Highly spatially resolved structural and optical investigation of Bi nanoparticles in Y-Er disilicate thin films

Journal Article · Mon Aug 08 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4960644· OSTI ID:22594343

Scarangella, A. ^[1]; Amiard, G.; Miritello, M. ^[1]; Reitano, R. ^[2]; Priolo, F. ^[1]

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1. CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy)
2. Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy)

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 O{sub 2} or N{sub 2} 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 N{sub 2} environment, being strongly detrimental for the Er emission. A different scenario was instead observed in O{sub 2}, 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.

• OSTI ID: 22594343
• Journal Information: Applied Physics Letters, Vol. 109, Issue 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH
CROSS SECTIONS
EFFICIENCY
ENERGY-LOSS SPECTROSCOPY
ERBIUM COMPOUNDS
ERBIUM IONS
EXCITATION
HEAT TREATMENTS
MAGNETRONS
NANOPARTICLES
NANOSTRUCTURES
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
PRECIPITATION
SENSITIZERS
SILICON
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
YTTRIUM SILICATES