0000000000737189
AUTHOR
Ivita Bite
Sensing properties of assembled Bi2S3nanowire arrays
Bismuth sulfide (Bi2S3) nanowires were grown in porous aluminium oxide template and a selective chemical etching was applied to transfer the nanowires to a solution. Well aligned nanowire arrays were assembled on pre-patterned silicon substrates employing dielectrophoresis. Electron beam lithography was used to connect aligned individual nanowires to the common macroelectrode. In order to evaluate the conductometric sensing performance of the Bi2S3 nanowires, current–voltage characteristics were measured at different relative humidity (RH) levels (5–80%) / argon medium. The response of the Bi2S3 nanowires depending of RH is found to be considerably different from those reported for other ty…
Gallium Concentration Optimisation of Gallium Doped Zinc Oxide for Improvement of Optical Properties
The research has been supported by project ERA.NET RUS_ST2017-05 (Latvia) and No. 18-52-76002 (Russia). The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union’s Hori-zon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-Teaming-Phase2 under grant agreement No. 739508, project CAMART².
Novel method of phosphorescent strontium aluminate coating preparation on aluminum
This work was supported by the ERDF , European-Union Project No. 1.1.1.1/16/A/182 .
The boron effect on low temperature luminescence of SrAl2O4:Eu, Dy
V.V. acknowledges the financial support of ERDF PostDoc project No. 1.1.1.2/VIAA/3/19/440 (University of Latvia Institute of Solid State Physics, Latvia) and K.S., I.B., A.Z., D.M. and K.L. acknowledge the financial support of ERDF, European-Union Project No. 1.1.1.1/16/A/182 (University of Latvia Institute of Solid State Physics, Latvia).
Electronic processes in doped ZnO nanopowders
The financial support of research grants ERA.NET RUS_ST20170-051 and SFERA II project “Transnational Access activities” (EU 7th Framework Programme Grant Agreement N312643). This work was partly supported by the Russian Foundation for Basic Research, project no. 18-52-76002.
The search for defects in undoped SrAl2O4 material
This research project was supported financially by ERDF Project No: Nr.1.1.1.1/16/A/182 .
Low temperature afterglow from SrAl 2 O 4 : Eu, Dy, B containing glass
V.V. acknowledges the financial support of ERDF PostDoc project No. 1.1.1.2/VIAA/3/19/440 (University of Latvia Institute of Solid State Physics, Latvia) and LP the Academy of Finland (Flagship Programme, Photonics Research and Innovation PREIN 320165 and Academy Project -326418) for the financial support. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01- 2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART 2 .
Low Temperature Afterglow from SrAl <sub>2</sub>O <sub>4</sub>: EU, Dy, B Containing Glass
SrAl2O4: Eu, Dy, B particles were added in a phosphate glass (90NaPO3-10NaF (in mol%)) using the direct doping method. For the first time, the composition of the particles prior to and after embedding them in the glass was analysed using EPMA analysis. Boron was found to be incorporated in already distorted surroundings creating new trapping centers in the particles which are thought to be favourable for the tunnelling process and so for the afterglow at 10K. Despite the partial decomposition of the particles, the glass exhibit afterglow at low temperature confirming to be promising materials for low temperature applications.
Thermostimulated luminescence of plasma electrolytic oxidation coatings on 6082 aluminium surface
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2016/12 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Authors are grateful to R. Ignatans for measurements and analysis of XRD spectra and ElGoo Tech ltd. for providing PEO equipment.
Morphological and optical property study of Li doped ZnO produced by microwave-assisted solvothermal synthesis
Abstract ZnO materials have been at the centre of many studies for decades. Doping of ZnO by lithium atoms is a prospective approach for compensation of n-type conductivity in the unintentionally doped ZnO aimed at obtaining p-type semiconductor. In this study, we have synthesized ZnO rod-like powders doped with lithium ions (0–0.65 atom%) by the new microwave-assisted solvothermal method in order to obtain greater photoluminescence intensity of ZnO emissions in the UV region. The obtained powders contain nanoparticles from 20 nm up to 250 nm depending on Li content. X-ray diffractometry and Raman spectroscopy were employed to characterise the structure of ZnO powders, scanning electron mic…
Re-Evaluation of Chromium Doped Alumina for Dosimetric Applications
Financial support provided by Scientific Research “Luminescence Mechanisms and Dosimeter Properties in Prospective Nitrides and Oxides Using TL and OSL Methods” LZP FLPP No. LZP-2018/1-0361 implemented at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART².
Sub-nanosecond excitonic luminescence in ZnO:In nanocrystals
The financial support of research European Union ERA.NET RUS_ST20170-51 . This work was partly supported by Russian Foundation for Basic Research, Russia , project No. 18-52-76002 . The sample preparation was carried out as part of SFERA II project -Transnational Access activities ( European Union 7th Framework Programme Grant Agreement N3126430 ).
