Rare earth doped organic–inorganic hybrid polyhedral oligomeric silsesquioxane phosphors applied for flexible sheet and anti-counterfeiting

Abstract

We have developed organic–inorganic hybrid polyhedral oligomeric silsequioxane (POSS) type monomer ligand 2,6-pyridinediamine-bis-propanylheptaisobutyl POSS (PDC-POSS) and synthesized rare earth (RE =Eu3+) doped hybrid complex PDC-POSS phosphors. The PDC-POSS precursor was prepared using (3-aminopropyl)heptaisobutyl POSS, 2,6-pyridinedicarboxylic acid chloride (PDC) as the host material, and then coordinated with RE3+ using europium nitrate regents to synthesize PDC-POSS:Eu3+ phosphors. The photoluminescence (PL) spectra of the PDC-POSS:Eu3+ hybrid phosphors were detected at 592, 616, 649, 693 nm under UV light (λ= 288 nm) excitation. In addition, the synthesized hybrid phosphors showed red light emission under UV light. The phosphors were demonstrated on a flexible sheet that could be applied for red emitting LEDs, and for anti-counterfeiting, which requires the film to remain hidden and identifiable only by UV light.