Beam Plasma Characteristics of a Helicon Plasma Source Measured by a Spatially Resolved Optical Emission Spectroscope

AbstractThis paper reviews of some of the progress made in the development of ZnO-based light emitting diodes (LEDs). n-ZnO/p-AlGaN-based heterostructures have been successfully for the fabrication of UV emitting LEDs that have operated at temperatures up to 650K, suggesting an excitonic origin for the optical transitions. RF-plasma-assisted molecular beam epitaxy has been used to grow epitaxial CdxZn1-xO films on GaN/sapphire structure. These films have a single-crystal wurtzite structure as demonstrated by structural and compositional analysis. High quality CdxZn1-xO films were grown with up to x=0.78 mole fraction as determined by RBS and SIMS techniques. Optical emission ranging from purple (Cd0.05Zn0.95O) to yellow (Cd0.29Zn0.71O) was observed. Compositional fluctuations in a Cd0.16Zn0.84O films were not detected by spatially resolved CL measurements, although intensity fluctuation with features of ∼0.5 μm diameter were seen on the intensity maps. Time resolved photoluminescence shows multi-exponential decay with 21 psec. and 49±3 psec. lifetimes, suggesting that composition micro-fluctuations may be present in Cd0.16Zn0.84O film.

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Merits of microwave plasmas for optical emission spectrometry – characterization of an axially viewed microwave-sustained, inductively coupled, atmospheric-pressure plasma (MICAP)

Journal of Analytical Atomic Spectrometry ◽

10.1039/d0ja00293c ◽

2020 ◽

Vol 35 (10) ◽

pp. 2369-2377

Author(s):

Helmar Wiltsche ◽

Matthias Wolfgang

Keyword(s):

Atmospheric Pressure ◽

Atmospheric Pressure Plasma ◽

Optical Emission ◽

Plasma Source ◽

Optical Emission Spectrometry ◽

Emission Spectrometry ◽

Icp Oes ◽

Microwave Plasmas ◽

Inductively Coupled

The MICAP is a microwave driven plasma source employing nitrogen as the plasma gas. In this work we compare LODs and LOQs obtained in axial viewing with those obtained by ICP-OES and evaluate the effect of air instead of nitrogen as the plasma gas.

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Relevance for food sciences of quantitative spatially resolved element profile investigations in wheat ( Triticum aestivum ) grain

Journal of The Royal Society Interface ◽

10.1098/rsif.2013.0296 ◽

2013 ◽

Vol 10 (84) ◽

pp. 20130296 ◽

Cited By ~ 23

Author(s):

Paula Pongrac ◽

Ivan Kreft ◽

Katarina Vogel-Mikuš ◽

Marjana Regvar ◽

Mateja Germ ◽

...

Keyword(s):

Triticum Aestivum ◽

Inductively Coupled Plasma ◽

Optical Emission ◽

Tissue Level ◽

Emission Spectrometry ◽

Bulk Analysis ◽

Inductively Coupled ◽

Element Concentrations ◽

Spatially Resolved ◽

Soil Zn

Bulk element concentrations of whole grain and element spatial distributions at the tissue level were investigated in wheat ( Triticum aestivum ) grain grown in Zn-enriched soil. Inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry were used for bulk analysis, whereas micro-proton-induced X-ray emission was used to resolve the two-dimensional localization of the elements. Soil Zn application did not significantly affect the grain yield, but did significantly increase the grain Ca, Fe and Zn concentrations, and decrease the grain Na, P and Mo concentrations; bulk Mg, S, K, Mn, Cu, Cd and Pb concentrations remained unchanged. These changes observed in bulk element concentrations are the reflection of tissue-specific variations within the grain, revealing that Zn application to soil can lead to considerable alterations in the element distributions within the grain, which might ultimately influence the quality of the milling fractions. Spatially resolved investigations into the partitioning of the element concentrations identified the tissues with the highest element concentrations, which is of utmost importance for accurate prediction of element losses during the grain milling and polishing processes.

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