Relation between material structure and photoluminescence properties in yttrium–aluminum borates phosphors

Glassy yttrium and aluminum borate powders (g-YAB) were synthesized by the polymeric precursor method (modified Pechini). We report here a detailed study of structural, spectroscopic, optical characterizations g-YAB powders, involving several complementary techniques: thermal analysis, X-ray powder diffraction, electron microscopy combined with IR, nuclear magnetic resonance, paramagnetic resonance spectroscopies. All these results, directly correlated photoluminescence (PL) properties phosphors, allow us to argue that PL emissions come from large polyaromatic molecules auto-generated organic precursors trapped in glassy network during treatments. These extended aromatic (seven rings more corresponding polycyclic hydrocarbons) must have been produced pyrolysis treatment which fraction protons was replaced calcination process hydroxyl groups, or other oxygen-containing groups. Substituting critical materials reduction energy consumption key functional devices, such as LED lighting, are major concerns chemistry research. In this context, search for new without rare earths, has given rise extensive publications. particular, defects-related luminescent carboneous species very promising, they exhibit broad visible range. Moreover, soft chemical routes at moderate temperatures. However, mechanisms involved their poorly understood. on synthesis powders–a broad-emission phosphor–using low-cost versatile method. chemical, spectroscopic analyses link inorganic matrix structure intense PL. The is amorphous, its evolution not photoluminescence. coupling results (e.g., PL, EPR) DFT calculations, we specified molecular nature emitting centers hydrocarbons, coronene circumcoronene molecules. Thus, highly original an important step understanding identification family promising phosphors.