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Evidence of Organic Luminescent Centers in Sol–Gel‐Synthesized Yttrium Aluminum Borate Matrix Leading to Bright Visible Emission
Author(s) -
Burner Pauline,
Sontakke Atul D.,
Salaün Mathieu,
Bardet Michel,
Mouesca JeanMarie,
Gambarelli Serge,
Barra AnneLaure,
Ferrier Alban,
Viana Bruno,
Ibanez Alain,
Maurel Vincent,
GautierLuneau Isabelle
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201706070
Subject(s) - photoluminescence , calcination , electron paramagnetic resonance , yttrium , luminescence , boron , amorphous solid , photochemistry , radical , molecule , materials science , thermoluminescence , chemistry , analytical chemistry (journal) , crystallography , organic chemistry , nuclear magnetic resonance , catalysis , oxide , physics , optoelectronics
Yttrium aluminum borate (YAB) powders prepared by sol–gel process have been investigated to understand their photoluminescence (PL) mechanism. The amorphous YAB powders exhibit bright visible PL from blue emission for powders calcined at 450 °C to broad white PL for higher calcination temperature. Thanks to 13 C labelling, NMR and EPR studies show that propionic acid initially used to solubilize the yttrium nitrate is decomposed into aromatic molecules confined within the inorganic matrix. DTA‐TG‐MS analyses show around 2 wt % of carbogenic species. The PL broadening corresponds to the apparition of a new band at 550 nm, associated with the formation of aromatic species. Furthermore, pulsed ENDOR spectroscopy combined with DFT calculations enables us to ascribe EPR spectra to free radicals derived from small (2 to 3 rings) polycyclic aromatic hydrocarbons (PAH). PAH molecules are thus at the origin of the PL as corroborated by slow afterglow decay and thermoluminescence experiments.