Open AccessEu^3+ reduction and efficient light emission in Eu_2O_3 films deposited on Si substrates
Author(s) -
Gabriele Bellocchi,
G. Franzó,
Fabio Iacona,
Simona Boninelli,
M. Miritello,
Tiziana Cesca,
F. Priolo
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.005501
Subject(s) - photoluminescence , materials science , annealing (glass) , transmission electron microscopy , sputtering , sputter deposition , diffraction , quantum efficiency , optoelectronics , thin film , luminescence , analytical chemistry (journal) , silicon , optics , nanotechnology , chemistry , physics , chromatography , composite material
A stable Eu3+ → Eu2+ reduction is accomplished by thermal annealing in N2 ambient of Eu2O3 films deposited by magnetron sputtering on Si substrates. Transmission electron microscopy and x-ray diffraction measurements demonstrate the occurrence of a complex reactivity at the Eu2O3/Si interface, leading to the formation of Eu2+ silicates, characterized by a very strong (the measured external quantum efficiency is about 10%) and broad room temperature photoluminescence (PL) peak centered at 590 nm. This signal is much more efficient than the Eu3+ emission, mainly consisting of a sharp PL peak at 622 nm, observed in O2-annealed films, where the presence of a SiO2 layer at the Eu2O3/Si interface prevents Eu2+ formation.