of porosity of synthetic polymer nanoparticles using PALS

Pham¹,

Guagliardo²,

Williams³

et al. 2011

J. Phys.: Conf. Ser.

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Positron annihilation lifetime spectroscopy (PALS) has been used to study the free volume in dry synthetic polymer nanoparticles of various sizes. A series of poly(styrene/divinyl benzene) particles with diameters in the range of 100 to 500 nm were synthesized and then carefully chemically treated using the sulfonation process, to increase their porosity. The particles were characterised by Scanning Electron Microscopy (SEM), light scattering and PALS. Light scattering gave larger size for the treated particles, reflecting the hydration effect and therefore the increase in porosity. PALS spectra of untreated and treated particles gave four and three life-time components, respectively. Analysis by PAScual version 1.3.0 program indicated there was a reduction in the intensity and the type of the micropores in the treated particles. The data suggest PALS is a sensitive tool for detecting changes in microporosity in particles. The conflicting results obtained for light scattering compared to PALS for chemically treated particles is difficult to resolve and suggests sample preparation of polymeric materials for PALS is the critical factor.

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Correlation Between Optoelectronic and Positron Lifetime Properties in As-received and Plasma-treated ZnO Nanopowders

Cited by 2 publications

References 0 publications

Correlation of Defect‐Related Optoelectronic Properties in Zn5(OH)6(CO3)2/ZnO Nanostructures with Their Quasi‐Fractal Dimensionality

Correlation of Defect‐Related Optoelectronic Properties in Zn5(OH)6(CO3)2/ZnO Nanostructures with Their Quasi‐Fractal Dimensionality

A study of porosity of synthetic polymer nanoparticles using PALS

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