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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optical and luminescence properties of erbium, ytterbium and terbium doped in aluminum nitride

Corn, Tyler R. 24 July 2010 (has links)
Studies have been done to determine rare-earth elements’ optical and luminescent properties using wide bandgap nitride semiconductors as suitable hosts. Research done here will contribute to the information needed to further study rare-earth elements and their unique properties. Thin films of rare-earth elements erbium, terbium, ytterbium, and both erbium and ytterbium doped into AlN are studied by laser excitation. A 532 nm Nd: YAG green laser and 783nm crystal infrared laser are used for excitation in conjunction with a spectrometer to measure photoluminescence. With the 532 nm laser, AlN: Er emits peaks at 554 nm, 561 nm, and 1552 nm, AlN: Tb emits peaks at 549 nm and 562 nm, AlN: Yb emits peaks at 966 nm, and co-doped AlN: ErYb contains peaks including both AlN: Er and AlN: Yb. Energy transfer occurred from Er to Yb resulting in an increased magnitude and peak shift. The 783 nm laser gave peaks at 1563nm for AlN: Er, 1508 nm and 1533 nm for AlN: Tb, and 1567nm for AlN: ErYb. No detectable peaks were given for AlN: Yb. A peak shift was detected in comparison of AlN: Er and AlN: ErYb. A magnetic field of 1000 G was applied to AlN: ErYb resulting in an increase in intensity of the major peak at 561nm with a splitting, creating a secondary peak at 564.5 nm. Biomedical applications can be used from the high penetration ability of lower wavelength lasers and the use of a magnetic field, which is not harmful to the human body. Enhanced green emission in erbium can be useful in future optical, photonic, and electrical devices. / Department of Physics and Astronomy
2

Visible and infrared emission from Er₂O₃ nanoparticles, and Ho⁺³, Tm⁺³, and Sm⁺³ doped in AlN for optical and biomedical applications

Wilkinson, Lynda L. 21 July 2012 (has links)
Rare-earth ions holmium (Ho+3), Thulium (Tm+3), and Samarium (Sm+3) were investigated for infrared emission and their possible biomedical applications by a photoluminescence (PL) system. Holmium’s (Ho+3) emission peaks were the result of transitions 5 S2 → 5 I7, and 5 S2 → 5 I5 respectively. Samarium’s (Sm+3) emission peaks were 936 nm and 1863 nm. Thulium’s (Tm+3) emission peaks were the a result of transitions 3 H4 → 3 H6, 3 H5 → 3 H6 , and 3 F4 → 3 H6 respectively. Erbium Oxide nanoparticles (Er2O3) mixed with water by a photoluminescence (PL) system. Erbium Oxide’ (Er2O3) nanoparticle’s emission peaks were the a result of transitions 4 I15/2 → 4 S3/2 , 4 I15/2 → 4 I13/2 respectively. The process was also repeated in vacuum and it was found that the green emission enhances tremendously when the nanoparticles are excited in vacuum. This enhanced luminescence from the Erbium Oxide nanoparticles shows their potential importance in the optical devices and Biomedical applications. / Department of Physics and Astronomy

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