Concentration dependence of the Er{sup 3+} visible and infrared luminescence in Y{sub 2-x}Er{sub x}O{sub 3} thin films on Si

Journal Article · Sat Aug 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3195077· OSTI ID:21361781

Lo Savio, R; Miritello, M ^[1]; Cardile, P; Priolo, F ^[1]

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1. MATIS CNR-INFM and Dipartimento di Fisica e Astronomia, Universita di Catania, Via Santa Sofia 64, 95123 Catania (Italy)

Y{sub 2-x}Er{sub x}O{sub 3} thin films, with x varying between 0 and 0.72, have been successfully grown on crystalline silicon (c-Si) substrates by radio-frequency magnetron cosputtering of Y{sub 2}O{sub 3} and Er{sub 2}O{sub 3} targets. As-deposited films are polycrystalline, showing the body-centered cubic structure of Y{sub 2}O{sub 3}, and show only a slight lattice parameter contraction when x is increased, owing to the insertion of Er ions. All the films exhibit intense Er-related optical emission at room temperature both in the visible and infrared regions. By studying the optical properties for different excitation conditions and for different Er contents, all the mechanisms (i.e., cross relaxations, up-conversions, and energy transfers to impurities) responsible for the photoluminescence (PL) emission have been identified, and the existence of two different well-defined Er concentration regimes has been demonstrated. In the low concentration regime (x up to 0.05, Er-doped regime), the visible PL emission reaches its highest intensity, owing to the influence of up-conversions, thus giving the possibility of using Y{sub 2-x}Er{sub x}O{sub 3} films as an up-converting layer in the rear of silicon solar cells. However, most of the excited Er ions populate the first two excited levels {sup 4}I{sub 11/2} and {sup 4}I{sub 13/2}, and above a certain excitation flux a population inversion condition between the former and the latter is achieved, opening the route for the realization of amplifiers at 2.75 mum. Instead, in the high concentration regime (Er-compound regime), an increase in the nonradiative decay rates is observed, owing to the occurrence of cross relaxations or energy transfers to impurities. As a consequence, the PL emission at 1.54 mum becomes the most intense, thus determining possible applications for Y{sub 2-x}Er{sub x}O{sub 3} as an infrared emitting material.

• OSTI ID: 21361781
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 4; Other Information: DOI: 10.1063/1.3195077; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BCC LATTICES
DOPED MATERIALS
ENERGY TRANSFER
ERBIUM IONS
ERBIUM OXIDES
EXCITATION
EXCITED STATES
IMPURITIES
LATTICE PARAMETERS
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
POLYCRYSTALS
POPULATION INVERSION
RADIOWAVE RADIATION
SILICON
SILICON SOLAR CELLS
SPUTTERING
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
YTTRIUM OXIDES
CHALCOGENIDES
CHARGED PARTICLES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
CUBIC LATTICES
DIRECT ENERGY CONVERTERS
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EQUIPMENT
ERBIUM COMPOUNDS
FILMS
IONS
LUMINESCENCE
MATERIALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTON EMISSION
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
RADIATIONS
RARE EARTH COMPOUNDS
SEMIMETALS
SOLAR CELLS
SOLAR EQUIPMENT
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS