A high-sensitivity long-lifetime phosphorescent RIE additive to probe free volume-related phenomena in polymers. - Dini, Valentina Antonia; Gradone, Alessandro; Villa, Marco; Gingras, Marc; Focarete, Maria Letizia; Ceroni, Paola; Gualandi, Chiara; Bergamini, Giacomo (Chemical Communications, 2023)