New Transparent Rare‐Earth‐Based Hybrid Glasses: Synthesis, Luminescence, and X‐Ray Imaging Application

ABSTRACT Metal–organic hybrid glasses have recently emerged as the fourth member in the glass family due to its versatile hosting ability to various functional ions. However, no luminescent ions have been successfully introduced into hybrid glasses to date. Here, we reported a benign desolvation method, whereby rare‐earth‐based hybrid glasses (RE(NO3)3(C5H2N4)2 glasses) were rapidly formed within 1 h at a low temperature down to 140°C. Such a facile synthesis was applicable to the full rare‐earth family, including Y, Sc, and lanthanide series. The hybrid glasses exhibited not only a high transparency of over 88% but also a high luminescent quantum yield of up to 70%, which demonstrated a high spatial resolution in X‐ray imaging screen. Hydrogen bond played a key role in maintaining the structural integrity of the organic‐metal framework, which in turn promoted the radiative recombination of excited states including both singlet and triplet states of organic moiety (4,5‐dicyanoiazole, or DCI). An efficient energy transfer from DCI to luminescent lanthanide ions, also known as the antenna effect, was probed by both steady‐state and time‐resolved spectroscopy. Apart from the luminescent hybrid glasses, the incorporation of inert rare‐earth ions such as La, Y, and Lu generated a transparent glass of enhanced room‐temperature phosphorescence. This work not only improved the synthesis toolbox of metal–organic hybrid glasses, but also provided an ideal transparent matrix for the energy‐transfer investigation between organic linker and rare‐earth ions.