| AVS 54th International Symposium | |
| Nanometer-scale Science and Technology | Thursday Sessions |
| Session NS-ThM |
| Session: | Nanotube Devices and Processes |
| Presenter: | Y. Mao, University of California at Los Angeles |
| Authors: | Y. Mao, University of California at Los Angeles J.P. Chang, University of California at Los Angeles |
| Correspondent: | Click to Email |
Yttria is one promising hosting material for rare-earth-ion-activated phosphors with applications including amplifiers, lasers, waveguides, X-ray imaging, bioimaging, and displays due to their luminescent characteristics and stability in high vacuum. In fact, in our most recent study, we have deposited Er-doped Y2O3 thin films by radical-enhanced atomic layer deposition (ALD)1 and demonstrated that the Er incorporated in Y2O3 can reach a concentration as high as 1021 cm-3 with outstanding room temperature photoluminescence (PL) at 1.54 µm in thin Er-doped (6-14 at. %) Y2O3 films deposited at 350°C.2 Meanwhile, nanomaterials exhibit physical properties, in particular, increased luminescence efficiency, which are not observed with their bulk counterparts. Hence, in this talk, we present our recent work on the synthesis of nanotubes of rare-earth (RE, Er and Yb) doped Y2O3, by a solution synthetic method. The processing temperature, pH, time, addition rate of NaOH, the concentration of precursors, and the annealing temperature dictated the nucleation/growth of RE doped Y(OH)3 nanotubes. These tubes were converted to RE doped yttria by high temperature annealing and the resulting nanotubes had varying RE dopant concentrations (0-100%) with sizes ranging from 40-500 nm in diameter and 2-10 µm in length. X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microsecopy (HRTEM), selected area electron diffraction (SAED), and extended x-ray absorption fine structure (EXAFS) were combined to delineate the structure and composition of these nanotubes. The erbium coordination number and local bonding environment are assessed by synchrotron based EXAFS analysis, and are shown to dictate the measured photoluminescence intensity.3 Their room luminescent properties (PL and catholuminescence, CL) are outstanding and even superior than the thin films synthesized by ALD. Finally, we will discuss their electronic properties and the application of these doped yttria nanostructures as small and compact planar optical amplifier.
1T.T. Van and J.P. Chang, Appl Phys Lett, 87, 011907 (2005).
2T.T. Van, J. Hoang, R. Ostroumov, K. L. Wang, J. R. Bargar, J. Lu, H.-O. Blom, and J.P. Chang, J Appl Phys, 100, 073512 (2006).
3T.T. Van, J. R. Bargar, and J.P. Chang, J Appl Phys, 100, 023115 (2006).