Pretestības un tranzistoru pusvadītāju nanovadu sensoru izveide gāzveida vielu analīzei
Pretestības un tranzistoru pusvadītāju nanovadu sensoru izveide gāzveida vielu analīzei. Bite I., darba vadītājs Dr. Chem. Erts D. Bakalaura darbs, 44 lapas, 25 attēli, 1 tabulas, 41 literatūras avoti. Latviešu valodā. Darbā pētīti Bi2S3 nanovadi, kuru rādiuss ir 40 nm, kā arī Ge nanovadu elektrovadītspējas izmaiņas dažādos relatīvajos mitrumos un to izmantošanas iespējas sensoru veidošanā. Parādīts, ka atkarībā no relatīvā mitruma Bi2S3 nanovadiem n-tipa vadāmība var mainīties uz p-tipu un otrādi, kura varētu būt saistīta ar lādiņesēju līdzsvara koncentrācijām. Literatūras apskatā ir apkopota informācija par: nanovadu iegūšanas metodēm; nanovadu sensoru raksturlielumiem; nanovadu sensoru i…
Formation of translucent nanostructured zirconia ceramics
Abstract In this work the mechanisms that affect the optical transparency of nanostructured translucent ZrO2 ceramics are studied. The translucent ceramic samples were obtained from a low agglomeration nanosized powder at low pressure and low temperature sintering. Even low pressures cause structural changes and defect creation in the nanocrystals. Annealing was used to study the grain formation, structure and impact of defects. Significant changes in translucency were observed with increase in pore size. In order to further understand the defect creation, the obtained ceramics were doped with Er3+ ions and studied optically. Photoluminescence studies revealed a change in the ratio of green…
Recent progress in understanding the persistent luminescence in SrAl2O4:Eu,Dy
This work was conducted with the funding of Scientific Research Project for Students and Young Researchers realised at the Institute of Solid State Physics, University of Latvia [SJZ/2018/2].
Recent progress in understanding the persistent luminescence in SrAl 2 O 4 :Eu,Dy
Ever since the discovery of SrAl2O4:Eu,Dy persistent afterglow material, that can intensively glow up to 20 h, the mechanism of long-lasting luminescence has been a popular area of research. The re...
Optical Absorption of Excimer Laser‐Induced Dichlorine Monoxide in Silica Glass and Excitation of Singlet Oxygen Luminescence by Energy Transfer from Chlorine Molecules
An optical absorption (OA) band of interstitial dichlorine monoxide molecules with peak at 4.7 eV and halfwidth 0.94 eV is identified in F2 laser - irradiated (photon energy=7.9 eV) synthetic silica glass bearing both interstitial O2 and Cl2 molecules. Alongside with intrinsic defects, this OA band can contribute to solarization of silica glasses produced from SiCl4. While the formation of ClClO is confirmed by its Raman signature, its structural isomer ClOCl may also contribute to this induced OA band. Thermal destruction of this band between 300C and 400C almost completely restores the pre-irradiation concentration of interstitial Cl2. An additional weak OA band at 3.5 eV is tentatively a…
Jūras vides kvalitātes kritēriju un pārtikas risku robežvērtību izstrāde, pamatojoties uz metālisko elementu (Cd, Cu, Hg, Pb un Zn )uzkrāšanās tendencēm Baltijas jūras un Rīgas līča zivīs
Jūras vides kvalitātes kritēriju un pārtikas risku robežvērtību izstrāde, pamatojoties uz metālisko elementu (Hg, Cd, Pb, Cu un Zn) uzkrāšanās tendencēm Baltijas jūras un Rīgas līča zivīs. Bite I., zinātniskie vadītāji pētniece Dr. Chem. Poikāne R. un Prof., Dr. Chem. Vīksna A. Maģistra darbs, 88 lapas, 23 attēli, 17 tabulas, 120 literatūras avoti, 5 pielikumi. Latviešu valodā. Darbā tika kvantitatīvi noteikts dzīvsudraba, kadmija, svina, vara, cinka un lipīdu saturs apaļo jūras grunduļu, asaru, mencu, reņģu un plekstu muskuļaudos atkarībā no vecuma, izmantojot atomu absorbcijas spektrometrijas metodes un gravimetriju. Zivju vecums tika noteikts izmantojot optisko mikroskopu. Literatūras ap…
Niobium enhanced europium ion luminescence in hafnia nanocrystals
This work was supported by the UL ISSP grant for Scientific Research Projects for Students and Young Researchers SJZ/2016/15 .
Usability of Cr-Doped Alumina in Dosimetry
Dosimetry is a widespread material science field dealing with detection and quantification of ionizing radiation using electronic processes in materials. One of the main aspects that determines the performance of dosimeters is the type of defects the material contains. Crystalline lattice imperfections are formed around impurity ions, which may have a smaller or larger size, or different oxidation states compared to host ions. In this study, we show what effects Cr impurities have on the luminescent properties of alumina. Porous Al 2 O 3 : Cr microceramics synthesized using the sol-gel method showed a higher thermoluminescence response than a single crystal ruby. We have found that Cr 2 O 3…
Production of Phosphorescent Coatings on 6082 Aluminum Using Sr0.95Eu0.02Dy0.03Al2O4-δ Powder and Plasma Electrolytic Oxidation
In this study, a new approach for producing phosphorescent aluminum coatings was studied. Using the plasma electrolytic oxidation (PEO) process, a porous oxide coating was produced on the Al6082 aluminum alloy substrate. Afterwards, activated strontium aluminate (SrAl2O4: Eu2+, Dy3+) powder was filled into the cavities and pores of the PEO coating, which resulted in a surface that exhibits long-lasting luminescence. The structural and optical properties were studied using XRD, SEM, and photoluminescence measurements. It was found that the treatment time affects the morphology of the coating, which influences the amount of strontium aluminate powder that can be incorporated into the coating …
X-ray excited luminescence of SrAl2O4:Eu,Dy at low temperatures
This research project was supported financially by ERDF Project No 1.1.1.1/16/A/182.
Phase stability and oxygen-sensitive photoluminescence of ZrO2:Eu,Nb nanopowders
This work was supported by institutional research funding ( IUT34-27 and IUT2-14 ) of the Estonian Ministry of Education and Research .