Highly spatially resolved structural and optical investigation of Bi nanoparticles in Y-Er disilicate thin films
| Autor: | R. Reitano, Maria Miritello, Francesco Priolo, Adriana Scarangella, Guillaume Amiard, Simona Boninelli |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Photoluminescence Materials science SPECTROSCOPY Physics and Astronomy (miscellaneous) Silicon Analytical chemistry Nanoparticle chemistry.chemical_element 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Erbium chemistry 0103 physical sciences Scanning transmission electron microscopy Energy filtered transmission electron microscopy Photoluminescence excitation Thin film 0210 nano-technology PHOTONICS ENERGY-TRANSFER |
| Popis: | Er-containing silicon compatible materials have been widely used as infrared emitters for microphotonics application. In this field, the additional introduction of a proper sensitizer permits to increase the Er excitation cross sections, thus increasing its optical efficiency. This work aims to investigate the influence of a post-transition metal, bismuth, on the optical properties of erbium-yttrium disilicate thin films synthesized by magnetron co-sputtering. After thermal treatments at 1000 °C in O2 or N2 environment, the presence of small precipitates, about 6 nm in diameter, was evidenced by transmission electron microscopy analyses. The spatially resolved chemical nature of the nanoparticles was discerned in the Si and O rich environments by means of scanning transmission electron microscopy–energy dispersive X-ray and scanning transmission electron microscopy–electron energy loss spectroscopy analyses performed with nanometric resolution. In particular, metallic Bi nanoparticles were stabilized in the N2 environment, being strongly detrimental for the Er emission. A different scenario was instead observed in O2, where the formation of Bi silicate nanoparticles was demonstrated with the support of photoluminescence excitation spectroscopy. In particular, a broad band peaked at 255 nm, correlated to the excitation band of Bi silicate nanoparticles, was identified in Er excitation spectrum. Thus Bi silicate clusters act as sensitizer for Er ions, permitting to improve Er emission up to 250 times with respect to the resonant condition. Moreover, the Er decay time increases in the presence of the Bi silicate nanoparticles that act as cages for Er ions. These last results permit to further increase Er optical efficiency in the infrared range, suggesting (Bi + Er)-Y disilicate as a good candidate for applications in microphotonics. |
| Databáze: | OpenAIRE |
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