Designing of Praseodymium Oxide Nanoparticle-Based Photoluminescent Composite Films Using Polyurethane Matrix

Praseodymium oxide nanoparticle-embedded composite films were prepared using praseodymium nitrate and transparent urethane resin. The prepared films were further irradiated with ultraviolet (UV) light, and subsequently, their microstructure and optical properties were investigated. The color of the composite films turned from pale green (close to the precursor color) to reddish brown owing to UV irradiation. Pr6O11 particles were found to be present in the obtained films, and the particle size in the films increased upon increasing the UV irradiation time. The films obtained after UV irradiation showed absorption peaks at 444, 468, 483, 592, and 1020 nm, which were attributed to H-3(4)-> P-3(2), P-3(1), P-3(0), D-1(2), and (1)G(4), respectively, corresponding to the 4f-4f transition of Pr3+. The composite films exhibited photoluminescence with a peak at 605 nm corresponding to the D-1(2)-> H-3(4) transition of Pr3+ up on excitation with 444 nm light.